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

The fluid that contains sperm is testosterone.
A. True
B. False

Question 2

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 3

The table lists some of the body parts present or absent in an unknown organ system.?PartYes or NoMouthYESStomachNOLungsYESTracheaYESKidneyNONostrilYESWhich organ system does the table represent?
A. nervous
B. digestive
C. circulatory
D. respiratory

Question 4

The heart contracts on its own about 200,000 times a day.
A. True
B. False

Question 5

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