Basic Science Solutions for Class 8 Science Chapter 4 Reproduction are provided here with simple step-by-step explanations. These solutions for Reproduction are extremely popular among Class 8 students for Science Reproduction Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Basic Science Book of Class 8 Science Chapter 4 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Basic Science Solutions. All Basic Science Solutions for class Class 8 Science are prepared by experts and are 100% accurate.

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Asexual reproduction is a type of reproduction in which only one parent is required. An individual produces offspring(s) without the help another individual.

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The male gamete is known as sperm and female gamete is known as ovum in human beings.

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In frogs, reproduction takes place outside the body.

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The male reproductive system consists of testes, vas deferens, epidydymis and penis.

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Fertilisation takes place in the fallopian tube of female human beings.

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Embryo receives nutrition in the mother's womb through the placenta, which is attached to the embryo by the umbilical cord.

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The female reproductive system of human beings consists of ovaries, fallopian tube, uterus and vagina.

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The zygote formed after fertilisation of the ovum divides to form the embryo, which gets attached to the wall of the uterus.

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Secondary sexual characters in males are regulated by testosterone (male sex hormone).

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Menstrual cycle refers to a 28-day cycle that occurs in female human-beings. It involves the process of ovulation, thickening of the uterine wall and menstruation. If the ovum remains unfertilised, it is removed through the vagina along with the lining of the uterus and blood that flows out of the body through the vagina by the process of menstruation in the form of menstrual flow.

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Twins are born when two ova are matured and released at the same time. These ova get fertilised by two sperms and results in the birth of twins, which are non-identical. Sometimes the fertilised egg divides into two, leading to the birth of identical twins.

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Endocrine glands are those glands that produce and then release hormones into the blood. They control and coordinate the functioning of many organs of the body. Hormones act like chemical messengers that are carried by the blood to specific tissues. They tell the tissues or organs how to function.

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A taboo is a social or religious custom that prohibits or restricts a particular behaviour or practice.
Example: Widow remarriage was considered a taboo in India before the passage of Widow Remarriage Act in 1856.

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Secondary sexual characters are those physical changes that occur at puberty in males and females and distinguish males and females physically.

Secondary sexual characters in males are:
(a) Growth of hair on the face, pubic region and armpits
(b) Deepening of the voice
(c) Broadening of shoulders and chest
(d) Development of muscles

Secondary sexual characters in females are:
(a) Enlargement of the breasts
(b) Growth of hair in pubic region and armpits
(c) Widening of the pelvic girdle
(d) Elongation of hair

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Gender roles refer to those functions that society sees as feminine and masculine. There is no law that tells a girl and a boy to perform a particular function or to behave in a particular manner. However, the society has certain restrictions on what girls and boys should do. Generally, females are associated with nurturing, caring and looking after her family, whereas males are associated with protection, valour, physical stamina and ability to perform physical works.

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The sex of the foetus is determined by the chromosomes in its cells. The cells of the foetus are obtained by withdrawing amniotic fluid through a special needle from the mother's womb. Ultrasonography is another method of sex determination in which a sound picture of the mother's abdomen is taken.
Sex determination is prohibited by law because many people, who do not want girls, go for sex determination test of the foetus and may kill it if it is a female. This is called foeticide.



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1. The placenta is attached to the embryo by the umbilical cord.
2. Non-identical twins are also called fraternal twins.
3. The hormone that regulates the secondary sexual characters in females is called oestrogen.
4. The pituitary gland regulates growth and controls the functioning of the other endocrine glands.
5. The adrenal glands are attached to the kidney.
6. The mixture of secretions and sperms transferred into the vagina by the penis is called semen.

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(a) testes

Sperms are produced by the testes.

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(c) amniotic sac

Embryo is protected inside the uterus by the amniotic sac.

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(b) pancreas

Pancreas controls the level of glucose in the blood.

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(c) rate at which energy is produced

Thyroid gland controls the rate at which the energy is generated.

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(a) epididymis

Sperms get collected and matured in a tube called epididymis.

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(a)



 
(b)



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