Q14 of 38 Page 1

“Different species use different strategies to determine the sex of a newborn individual. It can be environmental cues or genetically determined”. Justify this statement giving reason/example.

In some animals temperature in which fertilized egg is incubated plays an important role in determining the sex of the new born. Example – turtles, lizards.

Genetically in human sex is determined. X bearing sperm when fertilizing the egg it will be a girl and Y bearing sperm when fertilizing an egg it will be a boy.


More from this chapter

All 38 →
12

List any four methods of contraception used by humans. How does the use of three methods have a direct effect on the health and prosperity of a family?

 13

List two functions each of the following points of the human female reproductive system

(a) Ovaries


(b) Fallopian tubes


(c) Uterus

 15

List in tabular form, two distinguishing features between the acquired traits and the inherited traits with one example of each.

 16

A student has to project a three times magnified image of a candle flame on a wall. Name the type of the lens (converging/ diverging) required for the purpose. If the candle flame is at a distance of 6 m from the wall, find the focal length of the lens.