Explanation:
The embryonic stage is the third to the eighth week after fertilization. that should be the ansewr
Answer:
D. Transport of oxygen through a placenta to a fetus.
Explanation:
Zygotes are fertilized egg cell, zygotes aren't produced in the ovaries but ovums or egg cells are produced in the ovaries. So option A is false.
Fertilization is internal not external in human. Option B is wrong.
Production of milk happens in the mammary gland (the breast) not in the reproductive system. Option C is false.
Transport of oxygen through a placenta to a fetus. The placenta is a vascular organ which is implanted in the wall of the uterus (a part of the female reproductive system) and links to the foetus through the umbilical cord.
The vegetation of the tundra is composed of shrubs, grasses, mosses, lichens. Tree vegetation is very rare because of low temperature and short growing season.
Answer:
It is a beneficial mutation.
Explanation: Mutations are permanent changes in the nucleotide sequence of a DNA. Mutations can beneficial, neutral and harmful or deleterious. When change in the nucleotide sequence of DNA a mutation enhances the effectiveness of a protein or improves the protein function, it is said to be beneficial. When a mutation causes the synthesis of a protein which have the same amino acid as the original protein and performs the same function as the original protein, it is said to be silent or neutral. When a mutation results in the synthesis of a protein with an altered amino acid sequence and a nonfunctional protein, it is said to be harmful.
