In human males, one pair called as the sex chromosomes are unpaired. Here, one is a normal sized X chromosome while other is a short Y chromosome. Women have a perfect pair of sex chromosomes, both called as X
Acquired traits develop in response to the environment. The size of the body is an acquired trait because it can be changed on the availability of less or more food. The other three- colour of eye and skin and nature of hair are inherited characters from the parents.