Fertilization
Cleavage
Blastula
Gastrulation
Organogenesis
100

The union of sperm and egg is called…

What is fertilization?

100

The first few rapid cell divisions of the zygote are called…

What is cleavage?

100

The fluid-filled cavity inside a blastula is called…

What is the blastocoel?

100

The process that forms three primary germ layers is called…

What is gastrulation?

100

The process where germ layers develop into organs is called…

What is organogenesis?

200

The structure formed immediately after fertilization, a single-cell zygote.

What is a zygote?

200

These are the smaller cells produced by cleavage.

What are blastomeres?

200

The layer of cells that surrounds the blastocoel is called…

What is the blastoderm?

200

The three germ layers formed during gastrulation are…

What are ectoderm, mesoderm, and endoderm?

200

The nervous system originates from which germ layer?

What is the ectoderm?

300

The type of division the zygote undergoes without growth in size.

What is cleavage?

300

Cleavage that results in a hollow ball of cells is called…

What is blastulation?

300

In mammals, this structure that implants into the uterus is called…

What is a blastocyst?

300

The opening formed during gastrulation in the embryo is called…

What is the blastopore?

300

The heart and blood vessels develop from which germ layer?

What is the mesoderm?

400

This is the process where the egg and sperm membranes fuse, allowing the sperm nucleus to enter.

What is sperm-egg fusion?

400

Cleavage in mammals that results in cells of unequal size is called…

What is holoblastic, unequal cleavage?

400

The two main parts of a mammalian blastocyst are the inner cell mass and…

What is the trophoblast?

400

The ectoderm eventually forms structures like…

What are the skin and nervous system?

400

The digestive and respiratory lining come from which germ layer?

What is the endoderm?

500

The stage when the zygote’s chromosomes combine from both parents.

What is the diploid zygote stage?

500

The compacted mass of cells at the end of cleavage is called…

What is a morula?

500

The blastula stage is important for setting up…

What is the body plan or cell differentiation?

500

The mesoderm gives rise to…

What are muscles, bones, and the circulatory system?

500

The first organ to form in vertebrate embryos is usually…

What is the heart?