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.
Life style, environment toxins, and Gene mutations
Answer: direct services
Explanation: The missing component here is one of the main purposes for having human service intervention at all in a community. Direct services are often what the administrators are overseeing and planning programs to carry out. This is in an effort to meet human needs in a service population area, prevent and resolve problems, and just to keep up and even increase people's quality of life.
