CLEP CLEP Biology Animal Behavior and Reproduction 3

Question 1

Gastrulation during animal embryonic development produces:

Accepted Answer

The three primary germ layers: ectoderm, mesoderm, and endoderm

Answer

A hollow single-layered blastula

Answer

The fertilized diploid zygote

Answer

The chorion and amnion of the placenta

Question 2

Neural crest cells, which migrate away from the developing neural tube, give rise to which structures?

Accepted Answer

Peripheral nervous system, facial bones, and adrenal medulla

Answer

Brain and spinal cord neurons exclusively

Answer

Cardiac muscle and major blood vessels

Answer

Liver, pancreas, and digestive epithelium

Question 3

Embryonic induction refers to which developmental process?

Accepted Answer

One tissue group signaling to alter the developmental fate of adjacent cells

Answer

Cleavage divisions that produce the blastomeres

Answer

Formation of the neural plate from dorsal ectoderm

Answer

Programmed cell death to sculpt organ shapes

Question 4

Complete metamorphosis (holometabolism) in insects follows which sequence of developmental stages?

Accepted Answer

Egg → larva → pupa → adult

Answer

Egg → nymph → adult

Answer

Egg → juvenile → subadult → adult

Answer

Egg → larva → adult

Question 5

Apoptosis during embryonic development is functionally important because it:

Accepted Answer

Eliminates unneeded or harmful cells to sculpt tissues and organs

Answer

Increases total cell number for forming complex organs

Answer

Promotes rapid cell division in developmental growth zones

Answer

Supplies nutrients to rapidly proliferating neighboring cells

Question 6

The anterior-posterior body axis in Drosophila embryos is primarily established by:

Accepted Answer

Maternal effect genes like bicoid and nanos that form protein concentration gradients

Answer

Hox genes expressed uniformly throughout the embryo

Answer

Random distribution of transcription factors at fertilization

Answer

Zygotic segmentation genes activated before fertilization occurs