Q 1 – What is the other name for duct gland ?
Ans. Exocrine glands.
Q 2 – Name two duct glands.
Ans. Tear glands and sweat glands.
Q 3 – What are ductless glands ?
Ans. Ductless glands are those glands, from which the hormones are directly poured into the blood.
Q 4 – Name any two ductless glands.
Ans. Pituitary gland and thyroid gland.
Q 5 – Define hormones
Ans. Hormones are secretions from endocrine glands.
Q 6 – Name a gland whose size gets reduced as the child grows older.
Ans. Thymus gland.
Q 7 – Name the hormone secreted by
- adrenal gland
- pancreas.
Ans.
- Adrenalin
- Insulin.
Q 8 – Which gland secretes the hormone thyroxine ?
Ans. Thyroid gland.
Q 9 – Which gland is known as the master gland ?
Ans. Pituitary gland.
Q 10 – Name the female sex hormone and where is it produced ?
Ans. Estrogen is produced in the ovary.
Q 11 – Name the male sex hormone and where is it produced ?
Ans. Testosterone is produced in the testes.
Q 12 – What is the main function of the sex hormones ?
Ans. The main function of sex hormones is to control sexual characteristics.
Q 13 – Name the sex glands in male and female.
Ans. The sex glands are testes in male and ovaries in female.
Q 14 – Apart from estrogen, name the other female hormone secreted by ovaries.
Ans. Progesterone
Q 15 – Which gland is responsible for the fatness in the body ?
Ans. Thyroid gland
Q 16 – Which hormone causes sweating under fear ?
Ans. Adrenalin
Q 17 – What do you understand by puberty ?
Ans. The age at which girls and boys attain reproductive maturity is known as puberty.
Q 18 – Which is the age of adolescence ?
Ans. The period of development from childhood to womanhood or manhood is the period of adolescence.
Q 19 – Which is the prescribed marriageable age for boys and girls ?
Ans. Marriageable age for girls is 18 years and for boys is 21 years.
Q 20 – Do all the eggs carry similar set of chromosomes ?
Ans. Yes, all eggs carry X – chromosomes
Q 21 – Why should adolescents eat a balanced diet ?
Ans. A balanced diet during adolescence helps in proper development of reproductive organs and a beautiful body.
Q 22 – Which is the main change in boys at puberty ?
Ans. The most obvious change in body is the sudden increase in height. The person looks tall because the bones of the legs and arms suddenly become long
Q 23 – What is the difference in the reproductive activity of male and female humans ?
Ans. In male humans the reproductive activity is from puberty to 60 or 70 years.
In female humans the reproductive activity is from puberty to 45 to 50 years.
Q 24 – A mother is angry at her child for misbehaving. The child is also afraid of scolding. Which hormones would be released in both their bodies ? What will be the effect of the hormone ?
Ans. When the mother is angry and the child is afraid more adrenalin would be released from the adrenal gland. Due to this there will be heavy sweating and lowering of body temperature.
Q 25 – Give one similarity and one difference in the secondary sex characters developed in boys and girl.
Ans.
- Similarity : In both boys and girls hair start to grow in arm pits and the pubic region above the thighs.
- Difference : In boys, moustaches and beard appear due to growth of facial hair.
- In girls, the breast develop and menstrual cycle starts.
Q 26 – What circumstances led to female foeticide being illegal ?
Ans. In our country female foeticide is illegal because the female population is decreasing. In Indian society, girls are considered a burden. Lot of expenditure is incurred as dowry on girls marriage. Also due to ill treatment by family members, many social groups kill their daughters.
Q 27 – One of the paternal twins may be a girl and the other may be a boy. Why ?
Ans. Paternal twins are not of the same sex. They are a result of double fertilisation — fertilisation of two ova from two sperms
Q 28 – Show diagrammatically how the sex of the child is determined ?
Ans.
Q 29 – What is menstruation ? Explain.
Ans. Before a zygote is received in the uterus, the uterus wall becomes thick with a lining of soft and spongy tissue full of blood vessels. In case fertilisation does not take place, the ovum along with the lining and blood vessels along the uterus wall shed off. This results in bleeding in women which continues for 2 to 3 days. This is called menstruation.
Q 30 – Calculate the full height of Esha 8 years old and 110 cm tall at the end of the growth period. (% of full height at this age = 77%).
Ans. Full height in cm = (Present height (cm)*100) / % of full height at this age
Full height in cm = (110*100) / 77
Full height = = 142 6/2 cm.
Q 31 – How should the adolescents take care of their health ?
Ans. During adolescence one should take care of personal health and hygiene.
- Physical exercise should be taken.
- Personal hygiene should be maintained by taking bath daily.
- Proper nutrition should be taken by eating balanced diet.
- Drugs and smoking should be avoided.
- Sexual contact of any kind should be avoided.
Q 32 – Explain how menstruation takes place.
Ans. Before a zygote is received in the uterus, the uterus wall becomes thick with a lining of soft and spongy tissue full of blood vessels. This is to receive the zygote. If the fertilisation does not take place, the ovum along with lining and the blood vessels along the uterus wall shed off. This results in bleeding in women which continues for 2 or 3 days. This is known as menstruation.
Q 33 – Name the six endocrine glands. Where is each gland located ?
Ans. Name of gland Position in the body
- Pituitary gland beneath the brain.
- Thyroid gland on the windpipe.
- Parathyroid gland on the larynx.
- Adrenal gland one on each kidney.
- Pancreas near the intestines.
- Sex gland testes in males and ovaries in females
Q 34 – Why is population control important ?
Ans. Controlling the growth of population is important because it is difficult to provide food, shelter and other necessities of life for a large population. If the population is high the poverty cannot be removed from the country. To improve the economic standard of a country it is important to control the population.
Q 35 – How can the population be controlled ?
Ans. Population can be controlled by controlling the number of pregnancies. Many methods have been developed to avoid the sperm cells from meeting the ovum. A large number of family welfare centres have been set-up to educate the people on family planning. They also educate the people on various methods of birth control and safe sex.
Q 36 – What are the reasons for increase in population ?
Ans.
- Ignorance — many people do not know the various methods available.
- Traditional beliefs — many people think children are the gift of God.
- Economic reasons — poor people think children are helping hands to increase the income of the family.
- Mortality rate — the number of children dying among poor people is more, so they tend to have more children.
Q 37 – List changes in the body that take place at puberty.
Ans.
- Increased height.
- Better development of muscles.
- Change in body shape.
- Change in voice.
- More sweating from sweat glands.
- More secretions from oil glands.
- Development of secondary sex characters.
- Attainment of mental, intellectual and emotional stability.
Q 38 – Write notes on :
- Adam’s apple
- Secondary sexual characters
- Sex determination in the unborn baby
Ans.
- In boys the voice changes due to better growth of larynx, which protrudes on the throat forming Adam’s apple. Thus, the voice becomes deep and hoarse.
- Secondary sex characters develop-
- In both, boys and girls, hair starts growing in arm pits and the pubic region.
- In boys moustache and beard appear. In girls, oestrogen makes the breasts develop with milk secreting glands inside.
- The sex of the baby is determined by the XX and XY chromosomes in a zygote. X chromosome stands for female and Y chromosome for male character. When X and X chromosomes form zygote (XX) the baby is female. When X and Y chromosomes form zygote (XY) the baby is male
Q 39 – Say ‘No’ to drugs”. Comment.
Ans. During adolescence children may feel insecure at times. Then they may feel like taking drugs. They should not take them’until prescribed by a doctor. The child can be addicted to drugs which may harm his health – both physical and sexual.
Q 40 – Give some ways in which AIDS can be transmitted.
Ans. AIDS can be transmitted by-
- Sexual contact with another HIV infected person.
- Using syringes already used by infected person.
- Through the milk of the infected mother to the infant.