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.
They are called Consumers I believe hope that helps ☺
I think the correct answer would be the second option. The group of archaebacteria would be found on the lowest branch of a phylogenetic tree of all life. Phylogenic trees are illustrations of a hypothetical evolution of the organisms and its relationship with the other organisms. From the listed options, the archaebacteria is most likely to be the most basic and simplest life form. It should be placed before the other options so at the lowest branch. This illustration is being used by scientists to describe how evolution and the connection of the organisms came about. It sometimes called as the tree of life.
Answer:
They absorb the food molecules that result from the external digestion.
Explanation:
