Answer:
Excretion
Explanation:
The excretory system removes cellular wastes and helps maintain the salt-water balance in an organism. When cells break down proteins, they produce nitrogenous wastes, like urea. The excretory system serves to remove these nitrogenous waste products, as well as excess salts and water, from the body.
<span>Reactive or evocative correlation. An example would be a child that shows particular interest and talent to sports. The parents are not particularly inclined to sports and grew up not playing them, but provides the child with opportunities to play and practice them. This action by the parents reinforces the child's genetic tendency to sports.</span>
1/4 recessive can be expected for the recessive trait of mono hybrids from the F2 generation.
Option D
<h3><u>
Explanation:</u></h3>
Mono hybrid cross is defined as the crossing between two plants considering the two different alleles of a particular character. It was 1st performed by Father of Genetics, Sir Gregor Mendel. The mono hybrid cross done by him considered the character tallness of garden pea plants, of which one was tall and other was short.
He crossed them to get all tall plants in 
Filial generation. Now as he self bred those plants, he got the tall and short plants in ratio of 3:1. Thus he proved that the recessive trait of mono hybrids is 
of the total population of F2 generation.
