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CBSE Sample Paper Class 8 Science Reaching The Age of Adolescence
1.) Answer the short questions (15×1)
a.) What is adolescence?
b.) What is the most important change happens in puberty?
c.) What are secondary sexual characters?
d.) What controls the changes in adolescence?
e.) What is hormone?
f.) Which hormone controls the changes in girls during puberty?
g.) What is menarche?
h.) What is menopause?
i.) What are sex chromosomes?
j.) Where is pituitary gland is attached?
k.) Name the sex hormones.
l.) Name the endocrine glands of the body.
m.) Which hormone is produced by thyroid gland?
n.) What is the function of adrenaline?
o.) What is metamorphosis?
2.) Briefly answer the following questions (5×1)
a.) What are the changes occur during puberty?
b.) Describe the increase in height in puberty.
c.) Effect on voice during puberty.
d.) Describe how hormone controls the onset of puberty.
e.) What is menstruation?
3.) Fill in the blanks (10×1)
a.) Changes in adolescence are controlled by _______.
b.) Hormones are secreted form ________ glands.
c.) ________ is released by the testes.
d.) Hormones reach to a particular body part called ________ .
e.) Beginning of menstruation is called ________ .
f.) ________ is the term used for stoppage of menstruation.
g.) Female has _______ chromosomes.
h.) _______ is responsible for the sex of an unborn baby.
i.) Goitre is a disease of _______ gland.
j.) Pancreas produces _______ hormone.
4.) Write true or false (10×1)
a.) Pituitary gland is attached in stomach.
b.) Mother determines the sex of an unborn baby.
c.) Growing up is a natural process.
d.) Girls have two X chromosome.
e.) Hormones acts on target site.
f.) Adrenal is secreted by thyroid gland.
g.) Hormones are released by exocrine gland.
h.) Testosterone is secreted in boys.
i.) Diabetes is associated with insulin hormone.
j.) Growth hormone is released by pituitary gland.
Answer
1.) Answer the short questions (15×1)
a.) What is adolescence?
Answer –Adolescence is a period of life in which a person’s body undergoes significant changes leading to reproductive maturity.
b.) What is the most important change happens in puberty?
Answer –The most important change happens in puberty is the reproductive capability.
c.) What are secondary sexual characters?
Answer –Secondary sexual characters are the characteristics which differentiate boys and girls, such as development of breast in girls and beard and moustache in boys.
d.) What controls the changes in adolescence?
Answer –The changes in adolescence are controlled by hormones.
e.) What is hormone?
Answer –Hormones are chemical substances which are secreted by the endocrine glands of our body and which controls the changes in our body during adolescence.
f.) Which hormone controls the changes in girls during puberty?
Answer –Progesterone hormone controls the changes in girls during puberty.
g.) What is menarche?
Answer –The menstrual flow in girls is termed as menarche.
h.) What is menopause?
Answer –The stoppage of menstruation at the age around 45-50 years old is termed as menopause.
i.) What are sex chromosomes?
Answer – There are two sex chromosomes XX and XY. Girls have XX and boys have XY chromosomes.
j.) Where is pituitary gland is attached?
Answer –Pituitary gland is attached to the brain.
k.) Name the sex hormones.
Answer – The sex hormones are testosterone and estrogen.
l.) Name the endocrine glands of the body.
Answer – The endocrine glands of the body are thyroid gland, adrenal gland, pituitary gland, pancreas etc.
m.) Which hormone is produced by thyroid gland?
Answer –Thyroid gland produces thyroxine hormone.
n.) What is the function of adrenaline?
Answer –Adrenaline helps our body to adjust to stress while we are angry, embarrassed or worried.
o.) What is metamorphosis?
Answer –Metamorphosis is a process by which larva converts into adult.
2.) Briefly answer the following questions (5×1)
a.) What are the changes occur during puberty?
Answer –The changes occur during puberty are,
- Increase in height
- Changes in body shape
- Voice change
- Development of sex organs
- Reaching mental, emotional and intellectual maturity.
b.) Describe the increase in height in puberty.
Answer –In puberty there is increase in height. During puberty the bones of arms and legs elongate making the person tall. It is one of the most significant changes that can be observed in puberty. The growth in height can be different in different individuals. Growth can be sudden or steady.
c.) Effect on voice during puberty.
Answer –There is a significant change occurs during puberty. The voice box or larynx starts to grow during puberty. The voice box is bigger in boys than girls. The voice box grows and you can see it as a protruding part of the throat. This is called Adam’s apple. In girls larynx is hardly seen as it is smaller in size.
This different growth of the voice box results in different types of sound. Boys have deep voice while girls have high pitched voice.
d.) Describe how hormone controls the onset of puberty.
Answer –hormones are chemical substance that are secreted from endocrine glands of our body. Hormones control the onset of puberty by the following process,
- At first hormones of pituitary gland stimulates endocrine glands such as testis and ovary.
- Stimulated testis and ovary produces testosterone and estrogen.
- Then these hormones are released to the bloodstream and carried to the target site.
- After reaching the target site hormones cause different changes in our body at the onset of puberty.
e.) What is menstruation?
Answer –menstruation is a normal biological process which happens in the female body. In this process the unfertilized eggs, thickened lining of uterus along with its blood vessels are shed off. This causes breeding in women.
Menstruation cycle occurs in about 28 to 30 days. Menstruation cycle starts at puberty, it is termed as menarche and ends at the age of 45 to 50 years old, it is termed as menopause.
3.) Fill in the blanks (10×1)
a.) Changes in adolescence are controlled by hormones.
b.) Hormones are secreted form endocrine
c.) Testosterone is released by the testes.
d.) Hormones reach to a particular body part called target site .
e,) Beginning of menstruation is called menarche .
f.) Menopause is the term used for stoppage of menstruation.
g.) Female has XX
h.) Father is responsible for the sex of an unborn baby.
i.) Goitre is a disease of thyroid
j.) Pancreas produces Insulin
4.) Write true or false (10×1)
a.) Pituitary gland is attached in stomach.
Answer – False
b.) Mother determines the sex of an unborn baby.
Answer – False
c.) Growing up is a natural process.
Answer – True
d.) Girls have two X chromosome.
Answer –True
e.) Hormones acts on target site.
Answer – True
f.) Adrenal is secreted by thyroid gland.
Answer – False
g.) Hormones are released by exocrine gland.
Answer –False
h.) Testosterone is secreted in boys.
Answer – True
i.) Diabetes is associated with insulin hormone.
Answer – True
j.) Growth hormone is released by pituitary gland.
Answer – True