19. Higher Order Thinking Skill (HOTS) I

1. In angiosperms the pollen germinates to produce pollen tube that carries two gametes. What is the purpose of carrying two gametes when single gamete can fertilize the egg?

 

a. One sperm cell unites with the egg cell to produce the  in angiosperms.

 

b. The other gamete fuses with the two  to form the , which feeds the developing embryo.

 

2. Why menstrual cycle does not take place before puberty and during pregnancy?

 

a. The reproduction period of a women’s life starts and becomes functional after puberty. This is because at puberty, there is an in sex hormone production. Thus, menstrual cycle does not take place before puberty.

 

b. The release of a  and the attachment of fertilized egg that secretes  maintains the lining of the uterus, during pregnancy.

 

c. During pregnancy, the  produces progesterone. This maintains the lining of the uterus during pregnancy, which cause the stoppage of menstruation.