Reproduction in animals

Q1) what is reproduction

Ans: the process through which a living thing produces new living organisms like itself is called reproduction.

Q2) define asexual reproduction with an example.

Ans: in asexual mode of reproduction, only a single parent is involved in producing new organisms. There are different types of asexual reproduction.

Example: binary fission in amoeba.

Q3) name the organ that produces male gamete

Ans: testis  

Q4) which female organ produces egg cell

Ans: ovary

Q5) what are viviparous animals

Ans: animals which give birth to young ones.

Q6) name any three oviparous animals.

Ans: insects, reptiles and birds.

Q7) define metamorphosis.

Ans: in the case of insects like the butterfly there are intermediary stages of the caterpillar and the pupa. These stages undergo many bodily changes before the adult butterfly emerges. The drastic changes that take place in this process is called metamorphism.

Q8) how does fertilization take place in fish.

Ans: in many animals such as fish and frogs, fertilization takes place outside the body. The female animal releases eggs in the water. At the same time, the male releases sperms in the water and on reaching an egg, one of the sperms penetrates the egg and fertilizes it. The fertilized egg remains in the water and develops into a new individual.

Q9) list the male and female reproductive organs in humans.

Ans: testis and ovaries

Q10) What is a zygote?

Ans: the fertilization of the human egg cell by a sperm takes place in the Fallopian tube. The fertilized egg cell is called zygote.

Q11) Explain the importance of reproduction in living things.

Ans: reproduction allows organisms to continue to live on the earth from one generation to the other.

Q12) Differentiate between sexual and asexual reproduction.

Ans: sexual production involves of two parents.

In asexual production mode of reproduction only a single parent is involved in producing new organisms.

Q13) How are oviparous animals different from viviparous animals?

Ans: oviparous animals lays eggs while viviparous animals give birth to young ones.

Q14) Discuss the importance of umbilical cord and placenta in human beings.

Ans: attached to the novel of the foetus is a flexible strand called the umbilical cord. The umbilical cord runs from the foetus and connects with the placenta. The placenta is attached to the wall of the uterus and is richly supplied with blood vessels. The umbilical cord connects the foetus with the circulatory system of the mother. This connection supplies the foetus with oxygen and nutrients from the mother. It takes away carbon dioxide and the other waste products from the foetal  blood  into the mother’s circulatory system.

Q15) What is menstruation cycle.

Ans: When the egg is released from the ovary, the inner of the uterus begins to thicken. If the egg gets fertilized it attaches to the wall of the uterus and receives nourishment. If the egg is not fertilized, the lining of ururus is shed and there is a loss of blood. This is known as menstruation or periods.

Once the wall is shed, it begins to build again. This continuous building and shedding of the inner wall of the uterus occurs during a menstrual cycle.

Q16) Differentiate between external and internal fertilisation.

Ans: in many animal such as fish and frogs, fertilisation takes place outside the body. The female animal releases eggs in the water. At the same time, the male releases sperms in the water and on reaching an egg, one of them penetrates the egg and fertilises it. The fertilised egg remains in the water and develop into a new individual.

Internal fertilisation in all kinds of land dwelling animals such as insects, reptiles, snake, lizards, tortoises and crocodiles, birds and mammals, fertilisation does not occur in the external environment. This is because the land offers dry condition whereas the egg and sperm cell require a watery medium to survive. In all these animals the egg cell is fertilised by the sperm cell inside the femal’s reproduction system. This type of fertilisation is called internal fertilisation.

Q17) List the difference between a zygote and a foetus.

Ans:

Zygote	foetus
The fusion of the nucleus of the sperm with the nucleus of the egg results in the formation of zygote	The embryo which resemble a human being is known as foetus
The zygote begins to divide and move towards the uterus.	It takes 36-40 weeks or nine months for a human child to fully develop in the mother’s womb.

Q18) describe asexual reproduction in hydra with a diagram.

Ans: Animals like hydra, sponge and sea anemone reproduce asexually by growing buds. The buds separate from the parent and grow as individuals

  

Q19) describe the life cycle of a butterfly

Ans:

Q20) How does the foetus get nourishment

Ans: the placenta is attached to the wall of the uterus and is richly supplied with blood vessels. The umbilical cord connects the foetus with the circulatory system of the mother. This connection supplies the foetus with oxygen and nutrients from the mother. It takes away carbon dioxide and the other waste products from the foetal blood into the mother’s circulatory system.

Q21) Explain the development of the human ebryo

Ans: the developing zygote is now called the embryo. As the human embryo develops it gets enclosed in a thin membrane called amnion. The amnion forms a kind of bag around the embryo and is filled with a watery fluid called the amniotic fluid. After a few weeks the embryo begins to resemble a human beings and is called a foetus. It takes about 36-40 weeks or nine months for a human child to fully develop in mother’s womb. This period is known as ( pregnancy )