development and inheritance 1

Germ-layer formation results from the process of __________.

gastrulation

The term for what occurs when the blastocyst touches and grows into the endometrium is __________.

implantation

What is the fate of the cluster of cells in the blastocyst known as the inner cell mass?

the cells will develop into the embryo

Exchange between the embryonic and the maternal circulations occurs by diffusion across the syncytial and cellular trophoblast layers via __________.

the chorionic blood vessels

The Extra-embryonic membranes that develop from the endoderm and the mesoderm are the __________.

yolk sac and the amnion

What triggers the activation of the secondary oocyte?

Fusion of the sperm and secondary oocyte membranes

What happens in the process of hatching?

The zona pellucida is shed from the blastocyst.

Which of the following is NOT one of the germ layers formed during gastrulation?

Trophoderm

What is the extra-embryonic membrane that gives rise to the urinary bladder?

allantois

Which of the following is the term for the events that occur during the first two months of development after fertilization?

embryological development

What event marks the onset of development?

fertilization

Which of the following is the term for the developmental events events that occur between the ninth week and birth?

fetal development

What is the "moment of conception"?

fusion of the male and female pronuclei

The umbilical cord, or umbilical stalk, contains __________.

the allantois, blood vessels, and yolk stalk

What is the meaning of the term gestation?

All of prenatal development

Which of the following does NOT happen during oocyte activation?

The first cleavage is completed.

Gastrulation produces three germ layers. Which of the following is not one of those layers?

blastocoele

A hollow ball of cells created by cleavage is called a __________.

blastocyst

Which of the following forms the placenta?

chorion

A sequence of cell divisions that begin after fertilization is called __________.

cleavage

Throughout embryonic and fetal development, metabolic wastes generated by the fetus are eliminated by their transfer to the __________.

maternal circulation

The chorion develops from the __________.

mesoderm and the trophoblast

Fertilization usually occurs in the __________.

uterine tube

The fusion of male and female pronuclei is termed __________.

amphimixis