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.
Answer:
i think it is good because it helps treat depression which will help those who suffer from depression
Explanation:
1) I would choose white blood cells since their main job is to fight infection (Something that does not belong as a part of the body) But since their is several types of white blood cells the ones too look out for would be the <span>Neutrophils since they kill bacteria by ingesting them.
2) It would be a Neutrophils blood cell. They </span><span>are 12-14 µm diameter, and so </span>look<span> bigger than the surrounding red </span>blood cells<span>. There is a single nucleus, which is multilobed, and </span>can<span> have between 2 and 5 lobes.
3)You would also have to watch out for: </span><span><span>Granulocytes – cells which contain granules which contain chemicals that are used to kill bacteria and viruses </span><span>Lymphocytes- cells which attack most of the bacterial and viral infections in our bodies</span><span>Monocytes - cells which become macrophages, large cells that engulf harmful particles in our bodies</span></span>
Having friends that are sexually active and prior sexual activity and dating older people