Question 20 - Past Year - 3 Mark Questions - Chapter 8 Class 10 - How do Organisms Reproduce?

State the changes that take place in the uterus when:

(i) Implantation of embryo has occurred.

(ii) Female gamete/egg is not fertilised.

Answer:

(i)

After implantation, 

• a disc-like special tissue develops between the uterus wall and the embryo called the placenta.  
• It is through the placenta that all the requirements of the developing foetus like nutrition, respiration, excretion, etc are met from the mother’s body. 

(ii)  

If the female gamete is not fertilised, 

• then the thick and spongy uterus lining is not required. 
• So, this breaks down and comes through the vagina as blood and mucus ie., menstruation occurs.