Reproduction in Animals Class 8 Science Extra Questions and Answers
Reproduction in Animals Class 8 Science Chapter 9 Extra Questions with Answers are provided here. We prepared these extra questions based on the latest NCERT Class 8 Science Book. CBSE Class 8 Science Chapter 9 Reproduction in Animals Extra Questions will help you to properly understand a particular concept of the chapter.
Class 8 Science Chapter 9 Reproduction in Animals Extra Questions
Very Short Answer Type Question
Question 1: Name two animals which reproduce sexually.
Answer: Cow, Elephant
Question 2: Name two animals which reproduce asexually.
Answer: Hydra, Amoeba
Question 3: Which type of reproduction involves gametes?
Answer: Sexual reproduction
Question 4: Which type of reproduction does not involve gametes?
Answer: Asexual reproduction
Question 5: What is another term for a fertilised egg?
Answer: Zygote
Question 6: Name the reproductive process which involves two parents.
Answer: Sexual reproduction
Question 7: Name the reproductive process which involves one parent.
Answer: Asexual reproduction
Question 8: What type of fertilization takes place in hen?
Answer: Internal fertilization takes place in hen.
Question 9: Name the organs which produce sperms in human.
Answer: The testes produce sperms in human.
Question 10: What are the male gametes in humans called?
Answer: The male gametes in humans are called sperms.
Question 11: What are the female gametes in humans called?
Ans. Female gametes in humans are called ova (eggs).
Question 12: Name the organs which produce female gametes.
Answer: Ovaries produce female gametes.
Question 13: Name the parent sheep of which dolly was a clone.
Answer: Finn Dorsett sheep
Question 14: Where does a fertilized egg (or zygote) develop into a baby?
Answer: A fertilized egg (or zygote) develops into a baby in the uterus.
Question 15: What are the reproductive organs of male?
Answer: The reproductive organs in male include testes, sperm ducts and penis.
Question 16: What term is used for bulges observed on the sides of the body of hydra?
Answer: Buds
Question 17: What is the name given to the fusion of male and female gametes?
Answer: Fertilization is the name given to the fusion of male and female gametes.
Question 18: What are the reproductive organs of female?
Answer: The reproductive organs in the female include ovaries, oviducts and uterus.
Question 19: What is foetus?
Answer: The stage of the embryo in which all the body parts can be identified is called a foetus.
Question 20: In which female reproductive organ does the embryo get embedded?
Ans. The embryo gets embedded in the wall of the uterus for further development.
Short Answer Type Questions
Question 1: What type of asexual reproduction take place in amoeba?
Answer: Amoeba reproduces by the common asexual reproduction method called binary fission.
Question 2: Who cloned Dolly the sheep?
Answer: Dolly was cloned by Ian Wilmut and his colleagues at the Roslin Institute in Edinburgh, Scotland.
Question 3: What purpose does the tail in a sperm serve?
Answer: Tail allows the sperm to become motile, hence helps the sperm to reach female gametes for fusion.
Question 4: What is cloning?
Answer: Cloning is the production of an exact copy of a cell, any other living part, or a complete organism.
Question 5: What are the two modes of reproduction in animals?
Answer: There are two modes by which animals reproduce. These are: (i) Sexual reproduction, and (ii) Asexual reproduction.
Question 6: What are the reproductive organs in humans which produce the gametes?
Answer: The ovary produces female gametes called ova and the testes produce male gametes called sperms.
Question 7: Which life process ensures that a plant or animal species will not disappear from the earth?
Answer: Reproduction is the life process ensures that a plant or animal species will not disappear from the earth.
Question 8: Explain the importance of reproduction in organisms.
Answer: Reproduction is essential for the continuation of a species. It ensures the continuation of similar kinds of individuals, generation after generation.
Question 9: What is an embryo?
Answer: The zygote divides repeatedly to give rise to a ball of cells. The cells then begin to form groups that develop into different tissues and organs of the body. This developing structure is termed as an embryo.
Question 10: Name the technique which is used to help a woman with blocked oviducts to have a baby.
Answer:. IVF or in vitro fertilization (fertilization outside the body) is the technique which is used to help a woman with blocked oviducts to have a baby.
Long Answer Type Questions
Question 1: Describe the process of fertilization in human beings.
Answer: The first step in the process of reproduction is the fusion of a sperm and an ovum. When sperms come in contact with an egg, one of the sperms may fuse with the egg. Such fusion of the egg and the sperm is called fertilization. During fertilization, the nuclei of the sperm and the egg fuse to form a single nucleus. This results in the formation of a fertilized egg or zygote.
Question 2: How does a hydra reproduce?
Answer: Hydra reproduces asexually by the process of budding. A small outgrowth called ‘bud’ is formed on the side of its body. This bud then grows gradually to form a small hydra. And finally the tiny new hydra detaches itself from the body of parent hydra and lives as a separate organism.
Question 3: Give two differences between a zygote and a foetus.
Answer: Differences between a zygote and a foetus
A zygote | A foetus |
1. The fusion of ovum and sperm is called fertilization. The fertilized egg is called a zygote. | 1. The stage of the embryo in which all the body parts are identifiable is called foetus. |
2. A zygote is a single cellular. | 2. A foetus is a multicellular. |
Question 4: Give two differences between zygote and embryo.
Answer: Differences between zygote and embryo
Zygote | Embryo |
1. The fusion of ovum and sperm is called fertilization. The fertilized egg is called a zygote. | 1. The zygote divides repeatedly to give rise to an embryo. |
2. A zygote is a single cellular. | 2. An embryo is a multicellular. |
Question 5: Why do fish and frogs lay eggs in hundreds?
Answer: Though these animals lay hundreds of eggs and release millions of sperms, all the eggs do not get fertilized and develop into new individuals. This is because the eggs and sperms get exposed to water movement, wind and rainfall. Also, there are other animals in the pond which may feed on eggs. Thus, production of large number of eggs and sperms is necessary to ensure fertilization of at least a few of them.
Question 6: Explain how chicks are born.
Answer: Internal fertilization takes place in hens also. Soon after fertilization, the zygote divides repeatedly and travels down the oviduct. As it travels down, many protective layers are formed around it. The hard shell that we see in a hen’s egg is one such protective layer. After the hard shell is formed around the developing embryo, the hen finally lays the egg. The embryo takes about 3 weeks to develop into a chick.
Question 7: Define asexual reproduction. Describe two methods of asexual reproduction in animals.
Answer: The type of reproduction in which only a single parent is involved is called asexual reproduction. The two methods of asexual reproduction in animals are:
Budding – In this type of asexual reproduction, a small part of the body of the parent organism grows as a ‘bud’ which then detaches and becomes a new organism. Example- hydra
Binary fission – In this type of asexual reproduction, the parent organism splits (or divides) to form two new organisms. Example – Amoeba reproduces by binary fission by dividing itself into two parts.
Question 8: Differentiate between Viviparous and Oviparous Animals.
Answer: Difference between Viviparous and Oviparous Animals
Viviparous Animals | Oviparous Animals |
The animals which give birth to young ones are called viviparous animals. | Those animals which lay eggs are called oviparous animals. |
Examples of viviparous animals are cow, dog, cat, lion, tiger, horse, rabbit etc. | Examples of oviparous animals are butterfly, frog, fish, crow, sparrow, snake, lizard, ostrich etc. |
Question 9: What is the basic difference between asexual and sexual reproduction?
Answer: Difference between asexual and sexual reproduction
Asexual reproduction | Sexual reproduction |
1. The type of reproduction in which only a single parent is involved is called asexual reproduction. | 1. Reproduction resulting from the fusion of male and female gametes is called sexual reproduction. |
2. No formation or fusion of gametes occurs. | 2. Gametes are always formed, and fusion also occurs. |
3. No fertilization takes place. | 3. Fertilization takes place. |
Question 10: Differentiate between internal fertilization and external fertilization.
Answer: Difference between internal fertilization and external fertilization
Internal fertilization | External fertilization |
1. Fertilization which takes place inside the female body is called internal fertilization. | 1. Fertilization that takes place outside the female body is called external fertilization. |
2. This is observed in human beings and other animals such as hens, cows and dogs. | 2. This is observed in frogs, fish, starfish, etc. |
Question 11: What is metamorphosis? Give examples.
Answer: The transformation of the larva into adult through drastic changes is called metamorphosis. Commonly known examples of metamorphosis include the process undergone by most insects and the transformation of tadpoles into frogs. The diagram below shows the stages of this change, wherein the small fish-like tadpoles transform into what seems a completely different animal:
Question 12: How does fertilization take place in frog?
Or
How do frog eggs get fertilized?
Or
How does fertilization occur in frog?
Answer: During spring or rainy season, frogs and toads move to ponds and slow flowing streams. When the male and female come together in water, the female lays hundreds of eggs. Frog’s egg is not covered by a shell and it is comparatively very delicate. A layer of jelly holds the eggs together and provides protection to the eggs. As the eggs are laid, the male deposits sperms over them. Each sperm swims randomly in water with the help of its long tail. The sperms come in contact with the eggs. This results in fertilization.
Question 13: What is ‘in vitro fertilization’ technique of reproduction?
Or
What are test-tube babies?
Answer: In some women oviducts are blocked. These women are unable to bear babies because sperms cannot reach the egg for fertilization. In such cases, doctors collect freshly released egg and sperms and keep them together for a few hours for IVF or in vitro fertilization (fertilization outside the body). In case fertilization occurs, the zygote is allowed to develop for about a week and then it is placed in the mother’s uterus. Complete development takes place in the uterus and the baby is born like any other baby. Babies born through this technique are called test-tube babies.
Question 14: How could a single cell become such a big individual?
Answer: Fertilization results in the formation of zygote. The zygote divides repeatedly to give rise to a ball of cells. The cells then begin to form groups that develop into different tissues and organs of the body. This developing structure is termed an embryo. The embryo gets embedded in the wall of the uterus for further development. The embryo continues to develop in the uterus. It gradually develops the body parts such as hands, legs, head, eyes, ears, etc. The stage of the embryo in which all the body parts can be identified is called a foetus. When the development of the foetus is complete, the mother gives birth to the baby.
Question 15: What are the steps involved in sexual reproduction in animals?
Answer: Steps involved in sexual reproduction in animals are:
- The male parent produces male gametes called sperms. Sperm is a single cell with all the usual cell components.
- The female parent produces female gametes called eggs (or ova). Like the sperm, an egg is also a single cell.
- The sperm enters into the egg. The nucleus of sperm fuses with the nucleus of egg cell to form a new cell called zygote.
- The zygote divides repeatedly to form a hollow ball of hundreds of cells which is called embryo.
- Embryo grows and becomes a foetus in which all main body features of the baby animal have formed.
- Foetus grows and develops to form a new baby animal.
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