In which of the following ways is the general development of a fetus different during the first and third trimesters?

The pregnancy is divided into three trimesters and each trimester has its own characteristics. A trimester is a period of 3 months in which development of different parts of baby takes paces.

These are the changes appear during first trimester:

-The baby develops all its organs by the end of third month  

-The heart starts functioning and the formation of bones begin

In third trimester, baby goes through following stages:

-External genitalia starts forming

-The fetus starts moving inside the amniotic fluid  

-Tooth buds are fully developed  

-At this stage, the heart is developed and functioning  properly

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

c is the correct answer hope this !