Microbiology with Diseases by Taxonomy Chapter 3 Answers

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Microbiology with Diseases by Taxonomy Chapter 3 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 3 Answers 1CM
The following concept map illustrates the properties of gram positive and gram negative cell walls. The gram stain separates bacteria that have a thick layer of peptidoglycan as a cell wall, which stain purple, from gram negative bacteria, which have a thin peptidoglycan layer and an outer membrane, and stain pink.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 1CT
Golgi body is the shipping department of the cell. Large molecules from the cell are received, processed, and packaged for export by the Golgi body. The secretions of Golgi body packages are known as secretory vesicles. Golgi bodies are made up of flattened hollow sacs, which are circumscribed by a phospholipid bilayer.
Chemical that prevents the Golgi function leads to different problems in the human body such as respiratory, digestive, and hormonal issues.
The respiratory tract would dry out, making breathing and gas exchange more difficult. Lack of digestive enzyme secretion would lead to digestive problems. These affect the human body immediately.
It does not affect bacterial cells because they do not have Golgi bodies, as they are prokaryotes.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 1M

  1. A gelatinous and sticky like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyces is “sugar cup”. It is made up of polysaccharides and polypeptides, which protects the cell from drying. Glycocalyces of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria, to attach the surfaces.
    Hence, the term “Glycocalyx” perfectly matches the description (D) “sugar cup” composed of polysaccharides and or polypeptides.
  2. Bacterial flagellum is made up of protein known as flagellin. They are long whip like structures, which extends to the surface of the cell. Flagella are composed of three parts. They are filament, hook, and basal body. Bacteria flagella sense external wetness and also inhibit their growth in dry habitats. Hook, rod, and rings together allow the filament to rotate 3600.Eukaryotic flagella are mainly composed of globular protein known as tubulin. The tubulin is arranged in chains to form hollow micro tubules. Nine pairs of the micro tubulins are surrounded by the two micro tubules in the center. This 9+2 arrangement of micro tubulins is present in all flagellated eukaryotic cells. Eukaryotic flagella are found at one pole of the cell.
    Hence, the term “Flagella” perfectly matches the description (B) long whip, (H) made of tubulin in eukaryotes, and (I) made of flagella in bacteria.
  3. Bacterial flagella are long whip like structures, which extends at the surface of the cell. Flagella are composed of three parts. They are filament, hook, and basal body. Bacteria flagella sense external wetness and inhibit the growth in dry habitats. Hook, rod, and rings allow the filament to rotate 3600.Spirochetes are spiral shaped bacteria. They have flagella at both ends known as endoflagella. Axial filaments are placed between the cytoplasmic membrane and outer membrane. Axial filament is composed of endoflagella, which is revealed by the cross section of the spirochete. It rotates around the cell, causing the spirochete to give cross screw movement through its medium, which helps them to invade human tissues.
    Hence, the term “axial filaments” perfectly matches the description (F) responsible for motility of spirochetes.
  4. Cilia are hair like structures that helps in movement of eukaryotic cells. They spread along the surface of the cell. They are not present in prokaryotes. They are composed of tubulin microtubules. Single cell may contain thousands of cilia. They arrange in‘9+2’pairs in their shafts and 9+0 triplets in their basal bodies.
    Thus, the term “Cilia” perfectly matches the description (H) made of tubulin in eukaryotes.
  5. Fimbriae are rod like proteinaceous extensions in bacteria. Fimbriae are short, numerous, non-motile structures, that are sticky and bristle like projections. Bacterial cell contain hundreds of fimbriae. They play important role in bio-films.
    Thus, the term “Fimbriae” perfectly matches the description (A) bristle like projections found in quantities of 100 or more and (E) short, numerous, non-motile projections.
  6. Pili are also known as conjugation pili. Pili are tubules containing a protein named pilin. They are longer than fimbriae, but shorter than flagella. They are not used in motility. They are mainly responsible in conjugation to transfer DNA from one cell to another cell.
    Hence, the term “Pili” perfectly matches the description (C) responsible for conjugation, (G) extensions not used for cell motility.
  7. Archaeal have fimbriae and grappling hook like structures known as hami. It serves to anchor the cells to environment surfaces. They are bristle like projections, which are non-motile and have sticky rod shaped structure. Single archaeon have more than hundreds of hami on their surface.
    Thus, the term “Hami” perfectly matches the description of (A) bristle like projections found in quantities of hundred or more, (E) short, numerous, non-motile projections, and (G) extensions not used for cell motility.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 1MC
Facilitated diffusion is the process that allows large or charged chemicals to pass across the plasma membrane, down the chemicals electrical and chemical gradients.
(a)Active transport:
Active transport is a process of transporting molecules across the cell membrane. It uses transmembrane permease proteins. Some of these proteins are called as gated channels (ports). When cell needs substance then the proteins start functioning and open the gated channels, at normal time these channels are closed.
The permease that transports only one substance at a time is known as uniport permease and if a permease moves two substances in opposite direction that means one substance transported into the cell at the same time another substance transported out of the cell is known as antiports permease. Symports are single carrier proteins that allow transport of two molecules together across the plasma membrane in the same direction. Hence, this option is incorrect.
(b)Facilitated diffusion:
Electrically charged or large molecules are blocked by the phospholipid bilayer, so they do not cross the membrane. Cytoplasmic membrane contains proteins known as integral proteins; they act as carriers to move specific molecules to enter into or out of the cell through the process of diffusion. This process is termed as facilitated diffusion. Cell does not utilize its energy in facilitated diffusion. The electrochemical gradient provides the energy in this process. Some protein channels allow the passage of chemicals. Hence, this option is correct.
(c)Endocytosis:
Endocytosis is a type of active transport in which physical manipulation of cytoplasmic membrane around the cytoskeleton involved. This happens when the membrane expand to form pseudopodia surrounding the substance and engulfed into the cell. This process is termed as Phagocytosis, if the ingested particles are in the form of solid. If the engulfed particles are liquid in form, it is termed as Pinocytosis. Hence, this option is incorrect.
(d)Pinocytosis:
The incorporation of liquids into the cell by endocytosis is known as Pinocytosis. Endocytosis incorporates nutrients in to the cells and enclose in a food vesicle. Hence, this option is incorrect.
Hence, the correct answer is (b) Facilitated diffusion which is the process that allows large or charged chemicals to pass across the plasma membrane, down the chemicals electrical and chemical gradients.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 1SA
Diffusion down a concentration gradient:
Explanation
The net movement of a chemical from high concentration area to low concentration area is known as diffusion. It does not require energy, from the cell. Moreover, the process can undergo even in the absence of membranes by considering random walk in diffusing the particles. Thus, the process does not involve any chemical energy.
Additionally, chemicals that are lipid soluble can diffuse through lipid membrane, when they are small. For example, the smaller molecules that facilitate in the process of diffusion are: carbon dioxide, oxygen, alcohol, and fatty acids. These molecules freely diffuse through cytoplasmic membrane, whereas larger molecules like glucose and proteins cannot diffuse through diffusion.
Furthermore, diffusion brings nutrient and also removes (without spending energy) wastes from the cell. Its main function is to move molecules in or out of the cell. Thus, the process creates energy and other essential nutrients in a cell.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 2CT
Methylene blue is an aqueous or an alcoholic solution of a single basic dye. It is a heterocyclic aromatic chemical compound. It is a cationic dye with maximum absorption of light of about 670 nm.
It helps in study of different shapes of the cells and structures of the microorganisms. It mainly helps in examining DNA (deoxyribonucleic acid) or RNA (ribonucleic acid).
Mitochondria and nucleus are the two structures of yeast cell that get stained by Methylene blue due to the presence of DNA in them.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 2M

  1. Ribosomes are large and complex molecules present in all prokaryotes and eukaryotes, function is protein synthesis. It contains two subunits. The large subunit joins the amino acids and forms the polypeptide chain. The smaller subunit is reads mRNA (messenger RNA).
    Bacterial cells have thousands of ribosomes in their cytoplasm that gives grainy appearance to cytoplasm. The size of the ribosomes and other cellular structures are expressed in Svedberg’s (S). Svedberg units determine the sedimentation rate. Ribosomes in prokaryotes are 70S and in eukaryotes ribosomes are 80S.
    Hence, the term “Ribosome,” perfectly matches the description (A) site of protein synthesis.
  2. Internal network of fibers and tubules in eukaryotic cells is known as cytoskeleton. They plays important role in forming a base shape of cell. Moreover, acts as an anchor organelles and function in the movement of organelles within the cytosol.They allow contraction of the cell. They are composed of tubulin, micro tubules, thinner micro filaments, and intermediate filaments. They play vital role in the intra cellular transport and cellular division.
    The term “Cytoskeleton,” perfectly matches the description (d) allows contraction of the cell.
  3. Centriole is a cylinder shaped cell structure. Some fungal cells and animal cells consist of two centrioles. Plants, algae, and fungi do not have centrioles. Centrioles consist of nine sets of tubulin microtubule triplets arranged in 9+0. It is seen in the base of eukaryotic flagella and cilia. They play important role in mitosis, cytokinesis, and formation of flagella and cilia.
    Thus, the term “Centriole,” perfectly matches the description (F) contains microtubules in “9+0” arrangement.
  4. The largest organelle in the cell is known as nucleus. It is spherical in shape. Some cells have single nucleus and some other have multi nucleus. It is the site of DNA in eukaryotes. Nucleus is also known as the control center of the cell because it consists of genetic instructions in the form of DNA.
    Thus, the term “Nucleus,” perfectly matches the description (E) site of most DNA in eukaryotes.
  5. Eukaryotic cells contain spherical and elongated structures known as mitochondria. Their membrane is made by the phospholipid bilayer. The folded membrane is called as cristae; it increases the inner membrane surface area. It is also called as power house of the cell because its cristae synthesize most of the ATP molecules in the eukaryotic cells.
    The term “Mitochondria,” perfectly matches the description (I) its internal membranes are sites for ATP production.
  6. The light-harvesting structures present in the photosynthetic eukaryotes are known as chloroplasts. They have two phospholipid bilayer membrane and DNA. They produce few polypeptides by their own 70S ribosomes. Chloroplast pigments gather light energy to produce ATP from sugar and carbon dioxide.Thus, the term “Chloroplast” perfectly matches the description (G) light-harvesting organelle.
  7. Net like arrangement of flattened hollow tubules in the nuclear envelope are known as endoplasmic reticulum. Endoplasmic reticulum transports the cytoplasm of eukaryotic cells. They function in the transport systems and are found in two forms. The smooth endoplasmic reticulum plays an important role in lipid synthesis and transport. Rough endoplasmic reticulum is made of ribosomes that are inserted in lumen and transported throughout the cell.
    Thus, the term “Endoplasmic reticulum,” perfectly matches the description (c) function as the transport system within eukaryotic cell.
  8. Golgi body is a shipping department of the cell. It receives and packs large molecules, for export from the cell. The secretions of Golgi body packages are known as secretory vesicles. Golgi bodies are made up of flattened hollow sacs, which are circumscribed by a phospholipid bilayer.Thus, the term “golgi body,” perfectly matches the description (H) packages large molecules for export from the cell.
  9. Peroxisomes are derived from endoplasmic reticulum. They have enzymes like oxidase and catalase. These enzymes degrade poisonous metabolic wastes (free radicals and hydrogen peroxide) which results from oxygen dependent reactions. Peroxisomes are present in all types of eukaryotic cells.
    Thus, the term “Peroxisomes,” perfectly matches the description (B) contains enzymes to neutralize hydrogen peroxide.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 2MC
The statement, “Growth and reproduction occurs simultaneously,” is true.
(a) Growth and reproduction may occur simultaneously in living organisms:
Increase in size of living thing is known as growth. All living things can grow. Non living things cannot grow. Living things are normally reproduce themselves. Reproduction is accomplished by either sexually or asexually. They increase in number and producing more organisms. Thus, the statement, “Growth and reproduction occurs simultaneously,” is a true statement. Hence, this option is incorrect.
(b) All living organisms must reproduce to be considered alive:
Increase in size of living thing is known as growth. All living things can grow. Non living things cannot grow. Living things are normally reproduce themselves. Reproduction is accomplished by either sexually or asexually. They increase in number and producing more organisms. Growth and reproduction may occur simultaneously in living organisms. A living organism must reproduce to be considered alive is false statement. Hence, this option is correct.
(c)Living things may stop growing and reproducing, yet still be alive:
All living things can grow, they can increase in size. Organisms have the ability to reproduce, they increase in number. Growth and reproduction may occur simultaneously in living organisms. If organism will died then growth and reproduction will be ceased. Living things may stop growing and reproducing yet still be alive is true statement. Hence, this option is incorrect.
(d)Normally, living organisms have the ability to grow and reproduce themselves:
Increase in size of living thing is known as growth. All living things can grow. Non living things cannot grow. Living things are normally reproduce themselves. Reproduction is accomplished by either sexually or asexually. They increase in number and producing more organisms. Growth and reproduction may occur simultaneously in living organisms. Normally, living organisms have ability to grow and reproduce themselves is true statement. Hence, this option is incorrect.
Hence, the correct answer is (b) a living organism must reproduce to be considered alive is not true statement. Growth and reproduction occurs simultaneously.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 2SA
Flagellar arrangements in bacteria:
Explanation
The important structure used in the motility of bacteria is known as flagella. Flagella are used to move towards favorable environments like food or light. They are long structures, which extend the surface of the cell. Moreover, it senses the external wetness and inhibiting their growth in dry habitats.
Bacterial flagellum is composed of protein known as flagellin. They are made up of three parts; filament, hook, and basal body. Filament is long and thin, it about 20nm in diameter.
Hook and basal body are composed of different proteins. The hook, rod, and rings allow the filament to rotate 3600. Flagella that are spread across the surface of the cell are known as peritrichous and flagella arrange only at ends are known as polar flagella.
Spirochetes are spiral shaped bacteria. They have flagella at both ends known as endoflagella.
Axial filaments are placed between the cytoplasmic membrane and outer membrane.Axial filament is composed of endo-flagella, which is revealed by the cross section of the spirochete. It rotates around the cell, causing the spirochete to give cross screw movement through its medium, which helps them to invade human tissues.
Bacterial flagella rotate more than 100,000 rpm and it change from counter clockwise to clock wise direction. Flagella have receptors, which gives signals to flagella to adjust their speed and direction of rotation.
The flagella movement in response to stimulus is known as taxis. Light stimulus is known as phototaxis and chemical stimulus is known as chemotaxis.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 3CT

  • Paul Ehrlich, a German physician, observed that chemicals with selective toxicity kills only pathogens and do not harm human cells. He identified a toxic molecule known as magic bullet, which specifically binds pathogens and destroy them. He was also successful in chemotherapy of sleeping sickness.
  • Chemotherapeutic drug is a chemical substance, which is used in disease treatment. They have selective toxicity that kills or inhibit the microbial pathogen without harming human cells. The role of administration plays important role in chemotherapy. It is mainly used for cancer treatment.
  • The drug is able to reach the site of infection. It shows adverse effect on different mechanisms of the bacterial cell, such as protein synthesis, cell wall synthesis, nucleic acid synthesis, cell membrane synthesis, and other metabolic pathways. Examples of such drugs are penicillin, sulfonamides, streptomycin, and cephalosporin.
  • Drug targeting biochemicals are toxic to bacteria, but not to human cells. Since the metabolic pathways present in the bacteria are different from human metabolic pathways, they inhibit only bacterial cell.
  • The bacteria cells are different from human cells in many aspects. They contain cell wall, but human cells do not. Therefore, these drugs can act only on bacterial cells and destroy them without effecting human cells.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 3MC
The important structure of bacteria is known as flagella. It mainly used for the move towards food or light. Flagella are a long structure that extends the surface of the cell.
(a) Archaeal flagella:
Archaeal flagella resembles to the bacterial flagella. It contains basal body, hook, and filament. They are 10-14nm in diameter. They can grow with addition of subunits at the base of the filament. Their flagella are attached by the sugar molecules. Their energy is stored in molecules of ATP (Adenosine Triphosphate). They can rotate both clockwise and counterclockwise directions. Hence, this option is incorrect.
(b) Bacterial flagella:
The most important structures that are used for the motility of bacteria are known as flagella. Flagella are mainly used to move towards favorable environments like food or light. They are long structures which extend the surface of the cell. It senses the external wetness and inhibiting their growth in dry habitats. Hence, this option is incorrect.
(c) Eukaryotic flagella:
Eukaryotic flagella differ in structure and function from prokaryotic flagella. They attach within the cytoplasmic membrane. Their internal structures push cytoplasmic membrane out around them. Eukaryotic flagella are mainly composed by the globular protein known as tubulin.
This tubulin is arranged in chains to form hollow micro tubules. Nine pairs of the micro tubulins are surrounded by the two micro tubules in the center. This 9 + 2 arrangement of micro tubulins is present in all flagellated eukaryotic cells. Hence, this option is correct.
(d) All prokaryotic flagella:
Examples of Prokaryotic flagella are bacterial flagella and archaeal flagella. Bacterial flagella are long structures which are extended the surface of the cell. Flagella composed of three parts. They are filament, hook and basal body. Archaeal flagella resembles to the bacterial flagella, consisting of a basal body, hook and filament. Archaeal flagella extend outside the cell and not covered by the membrane. Hence, this option is incorrect.
Hence, the correct answer is (c) Eukaryotic flagella which contain 9 + 2 arrangement of microtubules.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 3SA
Cytosol:
Explanation
Cytosol is defined as the liquid portion in the cytoplasm. It was first introduced by H.A Lardy in 1965. It is an intra cellular fluid. It contains water, suspended substances, ions, carbohydrates, proteins, lipids and wastes. The prokaryotic cytosol contains the cell’s DNA (deoxyribonucleic acid) in a region known as nucleoid. It contains 70% of the water.
In addition, prokaryotes do not have phospholipid membrane, which surrounds DNA. Single, circular DNA molecules are organized as chromosomes in the bacteria. Some bacteria like vibrio cholerae unusually have two chromosomes.
Furthermore, chemical reactions occur in cytosol; for instance, enzyme present within the cytosol function to synthesis amino acids and degrade sugar.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 4CT

  • The diffusion of water molecules across a selectively permeable membrane is known as osmosis.
  • Proteins, amino acids, salts, or glucose do not freely penetrate into the membrane, so they cannot diffuse.
  • When solutions have same concentration on either side of a selectively permeable membrane they are called isotonic solutions.
  • When the concentration of solutions is not equal, then the solution containing higher concentration of solutes is known as hypertonic and the solution containing lower concentration of solutes is known as hypotonic.
  • Water molecules move based on the concentration gradient that is hypotonic solution to hypertonic solution.
    Some bacterial toxins cause the cells lining the digestive tract to secrete ions.
  • This makes the contents of the track hypertonic. As these cells secrete salts, it induces the patient to lose more amount of water and make him/her to shrivel.
  • The patient’s water balance will be disturbed or imbalanced and results in severe dehydration. This condition many even lead to death of the patient, it there is over dehydration.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 4MC
(a) Symports:
Active transport is a process of transporting molecules across the cell membrane. It uses transmembrane permease proteins. Some of these proteins are called as gated channels (ports). When cell needs substance then the proteins start functioning and open the gated channels, at normal time these channels are closed.
The permease that transports only one substance at a time is known as uniport permease. Symports are single carrier proteins that carry two molecules or substances across the plasma membrane in the same direction. Hence, this option is incorrect
(b) Antiports:
Active transport is a process of transporting molecules across the cell membrane. It uses transmembrane permease proteins. Some of these proteins are called as gated channels (ports). When cell needs substance then the proteins start functioning and open the gated channels, at normal time these channels are closed.
The permease that transports only one substance at a time is termed as uniport permease. If a permease moves two substances in opposite direction that means one substance transported into the cell at the same time another substance transported out of the cell is known as antiports permease. Hence, this option is incorrect.
(c) Carrier proteins:
The net movement of a chemical from high concentration area to low concentration area is known as diffusion. Carrier proteins are most associated with diffusion. It does not require energy from the cell. It occurs even in the absence of cells or membranes.
In addition, only small or lipid soluble chemicals are diffused across the lipid portion of the membrane. For example: oxygen, carbon dioxide, alcohol and fatty acids that can freely diffuse through cytoplasmic membrane, whereas molecules like proteins and glucose cannot diffuse. Hence, this option is correct.
(d) Endocytosis:
Endocytosis is a type of active transport in which physical manipulation of cytoplasmic membrane around the cytoskeleton involved. This happens when the membrane expand to form pseudopodia surrounding the substance and ingesting into the cell. It is termed as phagocytosis, if solid particles are ingested by the cell and it is termed as pinocytosis, if liquid is ingested by the cell. Hence, this option is incorrect.
Hence, the correct answer is (c) carrier proteins which are most associated with diffusion.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 4SA
The membrane below the glycocalyx and the cell wall is known as cytoplasmic membrane. It is also known as cell membrane or plasma membrane. Thickness of cytoplasmic membrane is 8nm and composed of phospholipids and proteins.
Cytoplasmic membrane structure is referred to phospholipid bilayer. Phospholipid molecule is bipolar. Cytoplasmic membrane of bacteria is composed of integral proteins. Peripheral proteins are attached loosely to the membrane on one or another side. Cell membrane proteins act as recognition proteins, enzymes, receptors and carries.
It controls the movement of substances in and out of the cell. The main function of the cytoplasmic membrane is to protect the cell from the surroundings. It also provides shape to the cell. It mainly involves in different cellular processes (cell adhesion, ion conductivity and cell signaling).

Microbiology with Diseases by Taxonomy Chapter 3 Answers 5CT
Central vacuole is the large organelle, which is surrounded by the second membrane. It is a prominent feature of many plant cells. Vacuoles are the membranous sacs. They play important role in the transfer and storage of chemicals within the eukaryotic cells.
Plants and algal cells contain large vacuoles in the center of the cell for storing lipids, starch, and other substances. The rest of the cytoplasm is pressed against the cell wall in a thin layer, so the central vacuole is very large.
Hence, the large organelle surrounded by the second membrane is central vacuole. It is the membrane responsible for the change in electrical charge from -70 millivolts to -90 millivolts.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 5MC
(a) Nucleoid:
The liquid portion of the cytoplasm is known as cytosol. The nuclear region in prokaryotic cytosol is known as nucleoid. Nucleoid has no membrane and it contains a single circular molecule of DNA (Deoxyribonucleic acid). They lack in phospholipid membrane, which surrounds this DNA. Hence, this option is incorrect.
(b) Glycocalyx:
A gelatinous and sticky like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyxes is “sugar cup.” It is made up of polysaccharides and polypeptides and protects cells from drying. Glycocalyces of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria to attach the surfaces. It does not form pseudopodia for mobility of an organism. Hence, this option is incorrect.
(c) Cilia:
Cilia are hair like structures that helps in movement of eukaryotic cells. They spread along the surface of the cell. They are not present in prokaryotes. They are composed of tubulin microtubules. Single cell may contain thousands of cilia. They arrange in‘9+2’pairs in their shafts and 9 + 0 triplets in their basal bodies. Hence, this option is correct.
(d) Circular DNA:
Nucleus is the control center of the cell because it consists of genetic material in the form of DNA. Nucleoid is present in the nuclear region of the prokaryotic cytosol. It does not have membrane, but it consist of single circular DNA. Hence, this option is incorrect.
Hence, the correct answer is (c) Cilia which is not associated with prokaryotic organisms.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 5SA
Living things performs functions like growth, reproduction, metabolism, responsiveness, movement and respiration, which are absent in non living things. Living things are made up of one or more cells.
Growth: Increase in size of an organism is known as growth. All living things can grow and Non living things cannot. It results in to morphogenesis and differentiation.
Reproduction: Individual organisms are produced from their parents, is known as reproduction. It accomplished by either sexually (animals) or asexually (bacteria). They increase in number and producing more organisms.
Metabolism: All chemical reactions are involved in maintain the living state of the cell is known as metabolism. It controls the chemical reactions in an organism and cellular structure.
Responsiveness: Every living thing responds to its atmosphere. They can change internal and external properties based on the changing conditions around them. Living things can respond to temperature, light, and sound etc.
Movement: All living things can move from one place to another place.
Respiration: All things can breathe in order to carryout energy producing process.
Living things also shows variations from the non living things by the following properties. They are; survivability, genetic composition, mutation, evolution, cellular composition, development, homeostasis and organization.
These are the differences between the living things and nonliving things.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 6CT
Figure 3.2 represents the typical prokaryotic gram positive cell wall. The cell wall is thick and there is no indication of external lipid bi layer compared to the gram negative bacteria. In gram negative bacteria the cell wall is thin with external lipid bi layer.
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. Bacterial cell walls are composed of peptidoglycan. It also resists antimicrobial drugs. It plays an important role in treatment of bacterial diseases with specific antibiotics.
Peptidoglycan is a complex polysaccharide and is composed of two types of sugar molecules, N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM). NAG and NAM are covalently linked by the chains, and they are joined by four amino acids. They cover the total surface of the cell.
Gram positive bacterial cell wall contain thick layer of peptidoglycan. It also contains a chemical known as teichoic acid, which helps in the passage of ions through the cell wall. In gram staining procedure, cell wall retains crystal violet dye, so they appear in purple color.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 6MC
(a) Svedbergs are not exact but are useful for comparisons: Bacterial cells have thousands of ribosomes in their cytoplasm that gives a grainy appearance to cytoplasm. The size of the ribosomes and indeed other cellular structures are expressed in Svedbergs (S). Svedbergs are determines the sedimentation rate during high-speed centrifugation. Ribosomes in prokaryotes are 70S and in eukaryotes ribosomes are 80S. They are not exact but are useful for comparisons if the false statement. Hence, this option is incorrect.
(b) Svedbergs are abbreviated “sv”:
Protein synthesis occurring in cells sites is known as ribosomes. In bacterial cytoplasm thousands of the ribosomes are present. The size of the ribosomes and indeed other cellular structures are expressed in Svedbergs (S). Svedbergs are determining the sedimentation rate. They are abbreviated “sv” is the false statement. Hence, this option is incorrect.
(c) Svedbergs are prokaryotic in nature but exhibit some eukaryotic characteristics:
Bacterial cells have thousands of ribosomes in their cytoplasm that gives a grainy appearance to cytoplasm. The size of the ribosomes and indeed other cellular structures are expressed in Svedbergs (S). Svedbergs are determines the sedimentation rate during high-speed centrifugation. Ribosomes in prokaryotes are 70S and in eukaryotes ribosomes are 80S. So they are prokaryotic in nature but exhibit some eukaryotic characteristics is the false statement. Hence, this option is incorrect.
(d) Svedbergs are an expression of sedimentation rate during high-speed centrifugation:
Bacterial cells have thousands of ribosomes in their cytoplasm that gives a grainy appearance to cytoplasm. The size of the ribosomes and indeed other cellular structures are expressed in Svedbergs (S). Svedbergs are determines the sedimentation rate during high-speed centrifugation. Ribosomes in prokaryotes are 70S and in eukaryotes ribosomes are 80S. So they are an expression of sedimentation rate during high-speed centrifugation is the true statement. Hence, this option is correct.
Hence, the correct answer is (d) they are an expression of sedimentation rate during high-speed centrifugation. Svedbergs are determines the sedimentation rate during high-speed centrifugation.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 6SA
Reproduction result in increasing in number of organism. Living things normally reproduce themselves. Growth and reproduction may occur simultaneously in living organisms. Living things stop growing and reproduction, yet still alive.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 7CT
The most important structures that are used for the motility of bacteria are known as flagella. Flagella are mainly used to move towards favorable environments like food or light. They are long structures, which extend beyond the surface of the cell. It senses the external wetness and inhibiting their growth in dry habitats.
Bacterial flagellum is composed of protein known as flagellin. They are made up of three parts; filament, hook and basal body. Filament is long and thin, and is about 20 nm in diameter.
Hook and basal body are composed of different proteins. The hook, rod and rings allow the filament to rotate 3600. Flagella that are spread across the surface of the cell are known as peritrichous and flagella arrange only at ends are known as polar flagella.
Bacterial flagella rotate more than 100,000 rpm and it can also change its direction from counter clockwise to clock wise. Flagella have receptors, which gives signals to flagella to adjust their speed and direction of rotation.
Hence, the long projections with basal body in the cell wall are known as flagella. It is a prokaryotic. The cell uses this structure mainly for motility.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 7MC
Bacterial cell walls are composed of peptidoglycan. It is a complex polysaccharide.
(a) The cell walls of Bacteria are composed of peptidoglycan:
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. It also resists antimicrobial drugs. It plays an important role in treatment of bacterial diseases with specific antibiotics. Bacterial cell walls are composed of peptidoglycan.
Peptidoglycan is a complex polysaccharide and is composed of two types of sugar molecules, N-acetyl muramic acid (NAM), and N-acetyl glucosamine (NAG). NAG and NAM are covalently linked by the chains and they are joined by four amino acids. They cover the total surface of the cell. Hence, this option is correct.
(b) Peptidoglycan is a fatty acid:
Bacterial cell walls are composed of peptidoglycan. Peptidoglycan is not a fatty acid. Hence, this option is incorrect.
(c) Gram positive bacterial walls have a relatively thin layer of peptidoglycan anchored to the cytoplasmic membrane by teichoic acids:
Gram-positive bacterial cell wall contain thick layer of peptidoglycan. It also contains a chemical known as teichoic acid which helps in the passage of ions through the cell wall. In gram staining procedure, cell wall retains crystal violet dye, so they appear in purple color. Hence, this option is incorrect.
(d) Peptidoglycan is found mainly in the cell walls of fungi, algae and plants:
Bacterial cell walls are composed of peptidoglycan. Peptidoglycan is not fixed to fungi, algae, or plants but contain mostly in bacterial cells. Hence, this option is incorrect.
Hence, the correct answer is (a) the cell walls of Bacteria are composed of peptidoglycan which is a complex polysaccharide.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 7SA
All cells are described as either prokaryotes or eukaryotes. Bacterial cells are prokaryotic, and algae are eukaryotic organisms.
Both prokaryotic and eukaryotic cells are surrounded by a cell wall. Cell wall gives structure and shape to the cell and also protects from osmotic forces.
Diffusion is facilitated by the channel proteins that are present in both prokaryotes and eukaryotes.
Ribosomes are present in both prokaryotes and eukaryotes. They are made up of water and suspended proteins, carbohydrates, lipids and wastes. Cytoskeleton is present in both.
Eukaryotes have nucleus, lysosomes, golgi body, peroxisomes, endoplasmic reticulum, vacuoles, mitochondria, vesicles, and chloroplast, which are absent in prokaryotes.
Bacterial cell do not have membrane surrounding its genetic material, but it is present in algae cell.
Nucleus is present in the eukaryotes, but is absent in the prokaryotes. Eukaryotes have internal membrane that compartmentalized cellular function, but it is absent in the prokaryotes.
Translocation occurs in prokaryotes, but it is absent in the eukaryotes. Chloroplast is present in eukaryotes, whereas absent in prokaryotes.
Cilia is present in eukaryotes, but it was absent in prokaryotes. Eukaryotes are larger than prokaryotes.
These are the differences and similarities between the bacterial (prokaryotes) cells and algal (eukaryotes) cells.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 8CT
Phototaxis is a kind of locomotary movement of an organism, in response to the light stimulus. By this process, phototrophic organisms can move towards light to carryout photosynthesis most efficiently. In positive phototaxis, the organism moves towards the direction of increasing light intensity, and in negative phototaxis the movement is opposite.
Hence, as per this knowledge, I would arrange light equipment, and favorable environment in lab to encourage the growth of these organisms.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 8MC
(a) It forms pseudopodia for faster mobility of an organism:
A gelatinous and sticky-like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyxes is “sugar cup”. It is made up of polysaccharides and polypeptides and protects the cell from drying.
Glycocalyxes of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria to attach the surfaces. It does not form pseudopodia for mobility of an organism. Hence, this option is correct.
(b) It can protect a bacterial cell from drying out:
A gelatinous and sticky like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyces is “sugar cup”. It is made up of polysaccharides and polypeptides that protect the cell from drying. Hence, this option is incorrect.
(c) It hides a bacterial cell from other cells:
A gelatinous and sticky like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyces is “sugar cup”. It is made up of polysaccharides and polypeptides and protects cells from drying. Glycocalyces of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria to attach the surfaces.
It also protects the bacteria from getting recognized by the defensive cells of host. Streptococcus pneumoniae and klebsiella pneumoniae protects against the defensive cells in the respiratory tract causing pneumonia. Hence, this option is incorrect.
(d) It allows a bacterium to stick to a host:
A gelatinous and sticky like substance that surrounds outside of the cell is known as glycocalyx. It is made up of polysaccharides and polypeptides and protects cells from drying. Glycocalyces of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria to attach the surfaces. Hence, this option is incorrect.
Hence, the correct answer is (a) it forms pseudopodia for faster mobility of an organism which is not function of glycocalyx.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 8SA

  • Streptococcus pyogenes is a spherical shaped bacterium. They are gram positive facultative anaerobic bacteria.
  • They are oxidase and catalase negative; occurring in pair and long chains; and they are nonmotile and non spore forming bacteria.
  • These bacteria contain plasmids, cell wall, slime coat called capsule. They do not have vacuoles. And reproduce via conjugation and smaller in size.
  • They are responsible for many human diseases example pharyngitis, impetigo and pyogenic infection. They are hemolytic streptococci of group A.
  • They exhibit beta hemolysis on the blood agar because their capsule is made up of hyaluronic acid. They have ability to destroy red blood cells and white blood cells.
  • Entamoeba histolytica is an anaerobic parasitic protozoan; they move by amoeboid motion. Their cysts are 10-20m in diameter. They cause the disease known as amoebiasis.
  • This disease is transferred through contamination of food and water.This protozoan contains nucleus, rod shaped chromosomes and vacuoles. They do not conjugate. No cell wall is present in Entamoeba histolytica.
  • They mainly infect the digestive track of humans. They form trophozoites and are excreted in feces. The trophozoites survive for weeks in moist conditions. The symptoms of amoebiasis are abdominal pain and diarrhea.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 9CT
Neisseria gonorrhoeae is gram-negative diplococcic bacteria. This bacterium causes the disease known as gonorrhea (a sexually transmitted infection). This strain of Neisseria is pathogenic because as mentioned in the lab report, this was identified in a biofilm. Recently it has been shown that Neisseria gonorrhoeae can produce biofilms both in human host and experimental chambers. They can colonize the mucous membrane of the reproductive tract by joining with fimbriae. If they do not have fimbriae, they are non-pathogenic.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 9MC
Bacterial flagella are anchored to the cell by a basal body.
(a) Are anchored to the cell by a basal body:
The most important structures that are used for the motility of the bacteria are known as flagella. Flagella are mainly used to move towards favorable environments like food or light. They are long structures, which extend the surface of the cell. Bacterial flagella are anchored to the cell by a basal body. It senses the external wetness and inhibiting their growth in dry habitats.
Bacterial flagellum is composed of protein known as flagellin. They are made up of three parts; filament, hook and basal body. Filament is long and thin, it about 20 nm in diameter. Hook and basal body are composed of different proteins. The hook, rod and rings allow the filament to rotate 3600. Hence, this option is correct.
(b) Are composed by hami:
The most important structures that are used for the motility of bacteria are known as flagella. Flagella are mainly used to move towards favorable environments like food or light. They are long structures which extend the surface of the cell. It senses the external wetness and inhibiting their growth in dry habitats.
Archaeal have fimbriae and grappling hook like structures known as hami. It serves to anchor the cells to environment surfaces. They are bristle like projections, which are nonmotile and have sticky rod shaped structure. Single archaeon have more than hundreds of hami on their surface. Hence, this option is incorrect.
(c) Are surrounded by an extension of the cytoplasmic membrane:
Eukaryotic flagella is differ in structure and function from prokaryotic flagella. They are attaching within the cytoplasmic membrane. Their internal structures are pushing cytoplasmic membrane out around them. Hence, this option is incorrect.
(d) Are composed of tubulin in hollow microtubules is a 9+2 arrangement:
Eukaryotic flagella is mainly composed by the globular protein is known as tubulin. This tubulin is arranged in chains to form hollow micro tubules. Nine pairs of the micro tubulins are surrounded by the two micro tubules in the center. This 9+2 arrangement of micro tubulins is present in all flagellated eukaryotic cells. Hence, this option is incorrect.
Hence, the correct answer is (a) bacteria flagella are anchored to the cell by a basal body which are useful in motility.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 9SA
Cilia are hair like structures that helps in movement of eukaryotic cells. It is structurally identical to the flagella. It is made up of group of organelles called undulipodia.
They spread along the surface of the cell, and are not present in prokaryotes. Cilia are also present in paramecium and epithelial cells of metazoans (digestive system and lungs).
They are composed of tubulin microtubules. Single cell may contain thousands of cilia. They arrange in‘9+2’pairs in their shafts and 9+0 triplets in their basal bodies.
microbiology-with-diseases-by-taxonomy-chapter-3-answers-9sa

Microbiology with Diseases by Taxonomy Chapter 3 Answers 10CT
SER or smooth endoplasmic reticulum is an interconnected sac like organelle that performs many metabolic processes in a cell. This organelle synthesizes phospholipids, lipids, and steroids. And also carries out drug detoxification, steroid and carbohydrate metabolism.
If a researcher treats a cell to block the function of this organelle, it initially shows effect on the lipid synthesis, and later on steroid and carbohydrate metabolism.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 10MC
Cell Wall is an important cellular structure in classifying bacterial species as Gram- positive or Gram-negative.
(a) Flagella:
The most important structures that are used for the motility of bacteria are known as flagella. Flagella are mainly used to move towards favorable environments like food or light. They are long structures, which extend the surface of the cell. It senses the external wetness and inhibiting their growth in dry habitats. Hence, this option is incorrect.
(b)Cell wall:
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. It also resists antimicrobial drugs. It plays an important role in treatment of bacterial diseases with specific antibiotics. Bacterial cell walls are composed of peptidoglycan.Peptidoglycan is a complex polysaccharide and is composed of two types of sugar molecules, N-acetyl muramic acid (NAM) and N-acetyl glucosamine (NAG). NAM and NAG are covalently linked by the chains and they are joined by four amino acids. They cover the total surface of the cell.Gram positive bacterial cell wall contain thick layer of peptidoglycan. It also contains a chemical known as teichoic acid, which helps in the passage of ions through the cell wall. Gram negative bacteria cell wall contains a thin layer of peptidoglycan and outer membrane composed of phospholipids and proteins. Outer leaflet is composed by lipopolysaccharides.In Gram staining procedure, the gram positive bacterial cells are appear in purple color and gram negative bacterial cells appear in pink color. Based on the structure of bacterial cell wall, the classification of bacterial species is classified either gram positive or gram negative.
Hence, the correct answer is (b) Cell wall
(c) Cilia:
Cilia are hair like structures that helps in the movement of eukaryotic cells. They spread along the surface of the cell. They are not present in prokaryotes. They are composed of tubulin microtubules. Single cell may contain thousands of cilia. They arrange in‘9 + 2’pairs in their shafts and 9 + 0 triplets in their basal bodies. Hence, this option is incorrect.
(d) Glycocalyx:
A gelatinous and sticky-like substance that surrounds outside of the cell is known as glycocalyx. The literal meaning of glycocalyxes is “sugar cup.” It is made up of polysaccharides and polypeptides. It protects the cell from drying. Glycocalyxes of the pathogenic bacteria plays a vital role in the cell’s survival and disease causal. Sticky nature of the glycocalyx helps bacteria to attach the surfaces. Hence, this option is incorrect.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 10SA
Any chemical reactions that are involved in maintaining the living state of the cell is known as metabolism. It controls the chemical reactions in an organism and cellular structure.
It is a unique process of living things. Non living things cannot metabolize. Metabolic energy is stored in the chemical bonds of the adenosine triphosphate (ATP).
It is divided in to two categories, anabolism and catabolism. Catabolism is defined as break down of molecules to obtain energy. Synthesis of all compounds needed by cell is known as anabolism.
Metabolism results in growth and development of living cells.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 11MC
(a) The bacterial cell wall of gram positive contain thick layer of peptidoglycan. It also contains a chemical known as teichoic acid, which helps in the passage of ions through the cell wall.
Gram negative bacteria cell wall contains a thin layer of peptidoglycan and outer membrane composed of phospholipids and proteins. Outer leaflet is composed by lipopolysaccharides. Thus, the given option, exterior of the cell is negative, when compared to the interior is false. Hence, the option (a) is incorrect.
(b) Gram negative bacteria cell wall contain thin layer of peptidoglycan and outer membrane composed of phospholipids and proteins. Outer leaflet is composed by lipopolysaccharides.
Gram negative bacteria have periplasmic space between outer membrane and cytoplasm. Periplasmic space consists of water, nutrients and cell secreted substances like proteins and digestive enzymes, which involves active transport. Thus, by means of facilitated diffusion the acid move is the wrong statement. Hence, the option (b) is incorrect.
(d) Gram negative bacteria cell wall contains a thin layer of peptidoglycan and outer membrane composed of phospholipids and proteins. Outer leaflet is composed by lipopolysaccharides. Gram negative bacteria have periplasmic space between outer membrane and cytoplasm.
Periplasmic space consists of water, nutrients and cell secreted substances like digestive enzymes and proteins which are involved in active transport. Phagocytosis involves the movement of the acid is false statement. Hence, this option (d) is incorrect.
(e) Gram negative bacteria cell wall contains a thin layer of peptidoglycan and outer membrane composed of phospholipids and proteins. Outer leaflet is composed by lipopolysaccharides. Gram negative bacteria have periplasmic space between outer membrane and cytoplasm.Periplasmic space consists of water, nutrients, and cell secreted substances like proteins and digestive enzymes, which involves active transport. Hence, this option (c) is correct.
Hence, the correct answer is (c) The acid moves by the active process such as active transport.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 11SA

  • The most important structures that are used for the motility of bacteria are known as flagella.
  • Flagella are mainly used to move towards food or light. They are long structures, which extend beyond the surface of the cell. It senses the external wetness and inhibiting their growth in dry habitats.
  • Bacterial flagellum is composed of protein known as flagellin. They are made up of three parts; filament, hook and basal body. Filament is long and thin, it about 20nm in diameter.
  • Hook and basal body are composed of different proteins. The hook, rod and rings allow the filament to rotate 3600.
  • Flagella that are spread across the surface of the cell are known as peritrichous and flagella arrange only at ends are known as polar flagella.
  • Bacterial flagella rotate more than 100,000 rpm and the direction can change from counter clockwise to clock wise direction. Flagella have receptors, which gives signals to flagella to adjust their speed and direction of rotation.
  • The flagella movement in response to stimulus is known as taxis. Light stimulus is known as phototaxis and chemical stimulus is known as chemotaxis.
  • Eukaryotic flagella differs in structure and function from prokaryotic flagella. They attach within the cytoplasmic membrane. Their internal structures push cytoplasmic membrane out around them.
  • Eukaryotic flagella are mainly composed of globular protein known as tubulin.This tubulin is arranged in chains to form hollow micro tubules.
  • Nine pairs of the micro tubulins are surrounded by the two micro tubules in the center. This 9+2 arrangement of micro tubulins is present in all flagellated eukaryotic cells.
  • Eukaryotic flagella may be single or multiple and found at one pole of the cell. Comparative to prokaryotic flagella they move differently. They have both positive and negative phototaxis and chemotaxis.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 12MC
Gram-positive bacteria have thick cell wall, which contains teichoic acids. In gram staining procedure cell wall retains crystal violet dye, so they appear purple color.
(a) Have a thick cell wall, which retains crystal violet:
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. It also resists antimicrobial drugs, which plays an important role in treatment of bacterial diseases with specific antibiotics. Bacterial cell walls are composed of peptidoglycan. Peptidoglycan is a complex polysaccharide and is composed of two types of sugar molecules, N-acetyl muramic acid and (NAM) N-acetyl glucosamine (NAG). In addition, the sugar molecules, NAG and NAM are covalently connected by chains, to join four amino acid residues to cover the total surface of the cell.
Moreover, thick layer of peptidoglycan is present in Gram positive bacterial cell wall. It also contains a chemical known as teichoic acid, which helps in the passage of ions through the cell wall. In gram staining procedure cell wall retains crystal violet dye, so they appear as purple color. Hence, the option (a) is correct.
(b) Contain teichoic acids in their cell walls:
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. It also resists antimicrobial drugs. It plays an important role in treatment of bacterial diseases with specific antibiotics. Bacterial cell walls are composed of peptidoglycan.
Moreover, thick layer of peptidoglycan is present in Gram positive bacterial cell wall. It also contains a chemical known as teichoic acid which helps in the passage of ions through the cell wall. Hence, the (b) option is correct.
(c) Appear purple after staining:
Bacterial cell wall gives structure and shape to the cell and protects from osmotic forces. It also resists antimicrobial drugs. It plays an important role in treatment of bacterial diseases with specific antibiotics. Bacterial cell walls are composed of peptidoglycan.Moreover, thick layer of peptidoglycan is present in Gram positive bacterial cell wall. It also contains a chemical known as teichoic acid, which helps in the passage of ions through cell wall. In gram staining procedure cell wall retains crystal violet dye, so they appear as purple color. Hence, the option (c) is correct.
Hence, the correct answer is (d) all of the above.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 12SA
All cells are described as either prokaryotes or eukaryotes. Prokaryotes are characterized in to two taxa they are Domain Archaea and Domain bacteria. Algae, protozoa, fungi animals and plants are eukaryotes.
microbiology-with-diseases-by-taxonomy-chapter-3-answers-12sa

Microbiology with Diseases by Taxonomy Chapter 3 Answers 13MC
When nutrients and water get exhausted, gram positive bacteria form a unique structure known as endospores. They are dormant and resistant cells. They are viable, for over hundred years. They are highly durable and dehydration resisting bodies.
(a) When nutrients and water get exhausted, gram positive bacteria form a unique structure known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable for over hundred years. They are highly durable and dehydration resisting bodies. They have thick walls of peptidoglycan, DNA cells, and cytoplasm. They contain large quantities of dipicolinic acid, calcium, and DNA binding proteins. They are not reproductive structures. Hence, the option (a) is incorrect.
(b) When nutrients and water get exhausted, gram positive bacteria form a unique structure known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable for over hundred years. They are highly durable and dehydration resisting bodies. They are not produced by archaeal. Hence, the option (b) is incorrect.
(c) When nutrients and water get exhausted, gram positive bacteria form a unique structure known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable for over hundred years. They are highly durable and dehydration resisting bodies.
The process of endospores formation is known as sporulation. They are resistant to drying, heat radiation, and lethal chemicals. Endospores stay alive in water even when boiled for several hours. They produce deadly toxins that cause fatal diseases like anthrax and tetanus. Hence, the option (c) is incorrect.
(d) When nutrients and water get exhausted, gram positive bacteria form unique structures known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable for over hundred years. They are highly durable and dehydration resisting bodies. They have thick walls of peptidoglycan, DNA cells, and cytoplasm. They contain large quantities of dipicolinic acid, calcium and DNA binding proteins
Hence, the correct option is (d) endospores are dormant, resistant cells.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 13SA

  • Fimbriae are rod like proteinaceous extensions in bacteria. Fimbriae are short, numerous, nonmotile structures, that are sticky and bristle like projections.
  • Bacterial cell may contain hundreds of fimbriae. They are thinner and shorter than flagella. They are clearly seen under electron microscope.
  • They are mainly useful for bacteria to attach surface. Fimbriae are located in either poles of a cell or spread total surface of the cell, and are mainly found in gram negative bacteria.
  • Fimbriae and glycocalyx play important role in the formation of biofilms. Biofilms are slimy masses of microbes adhering to a substance by means of fimbriae and glycocalyx.
  • Fimbriae act as electrical wires that conduct electrical signals among cells in the biofilms. Biofilms play important role in the human diseases and in industry.
  • Bacteria in biofilms are communicated with chemicals and electrical signals, which help them to form 3-dimentional structure. Biofilms also increase the bacterial resistance to antibiotics. They cause bacterial infection in humans; examples are gum disease and serious lung infections.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 14MC
(a) DNA:
DNA(deoxyribonucleic acid) is a genetic material in almost all living organisms. Most of the DNA viruses are double stranded. The bases of the DNA are adenine guanine, cytosine and thymine. It contains millions of nucleotides. Moreover, it is found in chromosomes, mitochondria, and chloroplast. Hence, the option (a) is incorrect.
(c) Dipicolinic acid:
When nutrients and water get exhausted, gram positive bacteria form a unique structure known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable, for over hundred years. They are highly durable and dehydration resisting bodies. They have thick walls of peptidoglycan, DNA, and cytoplasm. They contain large quantities of dipicolinic acid, calcium, and DNA binding proteins. Hence, the option (c) is incorrect..
(d) Tubulins:
Eukaryotic flagella are mainly present in the globular protein, known as tubulin. This tubulin is arranged in chains to form hollow micro tubules. Nine pairs of the micro tubulins are surrounded by the two micro tubules in the center. The 9+2 arrangement of micro tubulins is present in all flagellated eukaryotic cells. Hence, the option (d) is incorrect.
(b) Sulfur globules:
Sulfur globules are the inclusions, found in the bacterial cytosol. They include reserve deposits of starch, lipids, and compounds containing nitrogen, phosphate, and sulfur. These chemicals are stored in cytosol. Presence of inclusions helps in the diagnosis of pathogenic bacteria. Most of the bacteria store carbon and energy in the form of glycogen molecules or lipid polymer called polyhydroxybutyrate. The inclusions present in the cyanobacteria store gases in protein sacs known as gas vesicles.
Hence, the correct option is (b) Sulfur globules.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 14SA

  • The membrane present below the glycocalyx and the cell wall is known as cytoplasmic membrane. It is also known as cell membrane or plasma membrane.
  • Thickness of cytoplasmic membrane is 8 nm and it is composed of phospholipids and proteins.
  • Cytoplasmic membrane structure is referred to as phospholipid bilayer. Phospholipid molecule is bipolar.
  • The phospholipid molecule that is attracted by water is known to have hydrophilic nature and the phospholipid molecule, which will be repelled by water, is known to have hydrophobic nature.
  • Cytoplasmic membrane of bacteria is composed of integral proteins. Peripheral proteins are attached loosely to the membrane on one or another side.
  • Cell membrane proteins act as recognition proteins, enzymes, receptors, and as carries.Cell membrane prevents the passage of substances into and out of the cell.
  • It allows nutrients into the cell and sends wastes out of it. It also involves in synthesis of molecules for energy storage and harvest light energy in photosynthetic bacteria.
  • The membrane is selectively permeable and allows only some substances to cross it. It prevents the crossing of other molecules.
  • The two main factors that prevent a molecule from moving across a cell membrane are size and composition. Large molecules cannot move across the cell membranes.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 15MC
(a) Gram positive archaeal walls:
Archaeal gram positive have thick cell wall similar to gram positive bacteria. In gram staining procedure, cell wall retains crystal violet dye, so they appear in purple color. Hence, the option (a) is incorrect.
(b) Cytoplasmic membranes in eukaryotes:
Eukaryotic cytoplasm consists of fluid mosaic model of phospholipids and proteins. These membranes contain sterols like cholesterol that helps in strengthening and solidifying, when temperature rise and provide fluidity during the fall in temperature. Hence, the option (b) is incorrect.
(c) Golgi bodies:
Golgi body is a shipping department of the cell. It receives and packs large molecules, for export from the cell. The secretions of Golgi body packages are known as secretory vesicles. Golgi bodies are made up of flattened hollow sacs, which are circumscribed by a phospholipid bilayer. Hence, the option (d) is incorrect.
(d) Endospores:
When nutrients and water get exhausted, gram positive bacteria form unique structure known as endospores. For example, bacillus and clostridium produce endospores. Endospores are dormant and resistant cells. They are viable for over hundred years. They are highly durable and dehydration resisting bodies. They have thick walls of peptidoglycan, DNA (deoxyribonucleic acid), and cytoplasm. They contain large quantities of dipicolinic acid, calcium, and DNA binding proteins. Hence, the option (c) is incorrect.
Hence, the correct answer is (c) Endospores.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 15SA

  • Passive transport does not utilize the energy from cell. The electro chemical gradient provides energy for passive transport. It includes diffusion, facilitated diffusion, and osmosis.
  • The net movement of a chemical from high concentration area to low concentration area is known as diffusion.
  • It does not require energy from the cell. This process can occur even when there are no cells and cell membranes.
    Only small sized and lipid soluble chemicals can diffuse through the phospholipid membrane.
    For example, oxygen, carbon dioxide, alcohol, and fatty acids can diffuse freely via phospholipid membrane, whereas molecules like proteins and glucose cannot diffuse.
  • Diffusion is very important process in cell. It brings nutrient and also removes (without spending energy) wastes from the cell. Its main function is to move molecules in or out of the cell.
  • Specific molecules can cross the cell membrane through protein channels by a process known as facilitated diffusion. It occurs by means of carrier protein.
  • Facilitated diffusion does not utilize the energy present in the cell; instead, it obtains energy from the electrochemical gradient process. Some protein channels allow the passage of chemicals.
  • It is also known as passive mediated transport. It allows passage of molecules and ions spontaneously across biological membranes.
  • It mainly occurs either in biological membrane or aqueous compartment in organism.Passive transport is example for facilitated diffusion. Its main function is movement of sugars and amino acids through the cell membrane.
  • The diffusion of water molecules through a semi-permeable membrane is known as osmosis. The semi permeable membrane allows only water; it does not allow the passage of ions and molecules (solute particles).
  • Osmosis diffuses water from high concentration area to low concentration area.
  • When the solutions present on either side of a selectively permeable have same concentration then those solutions are said to be isotonic.
  • When the concentration of solutions is not equal, then the solution containing higher concentration of solutes is known as hypertonic.
  • The solution having lower concentration of solutes is known as hypotonic. Water molecules move based on the concentration gradient, that is, hypotonic solution towards hypertonic solution.
  • It plays important role in cell because it keeps cell alive. It keeps cells from lysing or shrinking. It distributes nutrients and allows release of metabolic wastes from the cell.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 16SA
Active transport is a process of transporting molecules across the cell membrane. It uses transmembrane permease proteins. Some of these proteins are called gated channels (ports). When cell needs substance then the proteins start functioning and open the gated channels; at normal time, these channels are closed.
The permease, which transports only one substance at a time, is known as uniport permease. It is named antiport permease, if a permease moves two substances in opposite direction that means one substance is transported into the cell, while another substance is transported out of the cell. Symports are single carrier proteins that transport two substances at-a-time in one direction through the membrane.
Group translocation is an active process and it takes place only in few bacteria. In this process, substances are transported actively across the membrane and are chemically changed. The membrane traps the substances inside the cell.
It is very efficient in bringing the substances into the cell. It also operate the external concentration of the chemicals that transport as low as one part per million (ppm). Fatty acids, carbohydrates, pyrimidines, and purines are transported into the bacterial cells through group translocation.
Endocytosis is a type of active transport, in which physical manipulation of cytoplasmic membrane around the cytoskeleton involved. This happens when the membrane expand to form pseudopodia, surrounding the substance to bring it inside the cell.
When any solid substance is brought into the cell through this process, it is termed phagocytosis and if any liquid substance is brought into the cell by this process, it is termed pinocytosis.
Exocytosis is a eukaryotic process, which is reverse to the endocytosis. It enables the substance to be exported from the cell.
Their vesicles contain substances fused with cytoplasmic membrane, dumping their contents to the outer side. They transport substances like wastes and secretions.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 17SA

  • Active transport is a process of transporting molecules across the cell membrane using transmembrane permease proteins.
  • Some of these proteins are called gated channels (ports). When cell needs substance these proteins start functioning and open the gated channels; at normal time, these channels are closed.
  • The permease, which transports only one substance at a time, is known as uniport permease. It is named antiport permease, if a permease moves two substances in opposite direction that means one substance is transported into the cell, while another substance is transported out of the cell.
  • Symports are single carrier proteins that transport two substances at-a-time in one direction through the membrane.
  • The electro chemical gradient provides the energy needed for this transport. In this type of transport, both symport and antiport work at the same time and is known as coupled transport.
    For example, H+ ions move down its electro chemical gradient by facilitated diffusion and provide energy to transport glucose into the cell against the gradient.

Microbiology with Diseases by Taxonomy Chapter 3 Answers 18SA
Mitochondria and chloroplast are semi-autonomous, that is, they divide independently, but they depend on the cell for proteins. They contain small amounts of DNA (deoxyribonucleic acid) and 70S ribosomes. They synthesize polypeptides using ribosomes.
In 1938, Lynn Margulis proposed a theory known as endosymbiotic theory for formation of eukaryotic cells. Based on this theory, parasites loss their ability to exit independently, but they retained DNA, ribosomes, and cytoplasmic membranes. At the same time, the larger cells became dependent on the parasites for aerobic ATP (adenosine triphosphate) production.
Based on this theory, aerobic prokaryotes changed into mitochondria and their cytoplasmic membranes become cristae. This theory explains the presence of 70S ribosomes and circular DNA within mitochondria and chloroplasts.
This theory was not accepted by the universe because it did not explain the two membranes of nuclear envelope.

 

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