What is the major function of the thyroid gland? The major function of the thyroid gland is to produce thyroid hormones, according to HowStuffWorks. One hormone is called thyroxine and the other triiodothyronine, or T4 and T3. Together, they regulate the growth and development of nearly every system in the body.
The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. Independent assortment helps account for the many genetic variations observed in plants,animals, and other organisms.
This process is known as anagenesis. More commonly, a species may become split into two groups that no longer share the same gene pool. This process is known as cladogenesis. There are several ways in which anagenesis and cladogenesis may take place. In all cases, reproductive isolation occurs.