Frank ICSE Class 9 Biology Solutions – Light

Frank ICSE Solutions for Class 9 Biology – Diversity of Life and Classification

PAGE NO:117

Solution 1:
Diversity refers to the variety of living organisms found within a given ecosystem, biome, or on an entire planet.

Solution 2:
The method of arranging organisms into series of groups on the basis of similarities and differences is called classification.
Classification is important in the following ways:

1.  It makes the study of a wide variety of organisms easy.
2.  It gives us an overall picture of all the life-forms.
3. It helps us to understand the interrelationships among different groups of organisms.
4. It forms a base for the development of other biological sciences.

Solution 3:

Solution 4:
Taxonomy is the study of the theory, practice and rules of classification of living and extinct organisms.

Solution 5:
The five kingdom system of classification was proposed by R. H. Whittaker in 1969. This classification is based on the following four facts:

• Complexity of cell structure
•  Methods of nutrition (autotrophic or heterotrophic)
• Complexity of body organization.
•  Phylogenetic relationships.

The five kingdoms in this system are:

1. Monera – It includes all the prokaryotes like bacteria and cyanobacteria. They are important decomposers.
2.  Protista – It includes the aquatic, eukaryotic, acellular organisms like protozoans.
3. Fungi – This kingdom includes moulds, mushrooms and yeasts.
4. Plantae – It includes all the coloured, multicellular, eukaryotes with cell walls.
5.  Animalia – These are multicellular eukaryotes lacking cell wall and showing heterotrophic nutrition.

Solution 6:
Important characters of five kingdom are:
 Characters of kingdom Monera are:

1. It contains acellular organisms, ranging in size between 0.15  to 2.0 .
2.  They are prokaryotes, lacking a well-defined nucleus .
3. They usually lack chlorophyll and hence are parasites or saprophytes.
4. Reproduction occurs by binary fission or budding in bacteria.
   Example – Actinomycetes, bacteria, cyanobacteria.

Characters of kingdom Protista are:

1.  They are aquatic, unicellular organisms.
2. They have eukaryotic cells with well-defined nucleus and organelles.
3. They show autotrophic or heterotrophic mode of nutrition.
4. Some protists are parasites and few are decomposers too.
   Example – Euglena, Ameoba, Paramoecium.

 Characters of kingdom Fungi:

1.  They may be unicellular or multicellular.
2. They have heterotrophic nutrition and mostly they are saprophytes.
3. Their body is made up of mycelium, a filament of which is called hypha.
4.  Their cell wall is made up of chitin.
   Example – Aspergillus, Agaricus, Penicillium.

 Characters of kingdom Plantae:

1. They are multicellular, eukaryotic organisms.
2.  The cell membrane is surrounded by a thick cell wall of cellulose.
3. Except a few aquatic life forms, plants are non-motile.
4.  They have different modes of nutrition: autotrophic, parasitic even
   insectivorous.
   Example – Mango, Cycas, Fern, Moss.

 Characters of kingdom Animalia:

1.  They are multicellular, eukaryotic organisms without cell wall.
2. They show heterotrophic mode of nutrition.
3. They can retract or expand with the help of muscles.
4.  They are consumers in-between producers and decomposers.
   Example – Fish, Frog, Earthworm, Man.

Solution 7:
The kingdom Plantae has been divided into following groups:
Thallophyta 

•  They are consists of red, green and brown algae.
•  Algae are of universal occurrence.
•  Their body ranges from unicellular to multicellular colonies, filaments or sheets of cells.
• Vascular tissues are absent.
•  Nutrition is generally autotrophic (through photosynthesis).
• Reproduction is vegetative or sexual.

 Bryophyta

•  It consists of liverworts and mosses.
• They are terrestrial, found in damp, shady places.
•  Their life cycle has a long gametophytic phase and a short sporophytic phase.
• Liverworts have prostrate thalloid gametophytic body, but mosses have erect body.
• True roots are absent, but rhizoids presents.
•  Vascular tissues are absent.
•  Nutrition is generally autotrophic (through photosynthesis).
•  Reproduction is vegetative or sexual.

 Pteridophyta 

• They include ferns, horse-tails and club mosses.
• They occur mainly in cool, shady and moist places.
• They are mostly terrestrial.
• They are perennial herbs with stem in the form of rhizome.
•  Fibrous roots present.
• Their life cycle has a gametophytic phase and a short sporophytic phase.
•  Vascular tissues are present.
•  Nutrition is generally autotrophic (through photosynthesis).
•  Reproduction is vegetative or sexual.

 Spermatophyta 

•  They are the most successful terrestrial plants having seeds.
•  They produce seeds (fertilized ovules).
• They are divided into two groups –

1.  Gymnosperms -They bear naked seeds and lack flowers.
   Examples: Pine, Cycas
2. Angiosperms – They produce seeds enclosed in ovary and flowers
   are present.
   Examples: Rose, Grass

Solution 8:

Solution 9:

Solution 10:
The various classes of Chordata are:

1. Pisces – Labeo (Rohu), Scoliodon (Dog fish)
2. Amphibia – Rana (Frog), Hyla (Tree frog )
3.  Reptilia – Kanchuga (Tortoise), Naja naja ( Cobra)
4.  Aves – Columba (Pigeon), Pavo (Peacock)
5. Mammalia – Elephas ( Elephant), Funambulas (Squirrel)

Solution 11:

Solution 12:
Characters of mammals are:

1. The females of this class are provided with mammary glands which produces milk to feed the young one.
2. Body usually covered with hair, spines, scales, nail, hoof or horn.
3.  External ear or pinna is well-developed.
4. They are warm-blooded.

PAGE NO:118

Solution 13:
(a) Starfish belongs to phylum Echinodermata.
Two characters of starfish are:

1. Spines found on the body which is covered by calcareous plates.
2.  Body is star shaped with five radiating areas called ambulacra with inter-ambulacra in between.

(b) Whale belongs to phylum Chordata.
Two characters of whale are:

1. They are warm blooded marine animals.
2. Heart is completely four-chambered.

(c) Jelly fish belongs to phylum Coelenterata.
Two characters of jelly fish are:

1.  Body diploblastic having outer epidermis and inner gastrodermis with gelatinous mesoglea.
2. Tentacles are present around the mouth.

(d) Cockroach belongs to phylum Arthropoda.
Two characters of cockroach are:

1.  They have jointed legs.
2. Their exoskeleton is made up of chitinous cuticle which is shed from time to time.

Solution 14:

Solution 15:
Bryophyta – Liverwort and Moss.
Pteridophyta – Fern and Horsetail.

Solution 16:
Antedon (Sea lily) and Asterias (Star fish ).

Solution 17:
Whale

Solution 18:
Cockroach, crab

Solution 19:
Frog

Solution 20:
Echidna

Solution 21:
Earthworm – Pheretima posthuma and
Roundworm – Ascaris

Solution 22:

Solution 23:
(a) Arthropoda
(b) Porifera
(c) Mollusca

Solution 24:
(a) Protozoa
(b) Mollusca
(c) Annelida

Solution 25:
(a) Asterias (Star fish ), Echinus (Sea-urchin)
(b) Scoliodon (Dog fish), Labeo (Rohu)
(c) Fasciola ( Liver fluke), Taenia solium (Tapeworm)
(d) Ascaris ( Roundworm), Wuchereria (Filarial worm )
(e) Pheretima (Earthworm), Hirudinaria ( Leech )
(f) Palemon (Prawn), Periplaneta (Cockroach)

Solution 26:
(a) Annelida
(b) Coelenterata
(c) Arthropoda
(d) Echinodermata

Solution 27:
(a) Flame cells
(b) Nemathelminthes
(c) Annelida
(d) Porifera
(e) Chordata

Solution 28:

1. (a) three pairs of legs are present.
2. (a) coelentrata
3. (c) octopus
4. (c) paramoecium
5. (c) hippocampus
6. (a) Scorpion
7. (b) for five kingdom classification
8.  (a) prokaryotic and multicellular eukaryotic cell
9.  (d) plant
10. (d) C. Linnaeus
11. (c) Carolus Linnaeus

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Frank ICSE Solutions for Class 9 Biology – Bacteria and Fungi Their Importance

PAGE NO:127

Solution 1:

1.  Bacteria are a large group of unicellular, prokaryotic microorganisms.
2.  The bacteria which do not get stained with crystal violet and iodine solution are called gram negative bacteria while those bacteria which get stained with crystal violet and iodine solution are called gram positive bacteria.

Solution 2:

1. Bacteria shows the presence of cell wall, hence they are included under plants.
2.  Spore formation helps bacteria to survive during adverse environmental conditions. Hence it is a survival technique.
3.  Bacteria as friends :
   Bacteria are useful to us in many ways like producing antibiotics, forming curd and cheese, tanning leather, producing various industrial products, nitrogen fixation, digesting cellulose etc.
   Bacteria as foes:
   They are harmful in many ways like causing diseases, bio-weapons , food spoilage etc.
4. Yeast is used in breweries since the fermentation activity of yeast produces different types of beverages like wine, beer, alcohol toddy etc. In bakeries, when yeast is added to the flour its fermentation results in the production of carbon dioxide which produces soft bread and other bakery products.

Solution 3:

Solution 4:

Solution 5:

PAGE NO:128

Solution 6:

Solution 7:
(a) Penicillium notatum
(b) Aspergillus fumigatus
(c) Candida albicans
(d) Aspergillus

Solution 8:
(a) chitin
(b) saprophytic
(c) obligate aerobes
(d) Agaricus campestris

Solution 9:

Solution 10:
Fungi are cooked like vegetables or used in pulao or prepared as soups. Some common edible fungi are Agaricus, Ramaria, Clavaria, Morchella.
Also yeast is used in preparing idli and dosa from a mixture of powdered rice and dal.

Solution 11:
Yes. Many types of antibiotics are obtained from fungi which are used in medical sciences. Today about 25 types of antibiotics are commercially produced from moulds.
For example: Penicillin is obtained from the fungus Penicillium notatum.
Griseofulvin is extracted from the fungus Penicillium griseofulvum.

Solution 12:

Solution 13:

1. (b) Leeuwenhoek
2. (a) bacteria
3. (b) Bacillus
4. (a) Tuberculosis
5. (d) Rhizobium
6. (b) Lactobacillus
7. (d) Agaricus
8.  (a) ethyl alcohol

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Frank ICSE Solutions for Class 9 Biology – Nutrition in Man

PAGE NO:138

Solution 1:
Carbohydrates provide energy and warmth to our body.

Solution 2:
Sources of Vitamin C are Lemon and carrot and sources of Vitamin A are Green vegetables and egg yolk.

Solution 3:
Vitamin C

Solution 4:
Pigs and crows

Solution 5:
Carbohydrates

Solution 6:
Roughage

Solution 7:
Assimilation

Solution 8:
Fats

Solution 9:

1. Carnivores are flesh-eating animals that eat other animals. Example – Snakes, Lion, tiger, vulture
2. Omnivores are animals that feed on both animals and plants. Example – crows, certain bears.
3.  Scavenger is any animal that feeds on refuse and other decaying organic matter. Example – vultures, dung beetle.

Solution 10:

Solution 11:
Food is a mixture of nutritive substances which when taken and incorporated into the body tissues provide materials for energy, repair, growth, reproduction, regulation of life processes and resistance to diseases.

Solution 12:
Proteins are used in the synthesis of new protoplasm to be utilized in growth and tissue repair. Hence they are called body building foods.

Solution 13:
(a) Night-blindness
(b) Protein
(c) Vitamin D
(d) Insectivore

Solution 14:
(a) False
(b) True
(c) True
(d) False
(e) True

PAGE NO:139

Solution 15:
Water is necessary for our body because:

1.  Water acts as solvent for many organic and inorganic compounds
2.  Water facilitates the movement of food materials, waste products and other chemical substances in the cytoplasm and circulatory process.
3.  It plays an important role in regulating body temperature and osmotic pressure of the body fluids.
4.  Water serves as good medium for various metabolic reactions.

Solution 16:
The undigested fibrous material present in the food is called roughage. Raw vegetables, and bran are examples of roughage

Solution 17:
(a) energy
(b) glycogen
(c) fatty acid, glycerol
(d) sucrose, maltose

Solution 18:

1. The condition where people become weak and sick due to insufficient and unbalanced diet is referred to as malnutrition.
2.  Saprozoic nutrition refers to nutrition in which animals feed on dead or decaying matter.
3. Vitamins are organic compounds regularly required in minute quantities in the diet for normal metabolism, health and growth.

Solution 19:
(a) Milk
(b) Sugarcane
(c) Plants
(d) Yellow and green vegetables

Solution 20:

1. Kwashiorkor develops in children whose diet is deficient in proteins even if sufficient carbohydrates and fats are consumed. This disease is common among infants and children up to 3 years old. The symptoms of Kwashiorkor include reduced body weight, slurred growth, protruding belly and thin legs.
2.  Marasmus is a form of prolonged protein energy malnutrition. It affects infants under one year of age. The symptoms of Marasmus include irreversible muscle degeneration, dry, wrinkled skin, prominent ribs and thin legs.

Solution 21:

1.  Deficiency of iron leads to anaemia.
2.  Deficiency of iodine leads to goitre.

Solution 22:

1. (a) 500 gm
2. (d) food
3. (b) rice
4. (b) Carrot
5. (a) A, D and E
6. (d) K
7. (c) Protein
8. (a) C

Frank ICSE Solutions for Class 9 Biology – Digestive System

PAGE NO:151

Solution 1:
Nutrition can be defined as the process which involves the utilization of food by an animal to obtain energy for growth and development. There are two types of nutrition – autotrophic and heterotrophic.

Solution 2:

1.  Autotrophs: These are the organisms which prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc. Example – green plants and certain protests.
2. Heterotrophs: The organisms which cannot prepare their own food and depends on ready-made food synthesized by green plants are called heterotrophs. Examples – animals and human beings.
3. Carnivores: The organisms which feed upon other animals and animal products. Examples – tiger, lion, cat, etc.
4. Omnivores: The organisms which feed on all kinds of plant and animal food are called omnivores. Examples – Cockroach and human beings.
5. Herbivores: The organisms that feed on plants only are termed as herbivores. Examples – sheep, cow, goat, etc.

Solution 3:

1.  Parasites are the organisms that live in or on the body of another organism called host, and obtain nourishment from its body whereas saprophyte is an organism that absorbs soluble organic nutrients from dead and decaying organic matter.
2. Autotroph is an organism which prepares organic food in their body from simple inorganic materials like carbon dioxide, water, etc. whereas heterotroph is an organism which cannot prepare its own food and depends on ready-made food synthesized by green plants.
3. Holozoic nutrition is a nutrition in which animals survive by consuming other organisms whereas saprozoic nutrition is the nutrition in which the animals absorbs soluble organic nutrients from dead and decaying organic matter.
4.  Holophytic nutrition is the nutrition in which organisms prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc. whereas in holozoic nutrition, the animals survive by consuming other organisms.

Solution 4:
The steps involved in animal nutrition are:

1. Ingestion – It means taking solid or liquid food inside the body.
2. Digestion – It is the breaking down of complex insoluble food components into simple soluble substances.
3.  Absorption – It is the process by which soluble soluble digested food passes from alimentary canal into blood and lymph through intestinal villi.
4. Assimilation – Utilization of absorbed food by different body cells is called assimilation.
5.  Egestion – Elimination of undigested food as faeces is called egestion.

Solution 5:
There are four types of teeth:

1. Incisors – These are used for cutting.
2.  Canines – These teeth are used for tearing.
3.  Premolars – For masticating the food.
4. Molars – For grinding and masticating the food.

Solution 6:

Solution 7:

Solution 8:
(a) False
(b) False
(c) True
(d) False

Solution 9:

Solution 10:

Solution 11:

Solution 12:
Salivary Glands – Three pairs in man and secrete 1000 to 1500 cc saliva per day.
Saliva is slightly acidic and its pH is 6.8.
There are three types of salivary glands:

1.  Parotid glands: It is the largest salivary gland and situated near the ears. It opens into oral cavity by Stenoson’s duct.
2.  Sublingual glands: It is located beneath the tongue. It opens into the floor of oral cavity by duct of Rivinus.
3.  Submadibular or sub-maxillary glands: It is situated at the angles of the lower jaws. It opens inot oral cavity by Whartson’s duct.
   Each gland secret secretes saliva which is transported to the mouth cavity. At the time secrete saliva.

Solution 13:
(a) Lipase
(b) Lungs
(c) Rectum

Solution 14:

Solution 15:

Solution 16:

Solution 17:
(a) Carboxypeptidase
(b) Rennin
(c) Caecum
(d) HCl
(e) Pepsin
(f) Digestion
(g) Protein
(h) Bilirubin

Solution 18:

Solution 19:

1. Stomach – Pepsin
2. Salivary glands – Salivary amylase/Ptyalin
3. Pancreas – Trypsin, Chymotrypsin, Carboxy peptidase, Pancreatic amylase and Pancreatic lipase.
4.  Ileum – Enterokinase, Endokinase, Aminopeptidase and Dipeptidase.

Solution 20:

Frank ICSE Solutions for Class 9 Biology – The Skeletal System

PAGE NO:162

Solution 1:
Bones of skull, vertebral column, sternum and ribs.

Solution 2:
Longest bone – Femur
Smallest bone – Stapes of middle ear.

Solution 3:
There are seven cervical vertebrae. First vertebra is called atlas, second is axis while the rest are called typical cervical vertebrae.

Solution 4:
The skeletal system performs the following functions in an animal:

1.  It provides a framework to support the body and gives a definite shape and form to the body.
2.  It helps to protect some of the vital organs like heart, lungs, brain and spinal cord.
3. It provides the base for attachment of muscles and several bones so as to make body movements possible.
4. Bones act as storehouse of some minerals like calcium and phosphorus.
5. Red bone marrow of long bones of limbs produces red blood cells and granulated white blood cells in their hollow cavities.

Solution 5:

1. Axial skeleton
2.  Appendicular skeleton

Solution 6:
The various parts of a human skeleton are:

1. Axial skeleton: This consists of skull, vertebral column, sternum and ribs
2. Appendicular skeleton: It consists of pectoral and pelvic girdles and bones of limbs.

Solution 7:

Solution 8:
On the basis of position, endoskeleton is divided into two main parts:

 Axial skeleton: This consists of skull, vertebral column, sternum and ribs. Human skull has 22 bones of which 8 are present in the cranium and 14 on the face. Brain is present in the cavity called cranium. In the occipital region is an opening called foramen magnum through which spinal cord passes. Cranium has 8 bones which covers the brain from all sides.
 Facial bones: These bones form the face and protect the sensory organs present in the head. It has 14 bones.
Vertebral Column:
It makes the axis of the body and provides support like a pillar. Vertebral column is divided into following five parts:

1.  Cervical Region. It has 7 cervical vertebrae. First vertebra is called atlas, second is axis and rest are called typical cervical vertebrae.
2.  Thoracic Region. It has 12 thoracic vertebrae. Neural spine of these vertebrae is long and pointed, which provdes surface for muscle and attachment.
3. Lumber Region. It has 5 lumber vertebrae.
4.  Sacral Region. It has 5 sacral vertebrae which are permanently fused to each other. These are situated on both halves of pelvic and form a joint with pelvic girdle.
5.  Caudal Region. It has 4 caudal vertebrae. These are also fused to form a triangular structure which is called coccyx.

Sternum and Ribs
Sternum is the bone at the mid-ventral line of the thorax to which most of the ribs are attached at their ventral ends. Ribs are formed by vertebral and sterna part. First seven pairs of ribs are called true ribs. These are joined on one side with sternum and on second side with thorax.
Appendicular skeleton: It consists of limbs, shoulder or pectoral girdle and hip or pelvic girdles and bones of limbs.

1. Bones of the fore arm: Humerus, radius, Ulna, Carpals, Metacarpals, finger bones, etc.
2.  Bones of hind limb: Femur, Tibia, Fibula, Tarsal, Metatarsal, etc.
3.  Pectoral Girdle: In mammals, two halves of pectoral girdle are situated at equal distance from the ribs on the dorsal plane. Each of it is called shoulder bones. Each half of it made up of a triangular flat bone called scapula. From its outer side a projection arises called acromion and has a cavity called glenoid cavity.
4.  Pelvic Girdle: It consists of two similar halves. In each, three bones are found, ilium, ischium and pubis. Pubis bones of both halves are joined and are called pubic sysmphysis. Ilium and ischium form acetabulum cavity in which head of femur articulates by forming ball and socket joint. A hollow space is found between pubis and ischium, which is called obdurate foramen, which provides passage for obturatry artery, vein and nerve.

Solution 9:

Solution 10:

Solution 11:
Importance of pectoral girdle:

1. It provides support to the anterior portion of the body.
2.  Provides surface articulation of fore arms.
3.  Provides surface for muscle attachment.
4.  Provides protection to vital organs like heart and lungs.

Importance of pelvic girdle:

1. Provides surface articulation of hind limbs.
2. Provides surface for joining of muscles.
3.  Provides protection to the uterus.
4. Protects from shocks.

Solution 12:
The place of joining of two or more than two bones is called joint.

Solution 13:
Flexor is a muscle that causes bending of a limb or other part e.g. thigh muscle.
Extensor is the muscle that causes the straightening of a limb or other part. E.g. for extending the foot
Levator is the muscle that raises any part of the body.
Rotator is a muscle that rotates one part on another.

Solution 14:
Axial skeleton: This consists of skull, vertebral column, sternum and ribs. Human skull has 22 bones of which 8 are present in the cranium and 14 on the face. Brain is present in the cavity called cranium. In the occipital region is an opening called foramen magnum through which spinal cord passes. Cranium has 8 bones which covers the brain from all sides.
Facial bones: These bones form the face and protect the sensory organs present in the head. It has 14 bones.
Vertebral Column:
It makes the axis of the body and provides support like a pillar. Vertebral column is divided into following five parts:

1. Cervical Region. It has 7 cervical vertebrae. First vertebra is called atlas, second is axis and rest are called typical cervical vertebrae.
2. Thoracic Region. It has 12 thoracic vertebrae. Neural spine of these vertebrae is long and pointed, which provdes surface for muscle and attachment.
3. Lumber Region. It has 5 lumber vertebrae.
4.  Sacral Region. It has 5 sacral vertebrae which are permanently fused to each other. These are situated on both halves of pelvic and form a joint with pelvic girdle.
5. Caudal Region. It has 4 caudal vertebrae. These are also fused to form a triangular structure which is called coccyx.

 Sternum and Ribs:
Sternum is the bone at the mid-ventral line of the thorax to which most of the ribs are attached at their ventral ends. Ribs are formed by vertebral and sterna part. First seven pairs of ribs are called true ribs. These are joined on one side with sternum and on second side with thorax.
 Appendicular skeleton: It consists of limbs, shoulder or pectoral girdle and hip or pelvic girdles and bones of limbs.

1. Bones of the fore arm: Humerus, radius, Ulna, Carpals, Metacarpals, finger bones, etc.
2.  Bones of hind limb: Femur, Tibia, Fibula, Tarsal, Metatarsal, etc.
3. Pectoral Girdle: In mammals, two halves of pectoral girdle are situated at equal distance from the ribs on the dorsal plane. Each of it is called shoulder bones. Each half of it made up of a triangular flat bone called scapula. From its outer side a projection arises called acromion and has a cavity called glenoid cavity.
4. Pelvic Girdle: It consists of two similar halves. In each, three bones are found, ilium, ischium and pubis. Pubis bones of both halves are joined and are called pubic sysmphysis. Ilium and ischium form acetabulum cavity in which head of femur articulates by forming ball and socket joint. A hollow space is found between pubis and ischium, which is called obdurate foramen, which provides passage for obturatry artery, vein and nerve.

Solution 15:
Forelimbs consists of one humerus (anterior arm bone), one radius and one ulna (posterior arm bones), 8 carpals (wrist bones), 5 metacarpals ( palm bones) and 14 phalanges (finger bones).
Hindlimb consists of one femur bone or thigh bone, one tibia and fibula which are bones of the leg, 8 tarsals (bones of ankle), 5 metatarsals (bones of feet), and 14 phalanges (bones of fingers).

Solution 16:
The three levers found in the human skeleton are:

1. First order levers
2. Second order levers
3. Third order levers

Solution 17:

1. Ball and socket joint
2. Pivot joint

Solution 18:
In a ball and socket joint, the ball of one bone is fitted into the socket of another bone such that the ball can move in the socket. Such a joint always involves a long bone, which can move in all planes. This type of joint is found in pectoral girdle, glenoid cavity, femur and acetabulum of pelvic girdle.

Solution 19:
Forelimbs consists of one humerus (anterior arm bone), one radius and one ulna (posterior arm bones), 8 carpals (wrist bones), 5 metacarpals (palm bones) and 14 phalanges (finger bones).
Hind limb consists of one femur bone or thigh bone, one tibia and fibula which are bones of the leg, 8 tarsal (bones of ankle), 5 metatarsals (bones of feet), and 14 phalanges (bones of fingers).

Solution 20:
Biceps muscles first contract to bend the arm, following which the triceps muscles act to straighten the arm. Thus act in opposite ways and are antagonistic muscles, since they counteract each other’s action. The muscles of biceps are called flexor muscle while that of the triceps is the extensor muscle. This whole coordination of muscular action is under the nerve impulse and brain control.

Solution 21:
Muscles which counteract each other’s actions are known as antagonistic muscles. Biceps and triceps are two such muscles.

Solution 22:
Biceps cause bending of a limb or other part. Triceps cause straightening of a limb or other part.

Solution 23:
Striped, Unstriped and cardiac muscles.

Solution 24:

1.  Synovial joint is a movable joint present between the adjoining bones which can move independently. The articulating surfaces of the two bones are covered with articular cartilage. The joint is covered with a synovial membrane which secretes synovial fluid for lubrication.
2.  These are found in elbow joint, knee joint, femur and pelvic girdle, etc.
3. The cartilages cover the ends of the adjoining bones. They function to absorb shock and reduce friction during movement.
4. 1 and 5 -epiphyseal bone
   2- synovial cavity
   3- synovial fluid
   4- synovial membrane

Solution 25:

1. (a)  Scapula;
2. Shoulder joint;
3.  Humerus;
4. Bicep;
5. Tricep;
6. Radius;
7. Tricep
8. Elbow Joint;
9. Ulna.

(b) Bicep muscles and triceps are antagonistic muscles.
(c) Bicep muscles.
(d) Shoulder bones.
(e) Ball and socket joint.

PAGE NO:163

Solution 26:

1. (d) all the above
2. (c) 24
3. (b) 7
4. (a) Parietals of skull
5. (d) stapes
6. (b) Cranium
7. (c) It allows movement in all directions.

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