Class 8 Science

NCERT Solutions For Class 8 Science Chapter 7 Reaching The Age Of Adolescence Multiple Choice Questions

Question 1. Which endocrine gland is attached to the brain?

1. Adrenal
2. Pancreas
3. Pituitary
4. Thyroid

Answer: 3. Pituitary

NCERT Class 8 Science Chapter 7 Reaching the Age of Adolescence MCQs

Question 2. Which choice appropriately distinguishes the roles of oestrogen and insulin?

1. Oestrogen plays a role in the development of mammary glands, while insulin helps to control blood sugar levels
2. Oestrogen plays a role in promoting the growth of facial hair, while insulin helps to control blood sugar levels
3. Oestrogen helps to control blood sugar levels, while insulin plays a role in promoting the growth of facial hair
4. Oestrogen helps to control blood sugar levels, while insulin plays a role in the development of mammary glands

Answer: 1. Oestrogen plays a role in the development of mammary glands, while insulin helps to control blood sugar levels

Question 3. The faulty functioning of an endocrine gland can make a person very short or very tall. This gland is

1. Thyrouid
2. Pituitary
3. Adreied
4. Pancreas

Answer: 2. Pituitary

NCERT Solutions for Reaching the Age of Adolescence Chapter 7

Question 4. What are the consequences of drug addiction?

1. They can harm our body
2. They can protect our body from infections
3. They can enhance the body’s immunity
4. They can make our body resistant to harmful organisms

Answer: 1. They can harm our body

Question 5. AIDS can spread from an infected person to another person through

1. Sharing food
2. Blood transfusion
3. Sharing comb
4. A mosquito bite

Answer: 2. Blood transfusion

Assessment Exercise Multiple Choice Questions

Question 6. What physiological changes take place in females during puberty?

1. Development of a large voice box
2. Development of hair on the face and chest
3. The region below the waist becomes wider
4. Shoulder broaden

Answer: The Region below the waist becomes wider

Question 7. During puberty, hormones are produced. What secondary sexual characteristics typically emerge when testosterone is released in males?

1. High-pitched voice
2. Development of Adam’s apple
3. Development of mammary glands
4. Growth of hair on the head

Answer: Development of Adam’s apple

Reaching the Age of Adolescence MCQs Class 8 NCERT Solutions

Question 8. Which of the following options correctly describes women’s menstrual cycle?

1. The release of the fertilised egg from the uterus that occurs once a month
2. The release of the unfertilised egg from the uterus that occurs once in 28-30 days
3. The release of the unfertilised egg from the ovary that occurs once in 28-30 days
4. The release of the fertilised egg from the ovary that occurs twice in a month

Answer: The release of the unfertilised egg from the ovary that occurs once in 28-30 days

Question 9. What would likely be the gender of a child if a sperm with Having Y chromosome fertilised an egg?

1. A boy, as the unfertilised egg has one X chromosome
2. A girl, as the unfertilised egg has one Y chromosome
3. A girl, as the unfertilised egg has one X chromosome
4. A boy, as the unfertilised egg has one Y chromosome

Answer: A boy, as the unfertilised egg has one Y chromosome

MCQs for Reaching the Age of Adolescence Chapter 7 Class 8

Question 10. Which of the following is not a hormone?

1. Thyroxine
2. Insulin
3. Adrenal
4. Insect hormone

Answer: Adrenal

NCERT Class 8 Science Chapter 7 Reaching The Age Of Adolescence LAQs

Question 1. A few days back, Shradhaa, a student of class Vth, was driving a car. She went to a crop field. The road level was just above the level of the ploughed field. As she wanted to stop the slow-moving car, the brakes failed to work. Suddenly, she turned the car towards the ploughed field. After some time, the car came to rest.

1. Shradha turned the car towards the ploughed field. Explain why?
Answer:

She turned her car towards the ploughed field to protect herself from an accident.

NCERT Solutions for Friction LAQs Class 8

2. Explain how the car came to rest after covering some distance in the ploughed field.
Answer:

The car moved from the road to the ploughed field, so the force of friction between the tyre and the ground surface suddenly increased. Because the large number of irregularities reduces the movement of the tyre. Thus, the car came to a rest.

3. Mention the values that Shradha exhibits here.
Answer: The values displayed by Shradha are intelligence and awareness.

Question 2. In a Physics classroom, a teacher told to his students that when a cricket player wants to catch a ball then he first rubs his hands. Thus, there is less chance of slipping the ball from the hands.

1. Explain the reason for not slipping of ball from the hand.
Answer:

The player rubs his hand, due to which the palms become warm which absorbing the moisture from the surface and making the surface rough. So, due to the roughness of the hands, the ball may get a better grip between the hands and will not slip.

NCERT Solutions for Class 8 Science Friction LAQs

2. If the player makes his hands oily instead of rubbing them, would he be able to catch the ball?
Answer:

The player makes the palm surface oily. The number of irregularities decreases, and the surface becomes smooth. So, the ball slips off easily from the hand.

3. Mention the type of teaching skills of the teacher that is being represented here.
Answer:

As, teacher wants to teach the students through easy examples. So, this act of teaching shows the experience and ideality of the teacher.

Question 3. Explain with the help of an example that heat is produced by friction.
Answer:

As friction opposes the relative motion between the two surfaces, it produces heat. So, when we rub our hands together vigorously for a few minutes, we feel heat. Similarly, when we strike a matchstick against the rough surface, it catches fire.

NCERT Solutions for Friction Chapter 9 LAQs

Question 4. We have two identical metal sheets. One of them is Tube 3 Tube 4 rubbed with sandpaper, and the other with ordinary paper. The one rubbed with sandpaper shines more than the other. Give a reason.
Answer:

While rubbing with sandpaper, more frictional force is produced between the layers of the metal sheet and sandpaper, which causes more force on the dust particles, and they are removed easily, so it will shine more. But in the case of ordinary paper, the force of friction is not sufficient to remove all the dust, so it will shine less in this case.

Question 5. Friction is In force that acts betweenn two surfaces that slide across one another. It is net in the opposite direction in which the object is moving. Friction is the cause of it both in and out. It prevents our shoes from slipping on the footpath when we walk, but sometimes it may also harm us. It reduces the efficiency of a machine. There isn’t a lot of energy loss due to friction. Friction enn bo produced by some methods. For example, we use lubricants like oil, grease to reduce the friction between the moving parts of n machine. In many machines, friction is reduced by using ball bearings.

1. Which of the following can be used as a lubricant?

1. Mustard oil
2. Soil
3. Paper
4. Iron powder

Answer: 1. Mustard oil

2. Friction always acts in which direction that to the moving body.

1. Perpendicular
2. Same direction
3. Opposite direction
4. Always downward

Answer: 3. Opposite direction

NCERT Class 8 Science Chapter 9 Friction LAQs

3. Friction can be increased by using

1. Lubricant
2. Chalk powder
3. Oil
4. Talcum powder

Answer: 2. Chalk powder

NCERT Solutions For Class 8 Conservation Of Plants And Animals Multiple Choice Questions

Question 1. A tiger reserve is a forest area where the tiger population is protected. Why did the Indian government declare parts of many forests as tiger reserves?

1. Tigers is a mammals
2. The tiger is our national animal
3. Tiger is an endangered species
4. Tiger is the top predator of the forest ecosystem

Answer: 3. The Tiger is an endangered species

Question 2. Which statement is incorrect about endangered species?

1. Their number has decreased drastically
2. They might become extinct shortly
3. They pose a danger to other animals
4. Their natural habitat needs to be protected

Answer: 3. They pose a danger to other animals

NCERT Class 8 Science Chapter 5 Conservation of Plants MCQs

Question 3. Wild buffalo is an endangered species because

1. Its population is diminishing
2. It has become extinct
3. It Is found exclusively in a particular area
4. Poaching is strictly prohibited

Answer: 1. Its population is diminishing

Question 4. Snakes are killed in large numbers because

1. They Arc Very Poisonous
2. They Kill Rats
3. Their Skin Is Expensive
4. They Damage The Crops

Answer: 3. Their Skin Is Expensive

Question 5. The Red Data Book keeps a record of all the

1. Endemic species
2. Extinct species
3. Endangered plant
4. Endangered animals

Choose the correct option 

1. (1)and(2)
2. (2) and (3)
3. (3) and (4)
4. (1) and (4)

Answer: 3. (3) and (4)

NCERT Solutions for Conservation of Plants Chapter 5

Question 6. The migratory birds come to India every year in winter for a few months.

1. To escape the severe summer
2. To escape the severe winter
3. To escape the heavy rains
4. To escape from predators

Answer: 2. To escape the severe winter

Question 7. Why should we recycle paper?

1. Paper is biodegradable
2. Recycled paper is stronger
3. Production of paper requires a lot of wood pulp
4. Recycling of paper produces useful by-products

Answer: 3. The Production of paper requires a lot of wood pulp

Class 8 Chapter 5 Conservation of Plants Multiple Choice Questions

Question 8. What kind of approach should one take to lessen deforestation?

1. Limiting the use of paper
2. Using only fine-quality paper for work
3. Throwing old newspapers in the dustbins
4. Bury the used and waste paper instead of burning it

Answer: 1. Limiting the use of paper

Question 9. Planting new trees is called

1. Species
2. Deforestation
3. Desertification
4. Reforestation

Answer: 4. Reforestation

Question 10. What is expected to be accomplished by planting trees in the forest?

1. Conservation of forests and animals
2. Increase in the number of extinct species
3. A decrease in the number of predator species
4. Availability of more information for the Red Data Book

Answer: 1. Conservation of forests and animals

Question 11. Which term is used for the species that are found only in a particular area?

1. Extinct
2. Endemic
3. Endangered
4. Threatened

Answer: 2. Endangered

NCERT Solutions for MCQs on Conservation of Plants

Question 12. Which of these books keeps a record of all the endangered animals and plants?

1. Red Data Book
2. Blue Data Book
3. Black Data Book
4. Green Data Book

Answer: 1. Red Data Book

Question 13. Which of the following is not true regarding deforestation?

1. Causes soil erosion
2. Causes a decrease in temperature
3. Causes global warming
4. Causes drought

Answer: 2. Causes a decrease in temperature

Question 14. Animals whose numbers are diminishing to the level that they might face extinction are known as

1. Endemic
2. Endangered
3. Extinct
4. Fauna

Answer: 2. Endangered

NCERT Class 8 Conservation of Plants Chapter 5 MCQs

Question 15. Choose the factors that prove that if not taken care the endemic species may vanish shortly.

1. Increasing population
2. Destruction of habitat
3. Introduction of new species
4. All of the above

Answer: 4. All of the above

NCERT Solutions For Class 8 Science Chapter 9 Friction Multiple Choice Questions

Question 1. Treads are made in the tyres to

1. Increase Friction
2. Decrease Friction
3. Speed Up The Vehicle
4. Speed Down The Vehicle

Answer: 1. Increase Friction

NCERT Solutions for Friction MCQs Class 8

Question 2. In a large commercial complex, there are four ways to reach the main road. One of the paths has loose soil, the second is laid with polished marble and the third is laid with bricks, and the fourth has a gravel surface. It is raining heavily and Paheli wishes to reach the main road. The path on which she is least likely to slip is

1. Loose Soil
2. Bricks
3. Polished Marble
4. Gravel

Answer: 4. Gravel

NCERT Solutions for Class 8 Science Friction MCQs

Question 3. Which of the following statements is Incorrect?

1. Friction acts on a ball rolling along the ground.
2. Friction acts on a boat moving on water.
3. Friction acts on a bicycle moving on a smooth road.
4. Friction does not act on a ball moving through the air.

Answer: 4. Friction does not act on a ball moving through air.

Question 4. Whenever the surfaces in contact tend to move or move to each other, the force of friction comes into play

1. Only if the tire objects are solid
2. Only if one of the two objects is liquid
3. Only if one ofthe two objects is gaseous
4. Irrespective ofwhether the objects are solids, liquids, or gases

Answer: 4. Irrespective of whether the objects are solids, liquids, or gases

NCERT Class 8 Science Chapter 9 Friction MCQs

Question 5. The fish swim easily in the water because they have

1. More energy
2. Streamlined shape
3. Both (1) and (2)
4. None of these

Answer: 2. Streamlined shape

Friction In Daily Life Class 8 Science  Multiple Choice Questions

Question 6. The direction of friction is always

1. Opposes the motion
2. Direction of motion
3. Perpendicular to the motion
4. None of the above

Answer: 1. Opposes the motion

NCERT Solutions for Friction Chapter 9 MCQs

Question 7. Which of the following devices is used to measure the force acting on an object?

1. Spring balance
2. Odometer
3. Both (a) and (b)
4. None of the above

Answer: 1. Spring balance

Question 8. Which of the following does not reduce friction?

1. Streamlined shape
2. Lubricant
3. Sand
4. Oil

Answer: 3. Sand

Friction Class 8 NCERT MCQs

Question 9. The frictional force exerted by fluids is also known as

1. Drag
2. Static Friction
3. Rolling Friction
4. Sliding Friction

Answer: 1. Drag

NCERT Solutions For Class 8 Science Chapter 7 Reaching The Age Of Adolescence LAQs

Question 1. Rohan and Seema were childhood friends. When Seema became eleven years old, her breasts started developing. Rohan’s voice became deeper, his shoulders and chest became wider.
Answer:

1. Give a word for the characteristics that are developed in Rohan and Seema.
Answer:

Both Rohnn and Seema have developed secondary sexual characteristics,

NCERT Class 8 Science Chapter 7 Reaching the Age of Adolescence LAQs

2. Name the hormone that is responsible for these sexual characteristics in Seema.
Answer:

Oestrogen is the hormone responsible for these sexual characteristics in Seema.

3. After a few years, Rohan observed a bulge in ills neck. What could be the possible reason for tills bulge in his neck?
Answer:

The bulge in Rohan’s neck is called Adam’s apple, which is formed because the male larynx grows bigger during puberty.

Question 2. Sanjay and Seoma were childhood friends. When Soenia became 12 years old, she developed a little swelling in her neck. She visited a doctor who prescribed some medicines and asked her to take an iodine-rich diet. After some time, she felt better. Later, her friend Sanjay also developed a little protrusion on his throat. He got worried. But when he went to the doctor, he assured him that it was normal. It was just the development of secondary sexual characteristics in him.
Answer:

1. Describe briefly the meaning of ‘secondary sexual characteristics’.
Answer:

The external characters that distinguish a male from a female are called secondary sexual characteristics. For example, the development of the breast in girls and the growth of moustaches in boys.

NCERT Solutions for Reaching the Age of Adolescence Chapter 7

2. Explain the change that Sanjay was experiencing.
Answer:

Sanjay was experiencing the enlargement of the voice box. The growing voice box in boys can be seen as a protruding part of the throat.

3. Recommend any two measures to Sanjay and Seema to maintain their reproductive health during adolescence.
Answer:

The measures that can be taken to maintain their reproductive health are as follows

1. Maintain personal hygiene
2. Take a balanced and nutritious diet

Question 3. When Sudlia reached a certain age tho vaginal bleeding started occurring after regular Interval of time. Her mother told her to take special care of her hygiene during this period.
Answer:

1. Name the process occurring after regular intervals.
Answer:

This process is known as menstruction

2. What does the onset of this process in females signify?
Answer:

The one set of menstruation signifies that the reproductive system of a female has started working

Class 8 Chapter 7 Reaching the Age of Adolescence Long Answer Questions

3. Give the reason why her mother told her to take special care of her hygiene during this period
Answer:

Her mother told her to take special care of her hygiene during this period because if it is maintained, there might be chances of not the occurrence of bacterial infections.

4. Shobha gave birth to a healthy baby girl. Her husband was unhappy with the news and held her responsible for the baby to do a girl. Was her husband just a flood of blaming her for the birth of a baby girl?
Answer:

No husband was not justified in blaming his Wife for the birth of a baby. As the unfertilized egg of a female always has one

1. Draw a diagram to show how the sex of a fetus is determined.
Answer:

Mother- XX Father – XY

Question 4. Observe the chart and graph given in the figure carefully and answer the following questions.

1. Which of the lines represents the height of boys?
2. Which line represents the height of girls?
3. What is the difference between the pattern of Increase in the height of boys and girls?
4. Is this pattern true for each individual?

Answer:

1. The dotted line represents the height of boys.
2. The solid line represents the height of girls.
3. At the onset of puberty, girls grow faster in height than boys, and by the age of 18 years, both reach their maximum height.
4. No, the rate of growth in height varies among individuals. Some may grow in height suddenly at puberty and then slow down, while others may grow gradually.

NCERT Solutions for LAQs on Reaching the Age of Adolescence

Question 5. Our government has legalised the age for marriage for boys and girls. Give reasons as to why one should get married after a certain age.
Answer:

In our country, the legal age for marriage is 18 years for girls and 21 years for boys. This is because teenage mothers are not prepared mentally or physically for motherhood.

Early marriage and motherhood cause health problems for both the mother and the child. It also curtails employment opportunities for the young woman and may cause mental agony as she is not ready to shoulder the responsibilities of motherhood.

Also, boys before that age may not be mentally mature and financially secure enough to take on the responsibilities of a family. Thus, one should get married only after a certain age.

NCERT Solutions For Class 8 Science Chapter 10 Sound: Very Short Answer Questions

Question 1. How is the blind folded person able to guess which player is nearer to her?
Answer: The vibration due to the movement of a closer player is more than others, and the blind folded person can easily imagine in which direction a player is nearer to her.

NCERT Solutions for Sound VSAQs Class 8

Question 2. Briefly mention the experience when you touch a sound-producing school bell.
Answer: When we touch a sound-producing school bell, we feel the vibration in it.

Question 3. How does the sound propagate?
Answer: Sound needs a medium for propagation.

Question 4. Is it possible that the decreasing amount of air in the tumbler had something to do with the decreasing loudness of the ring?
Answer: Yes, if the amount of air starts decreasing in the tumbler, then the loudness of the ring also decreases.

Question 5. Does sound travel in liquids?
Answer: Yes, sound can travel through liquids.

NCERT Solutions for Class 8 Science Sound VSAQs

Question 6. Can you say that sound can travel through strings?
Answer: Yes, Sound can travel through strings.

Question 7. How can we hear sound through solids, liquids, and gases?
Answer: Sound travels faster in solids compared to liquids and gases because the particles in solids are much closer together than in liquids and gases.

Question 8. If an object oscillates 20 times in 1s, what would be its frequency?
Answer: As we know, the frequency is the total number of oscillations in 1 s. So, the frequency will be 20 Hz.

Question 9. How is it possible that you can recognise many familiar sounds without seeing the objects producing them?
Answer: We can recognise many familiar sounds of objects without seeing them because different objects produce different sounds.

NCERT Solutions for Sound Chapter 10 VSAQs

Question 10. What factors make the sound differ from each
Answer: Amplitude and frequency

Question 11. Is there any difference between the sound of a baby and that of an adult?
Answer: Yes, the frequency of the sound of a child is higher than that of an adult.

Question 12. Why is your voice different from that of your teacher?
Answer: This is because of the sound.

Question 13. Can we hear the sound of all vibrating bodies?
Answer: A sound is audible to us only if the sound produced by the vibrating body is in the audible range, i.e., 20 Hz to 20 kHz.

Class 8 Science Chapter 10 Sound Very Short Answer Questions

Question 14. Is the sound always pleasing?
Answer: No

Question 15. Can you list some sources of noise pollution?
Answer: Sounds of vehicles, bursting crackers, loudspeakers, etc.

Question 16. Name the sources in the home that may lead to noise.
Answer: The sources that may lead to the noise are transistors, radio at high volume, television, desert coolers, air conditioners, etc.

Sound Class 8 VSAQs and Answers

Question 17. How can the noise pollution be controlled in a Residential area?
Answer: The following steps should be taken to control noise pollution in a residential area

1. The television and loudspeaker should be run at low volumes.
2. Silencing devices must be installed in the transport vehicles, like tractors, trucks, etc.
3. Industries should be set up away from the residential areas.

NCERT Solutions For Class 8 Science Chapter 7 Reaching The Age Of Adolescence SAQs

Question 1. Who should be involved Inking modelclnos/drug unions prescribed by n doctor? Give Ronsons.
Answer:

We should avoid hiking medications/drugs unless prescribed by a doctor because several medicines have adverse side effects and have specific dosage levels, which, if not followed, may harm the body. Drugs can be addictive too and can ruin our health and happiness.

Question 2. Given below are certain food Items required for proper nourishment of the child, cents. Name the nutrients present in the food Items and write their functions.
Answer:

Reaching the Age of Adolescence Class 8 SAQs

Question 3. Paheli and Boojho realised that a sudden increase in height and the hairy line above the lips in boys were signs of adolescence. They wanted to know about other changes at puberty.
Answer:

The other changes in the body are as follows

1. Change in body shape.
2. Increase in height.
3. Increased activity of sweat and sebaceous glands.

Question 4. Paheli and Boojho have now understood that puberty marks the beginning of the reproductive period when one becomes capable of reproduction. But they want to know if reproductive life once begins, it continues, or it ends sometime.
Answer:

The capacity for maturation and production of gametes lasts for a much longer time in males than in females. In females, the reproductive phase of life begins at puberty (10 to 12 years of age) and generally lasts till the age of approximately 45 to 50 years.

NCERT Solutions for Reaching the Age of Adolescence Chapter 7

Question 5. List changes in the body that take place at puberty.
Answer: At puberty, the body undergoes the following changes

• Bow and girls become capable of reproduction
• Sudden increase in height.
• Broad shoulders and wide chests in boys, and the region below the waist becomes wider in girls.
• Growth of hair on different parts of the body.
• The voice of girls becomes high-pitched, and that of boys becomes deep.
• Secretions of sweat and sebaceous glands increase.
• Sex organs become active. In boys, the testes start to form sperm, and in girls, the ovaries enlarge and eggs begin to mature.
• Changes at the mental, intellectual, and emotional level.

Reaching the Age of Adolescence Class 8 SAQs

Question 6. Prepare a table having two columns depicting the names of endocrine glands and the hormones secreted by them.
Answer:

The table is shown below.

Class 8 Chapter 7 Reaching the Age of Adolescence Short Answer Questions

Question 7. What are sex hormones? Why are they named so? State their functions.
Answer:

The hormones that are responsible for the male and female secondary sexual characteristics are called sex hormones.

They are called sex hormones as they control the sexual activities and help us to distinguish boys from girls. In boys, sex hormones control the formation of sperm by the testes and the growth of facial hair, etc., and in girls, they help to develop breasts, control the menstrual cycle, etc.

NCERT Class 8 Chapter 7 Reaching The Age Of Adolescence VSAQs

Question 1. XX or XY, state the combination of sex chromosomes that produces a male child?
Answer: XY combination of sex chromosomes produces a male child.

Question 2. The nucleus of a cell contains chromosomes for inheritance. How many chromosomes are there in the nuclei of a human cell?
Answer: The nucleus of each human cell contains 23 pairs of chromosomes.

Question 3. Name the endocrine gland attached to the base of the brain.
Answer: Pituitary gland.

Question 4. Name some endocrine glands other than the pituitary gland.
Answer: Some endocrine glands other than the pituitary are the thyroid, pancreas, and adrenals.

Class 8 Science Reaching the Age of Adolescence very short answer questions

Question 5.  Boojho begins wondering how long this period marked by changes in the body would last.
Answer: The period marked by change, i.e. adolescence, begins around the age of 11 and lasts upto 18 or 19 years of age.

Question 6. Paheli, on the other hand, is worried about this period of life when you are neither a child nor an adult. She wondered whether this period between childhood and adulthood had a special name.
Answer: The period oflife between childhood and adulthood is termed adolescence.

Question 7. Both Boojho and Paheli wish to know what initiates changes at puberty.
Answer: The changes that occur at adolescence are controlled by hormones.

NCERT Solutions for Reaching the Age of Adolescence Chapter 7

Question 8. Pahell heard her mother and her aunt talking about her cousin who is going to have a baby. They were discussing whether she would give birth to a boy or a girl. She wonders what makes the fertilised egg develop into either a boy or a girl.
Answer: Inside the fertilised egg or zygote is the instruction for determining the sex of the baby. This instruction is present in the thread-like structures called chromosomes.

Question 8. Are there hormones in other animals also? Do they have any role to play in reproduction?
Answer: Yes, animals also have hormonal secretions. Yes, hormones have their role to play in reproduction.

Question 9. If people do not have enough iodine in their diet, will they get goitre caused by lack of thyroxine?
Answer: Yes, if people do not have enough iodine in their diet, they will get goitre caused by lack of thyroxine

VSAQs for Reaching the Age of Adolescence Chapter 7 Class 8

Question 10. What is the term used for secretions of endocrine glands responsible for changes taking place in the body?
Answer: Hormone is the term used for secretions of endocrine glands responsible for changes taking place in the body.

Question 11. Define adolescence.
Answer: Adolescence is the period of life in which organisms become reproductively active. In other words, it is the period of attaining reproductive maturity in boys and girls, which starts from 11-13 years and lasts upto 18-19 years in humans.

NCERT Class 8 Science Chapter 6 Reproduction In Animals Multiple Choice Questions

Question 1. Aquatic animals in which fertilisation occurs in water are said to be

1. Viviparous without fertilisation
2. Oviparous with external fertilisation
3. Viviparous with internal fertilisation
4. Oviparous with internal fertilisation

Answer: 2. Oviparous with external fertilisation

NCERT Class 8 Science Chapter 6 Reproduction in Animals MCQs

Question 2. Which is not an oviparous animal?

1. Hen
2. Frog
3. Butterfly
4. Dog

Answer: 4. Dog

Question 3. In the list of animals given below, the lion is the odd one out.

Human being, cow, dog, hen.

The reason for this is

1. It undergoes internal fertilisation
2. It is oviparous
3. It is viviparous
4. It undergoes external fertilisation

Answer: 2. It is oviparous

Question 4. Which of the following is not a viviparous animal?

1. Rat
2. Lizard
3. Rabbit
4. Cat

Answer: 2. Lizard

NCERT Solutions for Reproduction in Animals Chapter 6

Question 5. Tadpole is the larva of

1. Fish
2. Frog
3. Mosquito
4. Butterfly

Answer: 2. Frog

Question 6. Baby, before being born, is termed as

1. Embryo
2. Foetus
3. Zygote
4. Egg

Answer: 2. Foetus

Question 7. Reproduction by budding takes place in

1. Hydra
2. Moeba
3. Paramecium
4. Bacteria

Answer: 1. Hydra

MCQs for Reproduction in Animals Chapter 6 Class 8

Question 8. Reproduction by binary fission occurs in

1. Hydra
2. Amoeba
3. Cloning
4. Hatching

Answer: 2. Amoeba

Question 9. The production of an exact copy of an animal by asexual reproduction is known as

1. Budding
2. Mating
3. Cloning
4. Hatching

Answer: 3. Cloning

Question 10. Sexual reproduction begins with

1. Implantation
2. Fertilisation
3. Zygote formation
4. Development of the embryo

Answer: 2. Fertilisation

Question 11. The process of internal fertilisation differs from external fertilisation as

1. The fusion of sperm and ovum takes place inside the female body
2. Fusion of sperm and ovum takes place in the ovaries
3. Gametes are produced inside the bodies of the parents
4. Either of the gametes is released outside the body of the parents

Answer: 1. The fusion of sperm and ovum takes place inside the female body

NCERT Solutions for MCQs on Reproduction in Animals

Question 12. Which example correctly depicts the difference between a viviparous and an oviparous animal, respectively?

1. Cats directly give birth to a young one, while hens lay eggs
2. Frogs lay soft-shelled eggs, while birds lay hard-shelled eggs
3. Frogs lay unfertilized eggs in the water, while hens lay fertilised eggs
4. Dogs give birth to many puppies, while elephants give birth to just one calf

Answer: 1. Cats directly give birth to a young one, while hens lay eggs

Question 13. Select the animal which undergoes metamorphosis during its life cycle.

1. Dog
2. Cat
3. Hen
4. Tadpole

Answer: 4. Tadpole

Question 14. The multicellular organism which reproduces by budding is

1. Amoeba
2. Yeast
3. Paramecium
4. Hydra

Answer: 4. Hydra

NCERT Solutions For Class 8 Science Chapter 6 Reproduction In Animals Long Answer Questions

Question 1. How can we say that fish exhibit external fertilisation?
Answer:

Female fish lay eggs in water while male fish release sperm in water. Sperm swim and reach the eggs of fish randomly due to water currents. When a sperm comes in contact with the viable egg, nuclei of both cells fuse to form a zygote. This process of fertilisation takes place in water outside the female body, hence, fertilisation is external in fishes.

Question 2. Hens and frogs are both oviparous, exhibiting different types of fertilisation, explain.
Answer:

Hens lay eggs after fertilisation, therefore their eggs are covered with a hard shell to protect the young ones. This shows that fertilisation in a hen is internal. The frogs on the hand lay both sperm and eggs in winter water before fertilisation. Thus, the fertilisation in frogs takes place in water, hence it is external.

NCERT Class 8 Science Chapter 6 Reproduction in Animals LAQs

Question 3. The picture shows the basic parts of a salmon fish 
Answer:

Part ‘Z’, which represents the tail of the sperm, helps it to swim in water and reach the egg.

Which part of the sperm helps it to swim in water and reach the egg?
Answer:

Organ B is identified as the ovary

Question 4. Observe the diagram and answer the following questions

Answer: 1. Fallopian tube or oviduct.

1. Identify the organ B.

2. Whore does fertilisation occur In tho above diagram?

1. 1
2. 2
3. 3
4. 4

NCERT Solutions for Reproduction in Animals Chapter 6

Question 5. Observe the following figures.
Answer:

1. The figures showing stages during the development of the embryo are identified as

1. Identify the stages 1 to 4 in the figure during the development of the human baby.
Answer:

1. Embedding of the embryo in the uterus (implantation)

2. Arrange the stages in the correct sequence of development.
Answer: 2. Fertilisation (fusion of egg and sperm)

Reproduction in Animals Chapter 6 LAQs Class 8 NCERT

3. Explain the development that takes place in any one stage.
Answer:

3. Zygote formation and development of an embryo from the zygote.

The embryo, after being implanted in the uterus, continues to develop and differentiate into body parts. This stage of the embryo is termed as foetus. After the foetus is completely developed, the mother gives birth to the baby.