Answer:
a. heart development.
Explanation:
As the third week of fetal development starts, the process of formation of blood vessels begins. Also, the splanchnic mesoderm in the head end of the embryo forms heart on days 18 and 19. Since it develops heart, this part of the mesodermal cells is called the cardiogenic area. The underlying endoderm sends the induction signals to these mesodermal cells to form a pair of endocardial tubes that gradually develop into a single primitive heart tube.
This primitive heart begins to beat by the end of the third week of development. Therefore, any drug that affects fetal development during the first 20 days of the pregnancy might affect the development of the heart.
Answer:
20 large size leaves plants
40 medium sized leaves plants
20 small sized leaves.
Explanation:
PP = large leaves
P'P' = small leaves
PP' = medium leaves
PP' was crossed with another PP' plant:
PP' x PP'
progeny = PP, 2PP', and P'P'
PP = 1/4 x 80 = 20 large size leaves plants
PP' = 1/2 x 80 = 40 medium sized leaves plants
P'P' = 1/4 x 80 = 20 small sized leaves.
<em>Hence the phenotypes would be:</em>
<em>20 large size leaves plants</em>
<em>40 medium sized leaves plants</em>
<em>20 small sized leaves.</em>
Answer:
Carbon dioxide has also increased over the last 100 years-- from about 300 ppm to 370 ppm.
Explanation: