Learn Class 8 Science - Reproduction and Endocrine System

The reproduction and endocrine system chapter discusses all the stages of life. Like what happens when the body gets matured?

Meaning of Adolescence:

Adolescence is the period of life transition when the body suffers many changes, leading to reproductive maturity.

  • WHO defines the adolescence period.
  • And this period lies between 11-19 years old.
  • The human body suffers from many changes.
  • Such changes lead to the action of puberty.

What is puberty?

We can say that puberty is a phase:

  • When the reproductive organs work actively.
  • The stage gets ended when the adolescent attains maturity.

What are the changes during puberty?

Many changes happen at the time of puberty. LIKE:

  • Voice get change
  • Height get change
  • Emotional aspects
  • Mental development
  • Body shape get change

Hormones:

  1. Male hormones: Hormones in males are known as 'testosterone.'
  2. Female hormones: Hormones for females are known as 'estrogen.'

Zygote:

The zygote is formed with both sperm and fuse. Well, the sex chromosomes of sperm help in doing the determination of the kids' gender.

  • There are 23 chromosomes in a human cell.
  • Chromosomes pair form 'sex chromosomes.'
  • Male chromosomes: XY
  • Female chromosomes: XX

Learning Videos for 8th Grade Science - Reproduction and Endocrine System

Reproduction and Endocrine System Sample Questions for Class 8

Question 1

What are the reactants of cellular respiration?
A. water (H_2O) and glucose (C_6H_12O_6)
B. glucose (C_6H_12O_6) and carbon dioxide (CO_2)
C. carbon dioxide (CO_2) and water (H_2O)
D. glucose (C_6H_12O_6) and oxygen (O_2)

Question 2

What do red blood cells not do?
A. carry oxygen
B. fight germs
C. take carbon dioxide or waste away

Question 3

What large blood vessels take oxygenated blood from the heart to the body?
A. veins
B. capillaries
C. arteries

Question 4

Halogens are elements in Group .
A. 1
B. 15
C. 17
D. 18

Question 5

The skeleton in the human body serves the purpose of the
A. movement of the body.
B. transport of materials to the body.
C. support and protection of soft body parts.