Biology Test Biology Developmental Biology & Embryology 2

Question 1

What is embryonic induction?

Accepted Answer

The ability of one group of cells to signal adjacent cells to adopt a specific developmental fate

Answer

The formation of genetically identical twins

Answer

The process of fertilization between egg and sperm

Answer

The process of DNA replication in early cleavage stages

Question 2

Hox genes are critical to animal development primarily because they:

Accepted Answer

Determine positional identity along the anterior-posterior body axis by encoding transcription factors

Answer

Code for all major structural proteins in the cytoskeleton

Answer

Control the rate of mitotic cell division exclusively

Answer

Produce circulating growth hormones that regulate organ size

Question 3

What is the role of apoptosis in normal embryonic development?

Accepted Answer

It sculpts structures by removing specific cells, such as the interdigital webbing between developing fingers

Answer

It triggers oncogenic transformation in rapidly dividing cells

Answer

It is a purely destructive process with no constructive developmental role

Answer

It accelerates mitosis by clearing senescent cells from the cell cycle

Question 4

What are neural crest cells and why are they significant?

Accepted Answer

A highly migratory population derived from the dorsal neural tube that gives rise to diverse cell types including peripheral neurons, melanocytes, and craniofacial cartilage

Answer

Cells that line the inner surface of the neural tube and produce cerebrospinal fluid

Answer

Specialized cells permanently residing in the spinal cord that relay sensory signals

Answer

Cells in the lens of the eye derived from head ectoderm

Question 5

Which term describes the process by which embryonic cells become increasingly structurally and functionally specialized during development?

Accepted Answer

Differentiation

Answer

Proliferation

Answer

Migration

Answer

Determination

Question 6

What is a morphogen gradient?

Accepted Answer

A concentration gradient of a signaling molecule that provides cells with positional information to guide their developmental fate

Answer

A gradient of available nutrients across different regions of the blastocyst

Answer

The gradient of cardiac output established in the developing heart

Answer

A pH gradient maintained across the plasma membrane of embryonic cells

Question 7

What is organogenesis?

Accepted Answer

The process by which the three primary germ layers differentiate into the specific organs and organ systems of the body

Answer

The scientific study of organ transplantation and rejection

Answer

The process of gamete formation from gonadal stem cells

Answer

The regenerative repair of damaged organs in adult organisms