Jason, a health teacher, explains to his class that for a to be created, the sperm of a male must unite with the egg from a female, a process that takes place during the prenatal period.

Zygote, germinal.

Explanation:

The process in which a sperm of a male fuses/unite with the egg/ovum of a female is known as fertilization which occurs in germinal prenatal period. As soon as sperm reaches female genital tract, it tends to move towards ovum which is present in fallopian tube. After formation of zygote, an embryo(2 cells) is formed by the first cleavage of zygote. After continuous cleavages the embryo is converted into morula (~ 16 - 64 cells)  and then into blastocyst  (~ 128 - 300 cells). The blastocyst then moves to the uterus where it can be implanted so that it could develop further. All this occurs during germinal prenatal period which starts from fertilization and ends with the formation of blastocyst.  

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )

the correct answer is d