Rubella has a disastrous impact if it is contracted during the first trimester of a pregnancy, yet has hardly any impact if contracted at the end of a pregnancy. this is an example of

This is an example of the critical period

Explanation:

Rubella or the German measles, is a highly contagious air-borne viral disease which is caused by the rubella virus, characterized by rash.

Rubella infection during the first trimester of pregnancy, can lead to miscarriage or a child born with the congenital rubella syndrome.

This is an example of the critical period. Critical period refers to the maturational stage of an organism during which the central nervous system is very sensitive to certain environmental stimuli.