Selina Class 6 ICSE Solutions

Selina Concise Biology Class 6 ICSE Solutions – The Circulatory System

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Selina Concise Biology Class 6 ICSE Solutions – The Circulatory System

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Biology for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 6 Biology Chapter 6 The Circulatory System

Multiple Choice Questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

(a) Function of WBCs is to
(i) Transport oxygen
(ii) Help in clotting of blood
(iii) Provide immunity
(iv) Provide storage of food.

(b) Blood Capillary is a
(i) Broad tube
(ii) Artery with thick wall
(iii) Vein with large lumen
(iv) Narrow tube made up of endothelium only.

(c) Nucleus is absent in
(i) RBCs
(ii) VBCs
(iii) All blood cells
(iv) Liver cells.

(d) The only artery which carries deoxygenated blood is called,
(i) Hepatic artery
(ii) Pulmonary artery
(iii) Aorta
(iv) Renal artery

(e) Sphygmomanometer ni’sures
(i) Pulse rate
(ii) Heart beat
(iii) Blood pressure
(iv) Brain activity

(f) Pulmonary vein carries
(i) Oxygenated blood
(ii) Deoxygenated blood
(iii) Glucose-rich blood
(iv) C02 laden blood

(g) The blood tastes saltish due to the dissolved:
(i) Sodium chloride
(ii) Potassium chloride
(iii) Ammonium nitrate
(iv) Sodium nitrate

Short Answer Questions:

1. Differentiate between the following pair of terms:
Question 1(a)
Patelets and WBC
Answer:
Platelets

  1. These are colourless, oval or round, cytoplasmic fragments found floating in the blood.
  2. These play a major role in blood clotting.
  3. Their life span is 3-5 days and it is called thrombocytes.

WBC

  1. WBC are colourless and lack haemoglobin, larger in quantity, and have distinct oval and lobed nucleus.
  2. They prevent body from disease causing germs by providing immunity
  3. Their life span is short i.e. 5 to 20 days.

Question 1(b)
Pulmonary artery and pulmonary vein
Answer:
Pulmonary artery

  1. This involves circulation of blood from the heart to the lungs.
  2. It carries deoxygenated blood.

Pulmonary vein

  1. This involves circulation of blood to the heart from the lungs.
  2. It carries oxygenated blood.

Question 1(c)
 Vena Cava and Aorta
Answer:
Vena Cava

  1. Vena Cava is a large vein.
  2. It carries deoxygenated blood from the upper and lower parts of the body i.e. head and shoulders.

Aorta

  1. Aorta is the large artery.
  2. It carries oxygenated blood to all parts of the body through its branches.

Question 1(d)
RBC and WBC
Answer:
RBC

  1. They do not have nucleus at maturity.
  2. They possess haemoglobin and are red.
  3. They help in transport of respiratory gases.

WBC

  1. They have a large characteristic nucleus.
  2. They are colourless as they have no pigment.
  3. They help in defence mechanism.

Question 2.
Give any three differences between an artery and a vein:
Answer:
Following are the differences between the artery and a vein:
Artery

  1. Arteries carry blood from the heart to various body parts.
  2. These carry oxygenated blood (except the pulmonary artery).
  3. Blood flows with high speed and under high pressure.

Vein

  1. Veins carry blood from different body parts to the heart.
  2. These carry deoxygenatec blood (except the pulmonary vein).
  3. Blood flows with low speech and under low pressure.

Question 3.
Blood consists of two parts — a liquid part and a cellular part. Name these parts and briefly write about them.
Answer:

  1. Plasma: The plasma is a light-yellow coloured, alkaline liquid which mainly consists of:
    • Water- 90-92%
    • Proteins – 7-8%
    • Inorganic salts – 1%
    • Other substances – traces
  2. Cellular elements : These elements are of three categories:
    • Red blood cells (erythrocytes)
    • White blood cells (leukocytes)
    • Blood platelets (thrombocytes)

Question 4.
What is the role of haemoglobin in the blood ?
Answer:
The haemoglobin is the respiratory pigment which is formed of the iron containing part known as haemin and protein part known as globin. It helps to transport respiratory gases (oxygen).

5. Fill in the blanks with suitable words given below:

  1. The colour of a red blood cell is due to haemoglobin.
  2. The two lower chambers of the heart are called ventricles.
  3. The blood plasma contains a dissolved substance such as nutrient, proteins, waste products and harmones.
  4. The pulmonary artery takes the blood from the ventricles to the lungs.
  5. The instrument used to find out the blood pressure is known as sphygmomanometer.
  6. The blood loaded with carbon dioxide from the body comes into the right auricle of the heart.
  7. The oxygen-rich blood from the lungs comes into the left ventricle of the heart.
  8. The oxygen-rich blood is pumped into different parts of the body through aorta.
  9. The carbon dioxide loaded blood from right ventricle is pumped into the lungs through pulmonary artery.
  10. The liquid part of coagulated blood is known as serum.

Question 6.
In which organ of our body does blood get oxygenated?
Answer:
Blood becomes oxygenated in the lungs. The oxygenated blood is returned to left verticles by the pulmonary vein.

Question 7.
Which side of the heart (left or right) contains oxygenated blood?
Answer:
The left side of the heart contains oxygenated blood.

Question 8.
 Name the disease in which the number of platelets reduces to 25,000 – 30,000 per cubic mm of blood. State its major symptoms.
Answer:
Dengue fever is one such disease in which the number of platelets get reduced to as low as 25-30 thousands per cubic mm of blood. The major symptoms of dengue are high fever, rashes or red spots on body, nausea or vomiting, pain in abdomen, back, or back of the eyes and muscles.

Long answer Questions

Question 1.
Name the three kinds of blood vessels found in human beings. With the help of suitable diagrams, differentiate between them.
Answer:
The three kind of blood vessels found in human beings are arteries, veins and capillaries.

  1. Arteries are the blood vessels that carry blood from the heart to the various parts of the body.
  2. Veins are the blood vessels that carry blood from the body parts to the heart.

Capillaries: These are the terminal branches of an artery, which rejoin to form a vein. A capillary is a very narrow tube whose walls have a single layer of cells with no muscles. Although the wall of a capillary is very thin, yet an exchange of nutrients, waste products and gases take place between the blood and the body fluids.
Selina Concise Biology Class 6 ICSE Solutions - The Circulatory System 1

Differences:
Arteries

  1. Carry blood away from the heart.
  2. Have thick and more muscular walls.
  3. Carry oxygenated blood (except pulmonary artery which carries deoxygenated blood).
  4. The blood flows with j erks and under great force.

Veins

  1. Carry blood towards the heart.
  2. Have thin and less muscular walls.
  3. Carry deoxygenated blood (except pulmonary vein which carries oxygenated blood).
  4. The blood flows smoothly and under little pressure.

Capillaries :

  1. Arteries after entering an organ divide into number of smaller branches called arterioles which further divide repeatedly to form a network of fine branches called capillaries.
  2. The walls of the capillaries are very thin and are one cell deep.
  3. The Capillaries after the metabolic exchange unite to form larger vessels called venules, which again unite to form a vein.

PQ. During surgical operations or during accidents, the patient may be given blood from outside to save his life. What is the technical name of this process ? Briefly explain the precautions to be taken in this process.
Answer:
During surgical operation or an accident when excess of bleeding takes place, the patient may be given blood from outside to save his life.
The transfer of blood from the donor to the recipient is called blood transfusion.
The following precautions are taken before the blood is given to the needy person:

  1. Matching of the donor’s blood with that of the recipient should be done.
  2. It should be made sure clinically that blood of donor is free from any infection.
  3. Sterilization of all the instruments to be used during the operation is must.

Question 2.
State briefly, the difference between white blood cells and the red blood cells.
Difference between white blood cells and the red blood cells
Answer:
RBC

  1. They do not have nucleus atmaturity.
  2. They possess haemoglobin and are red.
  3. They help in transport of respiratory gases.
  4. Life span is 120 days.
  5. They are about 5 million/mm3of blood.
  6. In the embryonic stage the RBC are formed in the liver and spleen. But after birth, they are formed in the red bone marrow.

WBC

  1. They have a large characteristic nucleus.
  2. They are colourless as they have no pigment.
  3. They help in defence mechanism.
  4. WBC have a short life.span of 5 to 20 days.
  5. They are about 7000/mm3of blood.
  6. WBC are formed in the red bone marrow.

Question 3.
You can see some blood vessels on the outside of the hands specially in older people. Are those veins or arteries ? How can you confirm your answer ?
Answer:
In older persons the skin becomes loose as the fat below becomes less with age and the vessels passing through these areas especially on the outside of the hands become prominent. These are veins as they flow superficially. The veins are thin and less muscular. These carry the blood to the heart veins are placed superficially so they are easily visible to the eye and are prominent.
The blood in the veins will be carrying CO2 and will have many substances like sugar, amino acids, chemicals and bacteria.

Question 4.
Given alongside is a diagram of human heart showing its internal structures. Label the parts marked 1 to 6, and answer the following questions.
Selina Concise Biology Class 6 ICSE Solutions - The Circulatory System 2
(a) Which types of blood is carried by the blood vessel marked 2?
(b) Name the main artery which takes the blood from heart to different parts of the body?
(c) Which chamber of the heart receives deoxygenated blood from the body?
(d) Which chamber of the heart receives oxygenated blood from the lungs ?

Answer:

  1. Left pulmonary artery
  2. superior vena cava
  3. Left pulmonary vein
  4. Right auricle
  5. Left auricle
  6. Left ventricle

(a) Deoxygentated blood.
(b) Aortic arch (Aorta).
(c) Right Atrium.
(d) Left Atrium

Selina Concise Biology Class 6 ICSE Solutions – Habitat and Adaptation

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Selina Concise Biology Class 6 ICSE Solutions – Habitat and Adaptation

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Biology for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 6 Biology Chapter 8 Health and Hygiene

Multiple Choice questions:
1. Put a tick mark (✓ ) against the correct alternative in the following statements:

(a) In cactus plant found in desert regions, the photosynthesis occur in:
(i) leaves
(ii) spines
(iii) modified roots
(iv) modified stem

(b) The animals such as birds have:
(i) light pneumatic bones
(ii) solid heavy bones
(iii) heavy pointed bones
(iv) no bones

(c) The biotic components of environment includes:
(i) greeen plants
(ii) animals
(iii) decomposer
(iv) all of these

(d) The presence of hollow plant stems is the characterstics of:
(i) desert plants
(ii) aquatic plants
(iii) mountaineous trees
(iv) none of these

(e) Slow breathing is the characterstics of:
(i) desert animals
(ii) aquatic animals
(iii) aerial animals
(iv) mesophytic animals

(f) Diversity of organisms are found in the different habitats because of different for
(i) average temperature
(ii) soil type
(iii) annual precipitation
(iv) all the these

Short Answer Questions:

Question 1.
List any four abiotic factors which affect different living beings.
Answer:
The various non-living things, such as soil, rocks, air, water, temperature, etc. are its abiotic components.

Question 2.
How is a whale similar to a fish in adaption to life in water ? Explain any two features.
Answer:
Whale are marine mammals. Its huge body is also spindle — shaped (streamlined). It front legs are modified into paddles or flippers for kicking water, hind limbs are absent. Whales have to periodically come up to the surface of water to breathe-inthe atmospheric air into their lungs.

Question 3.
Describe any two adaptations seen in desert plants.
Answer:
The adaptations seen in desert plants are :

  1. Well-developed root systems.
  2. Leaves either very small or converted to spines.
  3. Stem is green and fleshy in some plants.

Question 4.
Describe the aerial adaptations in birds.
Answer:
The bird’s body is perfectly adapted for aerial life. Various aerial adaptations found in birds are:

  1. Body shape: The body of birds is streamlined. Necks stretched forward with the head pointed in front and a narrowed tail at the end provide them a sleek shape. The body surface is smooth to minimize resistance against air.
  2. Wings: The forelimbs are modified into wings.The fingers are very much reduced. The whole length of the forelimb carries long flight feathers.         .
  3. Steering and brakes: The feathers on the tail help to slow down the speed and also help in steering (changing direction).
  4. Wing muscles: These are the much strong, active and enlarged breast muscles.
  5. Cutting down the body weight: Except for the most necessary bulky heavy wing muscles, the rest of the bird’s body tends to be light to facilitate flight.
  • Bones have air cavities.
  • Much less water is required in the body. The birds excrete solid urine (formed of uric acid instead of urea which otherwise requires much water to be excreted out).
  • Right ovaiy and oviduct are greatly reduced.

Question 5.
Briefly explain the term “Habitat”.
Answer:
The place where animals survive, flourish and reproduce is known as habitat. A suitable habitat should be safe and food should be available in plenty. The climate of the habitat should be favourable for the animals living there.

Question 6.
Give two adaptations in animals found in mountain habitat by which they protect themselves from the cold climate.
Answer:
Animals living in the mountain regions are also adapted. Such adaptations are basically to protect them from cold and snow. For example, yak has thick skin covered with fur to protect it from cold. Mountain goat has thick fur on its body including feet and toes. These animals have strong hooves for running up rocky slopes of the mountains.

  • The oxygen content in the mountain air is thin. So the blood of most of these animals contains more red blood cells. This helps them to breathe in sufficient oxygen even when air pressure is low.
  • Some animals hibernate or go for a long winter sleep when the temperatures are very low. In this way they conserve their energy and survive the winter without food. Frogs, and hedgehogs are some animals which hibernate.

Question 7.
Define the following: habitat, adaptation.
Answer:
Habitat — The place where a biotic community lives is called a habitat. It includes plants, animals along with their physical environment.

Question 8.
List the environmental factors that influence a habitat.
Answer:
Environment in which that organism generally lives. The special feature of habitat is that this environment includes all the physical characteristics around (air, water, temperature, etc.), along with the effective plants and animals. Forexample, a pond is the habitat of a fish where it lives with other organisms and also interacts with water, air, temperature, etc. The natural home of an organism (niche) and its immediate surroundings is called its habitat. The habitat of any living creature should be a place where it can find shelter, food, water and suitable conditions for breeding.

Question 9.
Differentiate between an aquatic habitat and a terrestrial habitat.
Answer:
Habitats of plants and animals that live in water are called aquatic habitat.The plants and animals that live on land are said to live in terrestrial habitats

Question 10.
Name any three types of terestrial habitat.
Answer:
The plants and animals that live on land are said to live in terrestrial habitats: For example, forests, grasslands, deserts, coastal and mountain region.
The three types of terrestrial habitat are:

  • Desert habitat — Vast regions of sand, high daytime temperatures and low night time temperatures, very little water are the main environmental factors of this habitat.
  • Mountain habitat — Rocky land, snow and ice laden regions are the main features of this habitat. Temperatures in the mountains change with altitude. The lower regions are cooler whereas at higher altitudes it gets extremely icy and cold.
  • Polar habitat—is extremely cold and covered with snow throughout the year. Polar bears, reindeer, penguins and very scanty plant growth survive in the cold regions.

Question 11.
Name two types of terrestrial habitats with low temperature.
Answer:
Desert habitat — Vast regions of sand, high daytime temperatures and low night time temperatures, very little water are the main environmental factors of this habitat.

Mountain habitat — Rocky land, snow and ice laden regions are the main features of this habitat. Temperatures in the mountains change with altitude. The lower regions are cooler whereas at higher altitudes it gets extremely icy and cold.

Question 12.
Complete the table given below. Write down two points in each given column.
Selina Concise Biology Class 6 ICSE Solutions - Habitat and Adaptation 1

Answer:
Selina Concise Biology Class 6 ICSE Solutions - Habitat and Adaptation 2

Selina Concise Physics Class 6 ICSE Solutions – Magnetism

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Selina Concise Physics Class 6 ICSE Solutions – Magnetism

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Physics. You can download the Selina Concise Physics ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Physics for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 6 Physics Chapter 6 Magnetism

  • Synposis
  • The first natural magnet was discovered in Magnesia, a town in Greece. It was called the lodestone.
  • Artificial magnets are made of iron or steel. They are made of different shapes namely the bar magnet, cylinderical magnet, U-shaped magnet, horse-shoe magnet, magnetic needle and compass.
  • The materials which are attracted by a magnet are called magnetic materials. Examples: iron, steel, cobalt.
  • The materials which are not attracted by a magnet are called non-magnetic materials. Examples: paper, wood, brass, plastic, copper aluminium, etc.
  • A magnet has two poles, a north and a south pole.
  • A magnet has the following properties:
  1. A magnet attracts the small pieces of iron.
  2. A magnet always rests in the north-south direction, if it is free to swing.
  3. Like poles repel each other and unlike poles attract each other.
  4. Poles always exist in pairs, cannot be isolated.
  • Magnets are used to separate iron and steel from their mixture with non-magnetic substances. –
  • Magnets are used in many electrical appliances such as electric . bell, loud-speaker, etc.
  • A magnetic compass is used by sailors and navigators to find the north-south direction.
  • Magnetic induction is the process in which a piece of iron temporarily behaves like a magnet in the presence of another magnet.
  • When a magnet is placed near an iron piece, the iron piece behaves like a magnet. The end of the iron piece near the north pole of the magnet becomes a south pole while the farther end becomes a north pole.
  • It is because of magnetic induction that a magnet attracts a piece of iron.
  • An iron piece can be made into a magnet by any of the following methods:
  1. Magnetic induction
  2. Single touch method
  3. Double touch method
  4. Electrical method
  • In the single touch method, we need a single magnet, but in the double touch method we need two magnets, hi these methods, the end touched last by the magnet has the polarity opposite to that of the striking pole.
  • Powerful magnets are made by the electrical method.
  • Electromagnets or temporary magnets are made of soft iron.
  • Permanent magnets are made of steel.
  • Electromagnets are used in devices like electric bell, magnetic toys, telephone etc.
  • Permanent magnets are used in devices like galvanometer, ammeter, voltmeter etc.
  • A magnet can be destroyed by rough handling, by dropping it several tunes, by hammering it repeatedly and by heating it.
  • The magnetic field around a magnet is the space in which a magnetic substance such as small iron piece experiences a force of attraction.
  • The earth itself behaves like a magnet. It has its own magnetic field.
  • The south polarity of the earth is near the geographic north pole and the north polarity of the earth is near the geographic south pole.
  • Magnetic keepers are used to store the magnets.
  • Magnetic keepers are small pieces of soft iron.

ACTIVITY 1

Magnetic objects
Iron, Steel, Cobalt, Nickel
Non-magnetic objects
Wood, Stone Plastic, Rubber Copper, Sand, Gold, Silver, Brass Paper, Aluminium

Test yourself

A. Objective Questions

1. Write true or false for each statement.

(a) Artificial magnets are weaker than the natural magnets.
Answer. False
Artificial magnets are stronger than the natural magnets.

(b) Poles of a magnet cannot be separated.
Answer. True

(c) A magnet can attract only a magnetic substance.
Answer. True

(d) A magnet has no effect when it is heated to a high temperature.
Answer. False.
A magnet get demagnetised when it is heated to a very high temperature.

(e) Permanent magnets get easily demagnetised.
Answer. False.
Permanent magnets cannot be demagnetised.

(f) Magnetic poles occur in pairs.
Answer. True

(g) Single touch method is better than the electrical method for making a magnet.
Answer. False.
Electrical method is better than single touch method.

(h) Magnetic keeper is a wooden piece.
Answer. False.
Magnetic keepers are the pieces of soft iron.

(i) Copper cannot be magnetised.
Answer. True

2. Fill in the blanks

(a) Temporary magnets are usually made up of soft iron.
(b) Rough handling destroys the magnetic properties of a magnet.
(c) Like poles repel each other.
(d) A freely suspended magnet points in the north-south direction.
(e) In a magnet, ends have the maximum attractive property.
(f) A magnet has two poles.

3. Match the following
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 1

4. Select the correct answer

(a) If we suspend a magnet freely, it will settle in .

  1. east-west direction
  2. north-south direction
  3. north-east direction
  4. east-south direction

(b) Making a magnetic substance a magnet by bringing it closer to another magnet without touching it, is

  1. magnetic induction method
  2. single touch method
  3. double touch method
  4. electrical method

(c) An example of natural magnet is

  1. iron
  2. steel
  3. lodestone
  4. none of above

(d) The artificial magnet used to detect direction in the laboratory is

  1. U-shaped magnet
  2. horse shoe magnet
  3. electromagnet
  4. magnetic compass

B. Short/Long Answer Questions

Question 1.
What is a magnet ?
Answer:
The substances which have the property of attracting iron, are called magnets.

Question 2.
What are magnetic and non-magnetic substances ? Give two examples of each.
Answer:
Magnetic substances: The substances that get attracted by a magnet are called magnetic substances. Iron, steel, cobalt and nickel are magnetic substance
Non-magnetic substances : The substances that do not get attracted by a magnet are called non-magnetic substances, e.g., wood, plastic, copper, paper, aluminium, rubber, stone.

Question 3.
What are natural and artificial -magnets ?
Answer:
Natural magnets: Natural magnets are those which are found in nature e.g. load stone.
Artificial magnets: Man made magnets are called artificial magnets, e.g. electromagnet.

Question 4.
How is an artificial magnet prepared from a natural magnet ?
Answer:
Pieces of iron or other materials are made magnets by rubbing them with natural magnets (or by passing direct current through a wire wound around them). This is how artificial magnets are made.

Question 5.
State two ways of magnetising an iron piece.
Answer:
The two ways of magnetising an iron piece are:

  1. Magnetic induction method.
    Take a long iron nail and test it for magnetic properties by bringing near the magnetic substances. You will see nail does not attract the magnetic substances. Now bring near a pole of a bar magnet to the head of the nail. Now bring the iron paper clips near the pointed end of the nail, you will observe that the iron paper clips now get attracted towards the nail. This is because iron nail has become magnet. Now take the bar magnet away form the iron nail, paper clips fall off. This magnetism is temporary.
    Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 2
  2. Single touch method: Take a demagnetised piece of iron. Place it on a table surface. Take a magnet and select its one pole. Now mb it with the selected pole on the iron in one direction for several times. After sometime, the iron piece turns into a magnet.
    Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 3

Question 6.
How can magnetic properties of a magnet be destroyed ?
Answer:

  1. By hammering the magnet repeatedly.
  2. By rough handling
  3. By heating.

Question 7.
Why docs a freely suspended magnet always rest in north- south direction ?
Answer:
A freely suspended magnet always rest in north-south direction because the north-pole of the magnet lies in the geographic north direction and the south pole of the magnet lies in the geographic south direction. So it aligns itself in N-S direction. As unlike poles attract and like poles repel.

Question 8.
Draw diagrams of the artificial magnets of four different shapes.
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 4

Question 9.
Why are the artificial magnets preferred over the natural magnets ?
Answer:
Artificial magnets are preferred over natural magnets because natural magnets are weak and often irregular in shape, they can readily be magnetised and demagnetised by turning the current on or off in the coil.

Question 10.
Describe an experiment to show that the maximum attractive property is at the poles of a magnet.
Answer:
Take a bar magnet and place a steel pin at some distance. We observe that nothing happens. Now, bring the steel pin near the pole of the bar magnet. We notice that pin sticks to the magnet. This experiment shows that maximum magnetic force acts at the poles of the magnet.

Question 11.
State four important properties of a bar magnet.
Answer:

  1. Attractive property: A magnet can attract small pieces of iron filing or other ferromagnetic materials.
  2. Directive property: If a magnet is suspended horizontally by a thin thread (say silk thread), it rests always pointing north- south direction of earth.
  3. Like poles always repel each other and unlike poles attract each other.
  4. Poles always exist in pairs : Single pole can never exist.

Question 12.
Explain the attractive property of a magnet with the help of an experiment.
Answer:
Take iron filling on a piece of paper. Bring a bar magnet near it. Iron filling will cling to it. It shows the attractive property of magnet.

Question 13.
Describe the method by which an iron bar can be made a magnet.
Answer:
Single touch method : Place the iron bar (or the needle) AB on a table. Take a bar magnet NS and place it almost vertical with its north pole (N) on the end A of the bar.
Move the magnet along tire iron bar till the other end B is reached.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 5
Lift the magnet at the end B and again place it on the first end A Again stroke the bar. Repeat the process about 20 times. Then turn the iron bar AB upside down. Again stroke it with the magnet about 20 times. The bar now becomes a magnet.

Question 14.
How are the magnets kept safely ? What is the role of keepers in storing the magnets ?
Answer:
When magnets are not in use they should be kept and stored in magnetic keepers. The magnetic keeper are the pieces of soft iron. A magnetic keeper has a card board with one or two iron soft pieces. Two magnets are placed in such a way that their opposite poles are close to each other and then a soft iron keeper is attached with it.

Question 15.
Define the term magnetic field of a magnet. How will you recognise it experimentally ?
Answer:
The space around a magnet in which if a magnetic substance such as small pieces of iron, are placed, they get attracted to-wards the magnet, is called the magnetic field.
Recognition of the magnetic field around a magnet: If a magnet is placed below a sheet of stiff paper and some iron filings are spread on it, then on tapping the sheet gently, the iron filings are found to arrange themselves in a definite pattern as shown in fig.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 6

Question 16.
How will you make an iron bar electromagnet ? Draw a diagram showing the polarities of the electromagnet.
Answer:
Take the given iron bar AB. Wound several turns of insulated copper wire over the bar. Connect the ends of the wire to a battery through a switch. Press the switch to pass current. After some time, the bar AB becomes a magnet.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 7
The end A of the bar at which the current enters the coil in clock¬wise direction becomes the south pole (S) and the end B of the bar at which the current leaves the coil in anti-clockwise direction becomes the north pole (N).

Question 17.
State two ways of increasing the strength of an electro Magnet
Answer:
Strength of the electromagnet: The strength of the electromagnet can be increased:

  1. by increasing the current in the coil, and
  2. by increasing the total number of turns of the coil.

Question 18.
Suppose you are given a long bar magnet and you are asked to break it into four small magnets. Draw diagrams showing the polarities of each broken part.
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 8

Question 19.
State three important uses of a magnet.
Answer:
Use of magnet:

  1. Magnets are used in magnetic compass, door bells, refrigerators.
  2. Magnets are used in dynamos, motors, loudspeakers, microphones etc.
  3. Ceramic magnets are used in computers.
  4. Magnets are used in toys to give magic effect.

Question 20.
What is magnetic induction ? Explain with the help of a diagram.
Answer:
Magnetic Induction: The property by which an ordinary piece of iron acquires magnetic properties temporarily due to the pres¬ence of another magnet close to it, is known as magnetic induction
Take a long nail. Put it on the arm of a stand. Spread some iron pins on the base of stand. You will find that the pins do not get attracted towards the nail. Now touch a magnet at the end of nail. As the end is brought close to the head of nail, some pins cling to the nail. It happens because the nail turns into magnet and acquires the properties of magnetism. The moment you remove the magnet from the head of the nail. The pins will fall down. It will no more be a magnet.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 9

Question 21.
In which direction does a suspended bar magnet come to rest? Give reason.
Answer:
A magnet always rests in North and South direction, i.e. N-end always towards North of Earth and S-end towards South of Earth.

Question 22.
State three differences between the temporary and permanent magnets.
Answer:
Temporary magnet

  1. It is made up of soft iron.
  2. The magnet which loses its magnetism as soon as magnetising force is removed away from it.
  3. Because of its weak power, it is not used to make iron piece into magnet.

Permanent magnets

  1. It is made up of steel, cobalt and nickel.
  2. The magnet, which does not lose its magnetic properties easily is called permanent magnet.
  3. It can convert ordinary piece of iron into a temporary magnet.

Question 23.
State three ways of demagnetising a magnet.
Answer:
A magnet can be demagnetized in the following ways 

  1. rough handling
  2. hammering the magnet several times.
  3. passing an alternating current around the magnet.
  4. dropping the magnet on the floor several times.
  5. heating the magnet to a very high temperature.

Question 24.
Suggest one way to recognise the magnetic field of the earth.
Answer:
If we suspend a magnet such that it is free to swing, we see that it always rests in the north-south direction. The north pole of the magnet lies in the geographic north direction and the south pole of the magnet lies in the geographic south direction. So it aligns itself in N-S direction.

Question 25.
Name the material of core of an electromagnet for

  1. temporary magnet
  2. permanent magnet.

Answer:

  1. They are made of soft iron.
  2. They are made of iron, steel, cobalt, nickel or an alloy called ANILCO.

Question 26.
You are given an iron nail, a torch cell and a long piece of insulated copper wire. With the help of a labelled neat diagram, describe in steps how you will make the nail, an electromagnet.
Answer:
Aim : To make an electromagnet.
Materials Required : An iron nail, a battery, a switch, some insulated copper wire and some iron paper pins.
Procedure : Coil the insulated copper wire around the iron nail. Connect the ends of the wire to the battery through the switch. Close the switch so that electric current flows through the copper wire. Now bring the iron paper pins close to the iron nail.
Observation And Conclusion : The paper pins get attracted to the nail, showing that the nail has turned into an electromagnet. Now, if you switch off the current, the iron paper pins will drop off the iron nail.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 10

Question 27.
Describe an experiment to illustrate that like poles repel while the unlike poles attract.
Answer:

  1. Take two bar magnets A and B. Suspend one magnet A with a silk thread from a support so that it is free to swing. The magnet will come to rest in the north-south direction. The north pole of the magnet is in the north direction and the south pole of the magnet is in the south direction.
  2. Now holding the other magnet B in your hand, bring its north pole near the north pole of the suspended magnet A (such that the two magnets do not touch each other) as shown in figure. You will observe that the suspended magnet A moves away from the magnet B. This shows that the like poles repel each other.
    Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 11

Now bring the south pole of the magnet B near the north pole of the suspended magnet A as shown in figure, without touching it. You will observe that the magnet A moves towards the magnet B. This shows that the unlike poles attract each other.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 12

Question 28.
What are magnetic keepers ? Name its material.
Answer:
Magnetic keepers are used to store the magnets. Magnetic keepers are small pieces .of soft iron.

Question 29.
How are the north and south poles of a magnet located ? Explain.
Answer:
Suspend a bar magnet with a silk thread from a wooden stand as shown in figure. The magnet swings for some time and then eventually comes to rest in a particular direction i.e., north-south direction. If we disturb the magnet a little, the magnet again comes to rest in the north-south direction.
Selina Concise Physics Class 6 ICSE Solutions Chapter 6 Magnetism 13
The end of the magnet which points towards the north is called the north seeking pole or simply the north pole and the end which points towards the south is called the south seeking pole or simply the south pole. The north and south poles are marked by the letters N and S respectively.

 

Selina Concise Biology Class 6 ICSE Solutions – The Flower

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Selina Concise Biology Class 6 ICSE Solutions – The Flower

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Biology for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

Selina Class 6 Biology ICSE SolutionsChemistryPhysicsMathsGeographyHistory & Civics

Selina Concise ICSE Solutions for Class 6 Biology Chapter 2 The Flower

Review Questions

Multiple Choice Questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

(a) In a germinating seed, the roots develop from:
(i) Radicle
(ii) Plumule
(iii) Tegmen
(iv) Hilum

(b) In a germinating seed, the shoot develops from:
(i) Radicle
(ii) Plumule
(iii) Tegmen
(iv) Hilum

(c) Which one of the following is a monocotyledonous seed ?
(i) Bean
(ii) Pea
(iii) Maize
(iv) Gram

(d) If the cotyledons are pushed above the soil, then such type of germination is called :
(i) Epigeal
(ii) Hypogeal
(iii) Perigeal
(iv) Progeal

(e) If the cotyledons remain under the soil, then such seeds type of germination is called:
(i) Epigeal
(ii) Hypogeal
(iii) Perigeal
(iv) Progeal

(f) Pollen is produced in the:
(i) Filament
(ii) Style
(iii) Pistil
(iv) Anther

(g) Reproductive whorls of a flower are:
(i) Stamens and carpels
(ii) Sepals and petals
(iii) Sepals and stamens
(iv) Petals and carpels

PQ. Vegetative propagation is not observed in:
(i) Potato
(ii) Tomato
(iii) Pea
(iv) Bean

(h) Which one of the following is a false fruit ?
(i) Tomato
(ii) Apple
(iii) Potato
(iv) Pea

(i) In a seed, food is generally stored in:
(i) Radicle
(ii) Plumule
(iii) Fruit
(iv) Catyledons or endosperms

1. Given below is a longitudinal section of a bean seed. Label the parts marked 1 to 5 and write their functions.
Selina Concise Biology Class 6 ICSE Solutions - The Flower 1
Answer :
1. Testa (seed coat)
2. Plumule
3. Radicle
4. Micropyle
5. Cotyledon

  1. Testa (seed coat) — It protects the seed from insects and bacteria as well as from mechanical injury.
  2. Plumule — Plumule develops into a shoot.
  3. Radicle — Radicle develops into a root
  4. Micropyle — The micropyle absorbs as much water as is required for germination.
  5. Cotyledon — Contain stored food material which is used by the seeding during germination.

2. Name the following:

(a) A seed which shows hypogeal germination.
Ans. pea seed, maize. seed
(b) Amonocotseed.
Ans. Maize seed, wheat seed
(c) A dicot seed.
Ans. Bean seed, gram seed, pea seed
(d) A seed which shows epigeal germination.
Ans. Bean seed castor seed, tamarind seed

Question 3.
Differentiate between the following pairs of terms:
Answer :
(a) Radicle and plumule.
Radicle: In a seed the radicle lies downwards near the lower pointed end of the grain. It gives rise to the root.
Plumule: In a seed the plumule lies upwani near the cotyledon and gives rise to the shoot.

(b) Ilium and micropyle.
Answer :
IlIum : On one side of seed câat, there is scar called hi hum, which marks the place where the seed was attached to the fiiüt wall.
Micropyle : Above the hilum is a small pore called micrope. The micropyle absorbs as much water as is required for germination

(c) Testa and tegmen.
Answer :
Testa: The seed is protected by a thick outermost coat called the testa or seed coat.
Tegmen: Under the testa lies a very thin membrane called the tegmen.

Question 4.
Give two functions of a fruit.
Answer :
Functions of a fruit are:

  1. Fruit is a protective case for the seeds.
  2. Fruit is a temptation to animals and man to eat it and scatter the seeds

Question 5.
Match the columns :
Column A           Column B
Selina Concise Biology Class 6 ICSE Solutions - The Flower 2
Answer :
Selina Concise Biology Class 6 ICSE Solutions - The Flower 3

Question 6.
Radicle emerges out of the seed earlier than plumule.What one advantage is served by this ?
Answer :
Radicle comes out of the seed earlier than the plumule has advantages as it gets water and minerals from the soil and gives it to the growing plumule.

Question 7.
State whether the following statements are True or False.

(a) Some seeds have no cotyledons.
False
(b) Warmth is necessary for the germination of seeds.
True
(c) All seeds have two cotyledons.
False
(d) Oxygen is necessary for the germination of seeds.
True

Question 8.
State one function of the following:
(a) radicle
(b) cotyledons
(c) endosperm
(d) micropyle
Answer :

  1. Radicle — form the roots
  2. Cotyledons — On removing th& testa and the tegmen from a soaked bean seed, you will find that the seed is made up of two fleshy seed leaves called the cotyledolm. They contain stored food material which is used by the seedlling for growth.
  3. Endosperm—ovary forms the fruit.
  4. Micropyle —Above the hilum is a small pore called micropyle (micro = small, pyle = passage). The micropyle absorbs and allows as much water as is required for germination.

Question 9.
The three conditions necessary for germination of seeds are (tick the correct answer):
(a) Oxygen, suitable temperature and water.
(b) Good soil, water and air
(c) Good soil, suitable temperature and light.
(d) Light, oxygen, and temperature.
(e) Oxygen, carbon dioxide, and light.

Question 10.
 Name the part of the seeds from which the following are given out:
(a) Roots : .
(b) Leaves :
Answer :
(a) Roots — Radicle give rise to roots.
(b) Leaves—Plumule gives rise to shoot bearing leaves.

Question 11.
In the spaces provided below, draw labelled diagrams to show the three stages in the germination of any seed you have observed.
Answer :
Selina Concise Biology Class 6 ICSE Solutions - The Flower 4

Long Answer Questions
(Write the answers in your note-book)

Question 1.
What is meant by pollination ? Name the two types of pollination.
Answer :
The transfer of the pollen grains from the anthers to the stigma of a flower is called pollination.
The two types of pollination found in flowering plants are.

  1. self-pollination – that occurs within the same plant.
  2. cross-pollination – that occurs between two flowers of two different plants but of the same kind.

Question 2.
Imagine that all the seeds produced by a plant happen to fall under the same plant and sprout into new plants. Mention any two problems that will be faced by the new plants.
Answer :
If all the seeds produced by a plant happen to fall under the same plant and sprout into new plants then in this situation plants will face the following problems:

  1. A large number of plants will grow in a small limited space. The water and the minerals available to them in the soil will be limited.
  2. The air surrounding them will not be enough and less sunshine will be available to them. As a result, most of these sprouted plants will die.

Question 3.
What is a flower ? Draw a typical flower and label its different parts.
Answer :
Selina Concise Biology Class 6 ICSE Solutions - The Flower 5
A flower is a reproductive part of a plant. It helps in sexual reproduction as it has male parts and female parts.
A fully opened flower has the following parts:
Stalk—A flower is attached to the shoot by means of stalk or pedicel stalk. The tip of the stalk is swollen or flattened. This is called toms or thalamus or receptacle.
The different parts of a flower are inserted on the thalamus. There are usually four whorls as Calyx

  • (Sepals)
  • Corolla (Petals)
  • Androecium (stamens)
  • Gynoecium (Carpels)
  • Present on the thalamus.
  1. Sepals (Calyx): These are the outermost part of the flower. These are leaf like and green in colour. This is the outer covering of the flower and form outer whorl in a flower. The Calyx (sepals) enclose the inner parts of the flower when it is a bud. It is protective in function.
  2. Corolla (Petals): Petals form the second whorl inner to the sepals. These are usually coloured, gaudy, or white in colour and scented and give sweet smell. The value of a flower is due to the attractive colour of the petals. These attract the insects for pollination.
  3. Stamens (Androecium): The third whorls inner to the petals are stamens. This third whorl is called Androecium. These are the male parts of the flower. Each stamen is formed of a long narrow, hair like structure called filament. On its tip it bears a rounded broad sac like structure called anther. Each anther has two anther lobes. Each anther lobe has two pollen sacs which have powdery mass called pollen grains.
  4. Carpels (Gynoecium): Carpels are the inner most or fourth whorl in a flower. It is lodged on the thalamus and forms the female part of a flower. This whorl of carpels is called gynoecium. Each carpel or pistil has three parts,
    1. The lower most, swollen part is ovary. It is attached to the thalamus
    2. The middle part is style which is narrow, thread like
    3. Stigma: The style ends in a knob like, rounded structure which is sticky in nature to receive the pollen grains.The ovaries contain ovules which later turn into seeds after fertilization and the ovary wall forms the fruit sometimes the thalamus also becomes a part of the fruit as in apple.

Question 4.
With the help of a suitable labelled diagram, describe the structure of a dicot seed.
Answer :
Selina Concise Biology Class 6 ICSE Solutions - The Flower 6

It is a dicotyledonous and non-endospermic seed. It is produced in a long cylindrical pod (fruit – phali) External characters. The seed is brown or whitish brown in colour. The seed is hard and smooth and kidney shaped i.e.Convex on one side and concave on the other side. Concave side bears whitish scar called hilum. It is the place which is attached to the wall of the pod through a stalk called funicle. At one side of the hilum is a small pore called micropyle water enters through it.

Internal structure — The seed is covered by a hard, tough covering called testa. Inner to the tests is the embryo. Embryo consists of two cotyledons and embryo axis. Embryo axis has plumule and radicle. The plumule is present in between the two cotyledons and its top bears two folded tiny leaves. It forms future shoot and leaves of the growing seed. Radicle is rod shaped and is out of the two cotyledons. It forms the root of the growing seed. When the seed grows the two cotyledons come out of the soil and form cotyledonary leaves and turn green in colour. Cotyledons give food to the growing seedling as it has food. The germination in this seed is epigeal as cotyledons come outside the soil in the growing seed.

Question 5.
Define germination ? Name the two types of germination. Explain with examples.
Answer :
The growth and development of the embryo present in the seed into a seedling (or a young plant capable of independent existence) is called as seed germination.
The embryo in a seed remains inactive or dormant. When the seed is put into the soil and given water and under suitable temperature, the embryo becomes active on absorbing the water and the embryo turns into a seedling.

Types of germination — There are three types of germinations.
(i) Epigeal
(ii)Hypogeal
(iii) Viviparous
(i) Epigeal germination — Epi means above ; geo-ground (earth)
When the cotyledons in growing seed come out of the soil it is epigeal type of germination as in case of castor seed, cucumber, tamarind, bean seed the cotyledons come out of the soil and turn green. These are called cotyledonary leaves. These cany on photosynthesis till new leaves arise.

(ii) Hypogeal germination—Hypo-below, gea soil.
When in a growing seed the cotyledons remain under the ground as in case of gram, pea, groundnut and maize. The plumule firms the aerial shoot to which bears leaves and the radicle gives rise to roots. The growing seedling gets food from the cotyledons. As the seedling grows the cotyledons die in the soil.

(iii) Viviparous germination—This is special type of germination.
This occurs in plants growing along the sea coasts and in salt lakes. The seed start growing while it is still attached to the plant as in mangrove plants. The embryo comes out of the fruit with a long, dart like radicle. It falls directly into soft, slushy, wet mud. The radicle gives root and establishes as a seedling and the plumule give rise to shoot. This is in mangrove plants.

Question 6.
What are the three conditions necessary for the germination of seeds. How would you demonstrate this?
Answer: 
F or successful germination of any viable seed, three external conditions are necessary as:

  1. Water or moisture
  2. Warmth or temperature
  3. Air or oxygen.

We can demonstrate this with “Three seed experiment This is a simple experiment to demonstrate the necessity of these factors for proper germination.
Selina Concise Biology Class 6 ICSE Solutions - The Flower 7
Experiment:
Three seed experiment to demonstrate germination Three mature dried bean seeds are taken and tied on a wooden strip at three different positions (above the figure). This strip is placed in a beaker containing water in such a way that the lower seed is completely submerged in water, the middle seed is partially submerged inside the water and the top seed is kept above water. This set-up is left in a warm place for few days.

It is observed that the middle seed shows germination and gives out radicle and shoot leaves. The top seed shows no growth and the bottom one shows negligible growth. The middle seed gets fully germinated due to the fact that this seed has all the favourable conditions required for germination i.e., air (oxygen), moisture and warmth (favourable temperature), which are necessary for germination.

Question 7.
Give the main difference between hypogeal and epigeal and germination.
Answer :
Epigeal germination—Epi means above; geo-means ground (soil). When the cotyledons in a growing seed come out of the soil it is epigeal type of germination as in case of castor seed, bean seeds, pulses, tamarind cucumber.
The cotyledons come out of the soil and turn green these are cotyledonary leaves and carry on the function of photosynthesis till new leaves arise in the growing seedling. Hypogeal germination — Hypo-below, geo-soil it is that type of germination in which in the growing seed the cotyledons remain under the soil as in case of pea, gram, ground-nut, maize. The plumule forms the aerial shoot which later bears leaves and die radicle gives rise to root. The tiny seedling gets food from the cotyledons till it establishes itself in the soil by its roots and starts getting water and minerals and as well the new leaves arise on the ascending axis and they start making food by the process of food making.

Differences—

Epigeal germination

  1. In this type of germination the cotyledons come out of the soil.
  2. The cotyledons turn green as they come out of the soil and serve as cotyledonary cotyledons
    leaves and carry on photo¬synthesis to make food for the growing seedling.
  3. The cotyledons become pale and fall off when the ascending axis bear leaves

Hypogeal germination

  1. In this type of germination the cotyledons remain under the soil.
  2. The cotyledons remain under the ground and the seedling gets food from the till it establishes in the soil.
  3. The cotyledons get rotten up in the soil when the seedling matures.

Question 8.
State the location of the following in a flower:
Answer :

  1. Sepals: These are the outermost part of the flower. These are leaf like and green in colour. This is the outer covering of the flower and form outer whorl in a flower. The Calyx (sepals) enclose the inner parts of the flower when it is a bud. It is protective in function.
  2. Petals: Petals form the second whorl inner to the sepals. These are usually coloured, gaudy, or white in colour and scented and give sweet smell. The value of a flower is due to the attractive colour of the petals. These attract the insects for pollination.
  3. Anther—It is present at the end of a stamen. Anther has poller sacs in which pollen grains are formed. Pollen grains contain the male gametes.
  4. Stigma—It is the terminal knob-like part, it may be divided into two or more lobes and assume a feathery appearance. The stigma is covered with hair or with glandular papillae. It serves as the landing place grains for pollen during pollination.

Question 9.
 Given below is the diagram of a typical flower. Label the parts marked by guidelines.
Selina Concise Biology Class 6 ICSE Solutions - The Flower 8
Answer:
Selina Concise Biology Class 6 ICSE Solutions - The Flower 9

 

Question 10.
Give the difference in the function between the following parts:
(a) Ovary and ovule
(b) Petal and sepal
(c) Filament and style
(d) Pollen and ovule
Answer :
(a) Ovary and ovule —

  1. Ovary is the female reproductive part of a flower and ovules are located inside the ovary.
  2. Ovary after fertilization turns into a fruit whereas ovules turn into seeds of fruit.

(b) petal and sepal—Petals are colourful and attractive and helps to attract insects for pollination whereas the main function of sepals is to provide protection to the growing bud.

(c) filament and style—The filament is a stalk like structure that attaches and support the flower and support the anther which is the structure that produces pollens whereas the style transfers the male gametes of the pollen grains into the ovary.

(d) pollen and ovule — The function of pollen is to deliver male gametes (sperm) from stamen of a plant to an ovule whereas ovule, when fertilized, well developed into a seed. It is a female reproductive cell.

Selina Concise Biology Class 6 ICSE Solutions – Health and Hygiene

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Selina Concise Biology Class 6 ICSE Solutions – Health and Hygiene

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Biology for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

Selina Class 6 Biology ICSE SolutionsChemistryPhysicsMathsGeographyHistory & Civics

Selina Concise ICSE Solutions for Class 6 Biology Chapter 6 Health and Hygiene

Review Questions 

Multiple Choice questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

(a) Malaria is caused by:
(i) Bacteria
(ii) Protozoan
(iii) Fungi
(iv) Virus

(b) Deficiency of calcium causes
(i) Poor growth of teeth and gums
(ii) Goitre
(iii) Anaemia
(iv) Polio

(c) Hay fever and asthma are
(i) Deficiency diseases
(ii) Genetic diseases
(iii) Organic diseases
(iv) Allergy diseases

PQ. Cataract is a disease of:
(i) Ears
(ii) Nose
(iii) Eyes
(iv) Throat

(d) Infectious diseases can be prevented by:
(i) Medicines
(ii) Proper food
(iii) Immunisation
(iv) Exercise

(e) Which one of the following is a genetic disease?
(i) Scurvy
(ii) Leukemia
(lii) Goitre
(iv) Haemophilia

(f) Which one of the following is a degenerative disease?
(i) Thalassemia
(ii) Ben-ben
(iii) Cataract
(iv) Diabetes

(g) Pellagra is one disease caused by the deficiency of:
(i) Vit. B3
(ii) Vit. B1
(iii) Vit. C
(iv) Vit. D

(h) Deficiency of Iodine in one’s food can cause:
(i) Ben-ben
(ii) Goitre
(iii) Scurvy
(iv) Pellagra

(i) Which one of the following mineral deficiency diseases can be cured by eating a diet which include green leafy vegetables, banana, cereals, egg-yolk?
(i) Goitre
(ii) Anaemia
(iii) Brittle bones
(iv) Pain in muscle contraction

(j) Which one of the following vitamin deficiency diseases can be cured by eating a diet which includes carrot, yellow fruits, vegetables, butter, milk, fish ?
(i) Beri-beri
(ii) Dermatitis
(iii) Night blindness
(iv) Scurvy

(k) Which one of the following is a communicable disease?
(i) Measles
(ii) Cancer
(iii) Heart stroke
(iv) Allergy

Short Answer Questions:

Question 1(a).
What is a non-communicable disease ?
Answer:
The diseases which are caused due to improper functioning of the body organs e.g. diabetes, heart attack. They are not caused by germs and not transmitted from one to another.

Question 1(b).
What is a deficiency disease
Answer:
These disease are caused by lack of nutrients, vitamins, minerals as a anaemia, goitre.

Question 1(c).
What are communicable diseases ? How can they be avoided ?
Answer:
Those disease which spread from one person to another by the entry of microorganisms are known as communicable diseases. The disease-causing germs are called Pathogens. These disease can be avoided by proper vaccination, healthy food and hygenic surroundings.

Question 1(d).
Biting nails should be strictly avoided. Give reason.
Answer:
Nail biting may cause many disease as the dirt has many
bacteria causing diseases. Nails should be cut from time to time to save from diseases.

Question 1(e).
Regular exercise and proper rest is a must. Give reason.
Answer:
Regular exercise keeps our body strong and immune to many
diseases, rest refreshes our body.

Question 1(f).
 Children eating more of fast food tend to suffer from obesity (overweight). Comment.
Answer:
Fast food like pizza, burger, patty, oily foods etc. have much carbohydrates and fats. Children eating these become more and more fat and gain weight soon as they do not do much of physical work.

Question 1(g).
How can we control spreading of diseases by mosquitoes and houseflies ?
Answer:
We can control spreading of diseases by mosquitoes and houseflies by using repellants, throwing garbage in covered bins, avoiding stagnation of water and checking breeding of these insects.

2. Name the following:
(a) A bacterial disease caused due to contaminated water
Ans. A bacterial disease caused due to contaminated water Cholera.

(b) A disease caused due to Plasmodium
Ans. A disease caused due to Plasmodium Malaria.

(c) A disease caused due to the bite of female Culex mosquito
Ans. A disease caused due to the bite of female Culex mosquito Elephantiasis.

(d) A viral disease spread by the bite of a dog
Ans. A viral disease spread by the bite of a dog Rabies/ Hydrophobia

(e) Two diseases caused due to deficiency of protein in the diet of a child.
Ans. Kwashiorkor and marasmus.

(f) Any three water-borne disease.
Ans. Amoebiasis, Cholera, Hepatitis A.

(g) A viral disease caused due to unhealthy sexual contact
Ans. A viral disease caused due to unhealthy sexual contact AIDS.

(h) A disease caused due to choking of coronary artery
Ans. A disease caused due to choking of coronary artery Atheraosclerosis.

3. Write short (1-2 sentences) notes on the following:
Disease, immunisation, pathogen, allergy, AIDS.
Answer:
Disease: Disease is a departure from normal health due to structural or functional disorder of the body. Disease may be due to deficiency of nutrients or malfunctioning of organs or genetic disorders, improper metabolic activity, or allergies, or cancer and mental illness as diabetes, haemophilia, leukemia, schizophrenia.

Immunisation: It means, we make the body immune to certain diseases by introducing respective weakened germs into the body. Thus we develop resistance to the concerned disease this process is called immunisation. The germs or the material introduced into the body to make it resistant to the concerned disease is called vaccine. This produces antibodies in the body of the person and the person can be saved by these antibodies. The vaccine can be given by the injection or orally as polio drops, tap vaccine for typhoid, BCG vaccine for tuberculosis.

Pathogens: The germs that cause diseases to human beings and to other animals and plants are called pathogens. They spread the diseases from person to person or through the air or through the articles of the diseased persons. Pathogens may be different kinds of bacteria, viruses, fungi, protozoans or worms.

Allergy: Allergy is an unpredictable reaction to a particular substance. This type of substance is called allergen. Different people are allergic to different substances. A few common allergens are dust, spores, pollen, certain clothes, particular cosmetics, etc. The common areas of the body parts which are affected by allergies are skin, respiratory and digestive tracts. Asthma, eczema, diarrhoea, vomiting, nausea, etc. are some of the common allergic reactions.

AID’S (Acquired Immune Deficiency Syndrome): It is a viral disease caused by the virus called HTV (Human immuno deficiency virus) This virus makes the defence mechanism of the human body very weak. The immune system in the body as W.B.C. becomes weak. Thus the person catches the infectious diseases very easily. This disease spreads through sexual contact as one of the partner may be carrier of the disease. It may spread through the blood transfusion and infected syringes, blades of the barbers, it may infect the developing baby through the blood by the mother. It is very deadly disease.

4. Fill in the blanks by selecting suitable words given below: (clotting, goitre, insuline, rickets, iron, proteins)

  1. Anaemia is caused due to the deficiency of iron
  2. Deficiency of Vit. D causes rickets in children.
  3. Deficiency of iodine in the diet may cause goitre.
  4.  Kwashiorkor is caused due to the deficiency of proteins
  5. Diabetes is caused due to undersecretion of insulin.
  6. Haemophilia is a disease caused due to slow clotting of the blood.

5. Find the odd one out:

(a) Typhoid, cholera, aundice, tuberculosis, tetanus.
Ans. Jaundice is odd one

(b) Cold, malaria, measles, mumps.
Ans. Malaria is odd one.

(c) Scurvy, rickets, polio, pellagra, nightblindness.
Ans. Haemophilia is odd one.

(d) Proteins, carbohydrates, fats, minerals, cancer.
Ans. Cancer is odd one.

6. Fill in the blank in the following table:
Selina Concise Biology Class 6 ICSE Solutions - Health and Hygiene 1
Answer:
Selina Concise Biology Class 6 ICSE Solutions - Health and Hygiene 2

7. Given below is a crossword puzzle. Read the clues across and clues down, and fill up the blank squares. Check up your performance with the correct solution given at the end.
Clues across
1. Category of pathogen that causes diseases, like common cold and mumps.
5. This is the vaccine for preventing tuberculosis.
6. An organ usually affected by tuberculosis.
7. Jumbled spelling of one of the most common insect which visits our exposed foods and contaminates them.
8. Cover this part of your body by a handkerchief while sneezing to prevent droplet infection to others.
9. These may readily grow in your hair, if you do not wash it regularly.
10. A disease that weakens body’s defence system against infections.
Selina Concise Biology Class 6 ICSE Solutions - Health and Hygiene 3
Answer:
Clues down

  1. Germ or germ-substance introduced into the body to prevent occurrence of an infectious disease.
  2. A disease caused by an infected dog, and which affects the central nervous system.
  3. A disease in which the eyes, the skin and the urine turn yellow.
  4. The disease pertussis is popularly known as whooping

Selina Concise Biology Class 6 ICSE Solutions - Health and Hygiene 4

Long Answer Questions
Question 1.
Describe the ways in which communicable diseases are transmitted through various indirect methods.
Answer:
Indirect methods of transmission of communicable diseases:

  1. Using items used by the infected persons:
    The healthy persons may be infected by using the articles like towel, hankey, utensils, bedding used by the patient infected by the communicable diseases. Diseases like tuberculosis, ring worm, common cold, influenza are transmitted by this method.
  2. Contaminated food and water:
    Diseases like dysentery, cholera spread through the contaminated food and water. Flies sitting on the food, if taken by a healthy person may be infected by the germs which may cause vomiting and loose motions. Similarly water and food infected by entamoeba may cause dysentery to persons who may take contaminated food.
  3. Vectors or carriers: Organisms like mosquitoes and house flies, ticks carry germs from the source of infection and pass on the germs to the normal persons and thus they are infected by diseases like malaria, cholera, plague. These organisms which cany the disease are called vectors and are not infected themselves.Mosquitoes suck blood and carry the disease causing protozoans from infected persons to healthy persons. Similarly houseflies carry the germs from garbage and sewage to the food. If this food is taken by the persons they become prey to typhoid and other diseases.
  4. Air: One sneeze from a person infected by cold may give billions of germs which are carried by air and may infect the healthy person. Tuberculosis passes from one person to other by coughing or sneezing of the infected person.These germs remain suspended in the air and persons may be infected by these spores or germs. Common cold, measles, diptheria, chicken pox.

Question 2.
List 3 ways by which you should keep your environmentclean.
Answer:
We should keep our environment clean in following ways:
Cleanliness of Environment:

  1. Maintain a clean environment to prevent the spreading of diseases due to the breeding of mosquitoes, house flies and microorganisms.
  2. Garbage should be kept in covered bins so that flies do not breed on it.
  3. Do not allow water to stagnate outside your house and in your neighbourhood. All the drains should also be covered. This will prevent breeding of mosquitoes.

Question 3.
cine’s are prepared, giving the name of one disease for which each type of vaccine is used.
Answer:
For developing resistance in the body we introduce germs or germ substances in the body to develop resistance in the body against a particular disease. The material introduced into the body is called vaccine, this practice is called prophylaxis. The germ or the germ substance is put into the body orally as polio drops or it is introduced by injection as TAB vaccine. Vaccine or vaccination was attached with small pox, but it is now used in a general sense.
Preparation: 

  1. Killed germs are introduced into the body These act as vaccine for TAB, vaccine for typhoid, Salk’s vaccine for poliomyelitis. Rabies vaccine for dog bite.
  2. Living weakened germs: The living germs are treated in such a way that they become very weak and as such, they cannot cause the disease. They can induce antibody formation such as the vaccine for measles and the freezed dried BCG vaccine for tuberculosis.
  3. Living fully virulent germs: These virulent germs in small doses are introduced into the body as vaccine and these produce antibodies in the body and these do not allow the germs of particular type to cause that disease. In this vaccination the person is inoculated with cowpox virus. It is very similar to small pox virus.
  4. Toxoids: Toxoids are prepared from the extracts of toxins secreted by bacteria. These toxins are poisons and these are made harmless by adding formalin into them. They retain their capacity and as a result when introduced into the body they produce antibodies into the body and do not allow the germs to grow in the body as vaccines for diphtheria and tetanus.