Q: What is differentiation in embryonic development

A: Differentiation is the process by which unspecialized cells become specialized cells that form tissues and organs with distinct functions.

Q: What is morphogenesis

A: Morphogenesis is the development of an animal's shape or body form, involving the organization of cells into tissues and organs.

Q: What are the two functions of fertilization

A: 1. To combine two haploid sets of chromosomes into a diploid set. 2. To activate the egg, triggering developmental processes.

Q: What happens during cleavage

A: Cleavage is a rapid series of cell divisions that results in a solid ball of cells (morula), with no growth in the embryo size, only division of the original cell.

Q: What is a blastomere

A: A blastomere is a smaller cell formed during cleavage after the cytoplasm of the zygote is partitioned.

Q: What is the blastula stage

A: The blastula stage is when the embryo has formed a blastocoel (fluid-filled cavity) after cleavage and is fully hollowed out.

Q: What is gastrulation

A: Gastrulation is the process where cells from the outer surface of the embryo migrate inward, forming the blastopore and eventually creating three primary germ layers.

Q: What is the blastopore and its role in protostomes and deuterostomes

A: The blastopore is the opening where cells migrate inward. In protostomes, it forms the mouth, while in deuterostomes, it forms the anus.

Q: What are the three primary germ layers formed during gastrulation

A: The three primary germ layers are: ecto meso and endo

Ectoderm

– outer layer (nervous system, skin, etc.)

Mesoderm

– middle layer (muscles, skeleton, circulatory system, etc.)

Endoderm

– inner layer (digestive system, lungs, etc.)

Q: What does the ectoderm give rise to

A: The ectoderm gives rise to the nervous system, epidermis, associated glands of the skin (sweat and sebaceous), inner ear, lens of the eyes, and adrenal medulla.

Q: What does the mesoderm give rise to

A: The mesoderm gives rise to the notochord, muscles, skeleton, gonads, kidneys, circulatory system, dermis of the skin, and adrenal cortex.

Q: What does the endoderm give rise to

A: The endoderm forms the lining of the digestive tract, liver, pancreas, lungs, thyroid, parathyroid, and urinary bladder.

Q: What happens during neurulation

A: Neurulation involves the ectodermal cells flattening and sinking to form a neural groove. The edges elevate to form neural folds, which fuse to create a hollow neural tube.

Q: What is the neural tube

A: The neural tube is the structure formed after the neural folds fuse during neurulation. It gives rise to the brain and spinal cord.

Q: What is organogenesis

A: Organogenesis is the process by which organs begin to form, including the neural tube and notochord, which give rise to the brain, spinal cord, and vertebrae.

Q: What do somites form during organogenesis

A: Somites, formed from mesodermal blocks, give rise to the vertebrae of the backbone.