Biology Test Biology Developmental Biology & Embryology

Question 1

What term describes the series of rapid mitotic cell divisions that occur immediately after fertilization, producing smaller and smaller cells?

Accepted Answer

Cleavage

Answer

Cleavage refers to the rapid mitotic divisions following fertilization that divide the zygote into blastomeres without significant cell growth between divisions.

Question 2

What is the inner cell mass (embryoblast) of the blastocyst primarily responsible for forming?

Accepted Answer

The embryo proper and some extraembryonic structures

Answer

The inner cell mass of the blastocyst gives rise to the embryo proper as well as some extraembryonic membranes, and is the source of embryonic stem cells.

Question 3

During gastrulation, which three primary germ layers are established?

Accepted Answer

Ectoderm, mesoderm, and endoderm

Answer

Gastrulation establishes the three primary germ layers—ectoderm, mesoderm, and endoderm—from which all tissues and organs of the body will ultimately develop.

Question 4

Which germ layer gives rise to the central nervous system, including the brain and spinal cord?

Accepted Answer

Ectoderm

Answer

The ectoderm, specifically the neuroectoderm, gives rise to the central nervous system through the process of neurulation.

Question 5

What is neurulation?

Accepted Answer

The process by which the neural plate folds and fuses to form the neural tube

Answer

Neurulation is the embryonic process by which the flat neural plate (derived from ectoderm) folds at the neural folds and fuses to create the hollow neural tube, precursor to the brain and spinal cord.

Biology Practice Test

Biology Practice Test

Biology Test Biology Developmental Biology & Embryology