Answer:
From fertilization and to the end of the second week.
Explanation:
The development of the fetus is divided into three periods, established by most embryologists: pre-embyonic period, which goes from fertilization to the second week of development, embryonic period, which goes from the third week to the eighth week, and the fetal period, which goes from from the third month until the end of pregnancy.
The pre-embyonic stage begins at fertilization and remains until gastrulation. By the end of the second week the embryo already has the neural tube formed, although it is still open at both ends.
Neurogenesis has been found seen in the <span> hippocampus and in the olfactory </span>
The correct answer is that the <span>Turtles have a partial septum in their ventricle.
A septum is responsible for separating the two ventricles in a turtle's hurt, same goes for the humans. Wherein it divides two parts of the heart, the left and right ventricle in the heart.</span>
Answer is D. Because the chemoreceptors located in the carotid and aortic bodies monitor the concentration of carbon dioxide and oxygen in the arterial blood.
