Phases of Embryonic Development

Flashcards covering the 7 steps of embryonic development, including gametogenesis, fertilization, cleavage, blastulation, gastrulation, neurulation, and organogenesis.

Gametogenesis

Process by which diploid germ cells undergo changes to form mature haploid gametes.

Spermatogenesis

Male gametogenesis in testes producing sperms.

Oogenesis

Female gametogenesis in the ovary producing ova.

Animal Pole

The pole of the egg where yolk is least concentrated.

Animal Hemisphere

The hemisphere of the egg where the animal pole is located.

Vegetal Pole

The pole of the egg where yolk is most concentrated.

Vegetal Hemisphere

The hemisphere of the egg where the vegetal pole is located.

Fertilization

The process where two sex cells (gametes) fuse to create a new individual.

Cleavage

Repeated rapid mitotic cell divisions of the zygote to form the blastula.

Blastomeres

Cells produced during cleavage.

Morula

A ball of 32 cells formed by continued cleavage divisions.

Blastula

Hollow structure with up to several hundred cell formed by morula divisions

Blastocoel

Cavity of the blastula.

Blastulation

Production of a multicellular blastula.

Gastrulation

Morphogenetic process that rearranges cells of a blastula into a three-layered embryo (gastrula).

Gastrula

Three-layered embryo formed during gastrulation.

Endoderm

Inner embryonic germ layer.

Mesoderm

Middle embryonic germ layer.

Ectoderm

Outer embryonic germ layer.

Gastrocoel

New cavity formed during gastrulation.

Neurulation

Formation of a dorsal, hollow neural tube.

Neural Crest

Structure that guides the formation of several organ systems.

Organogenesis

Formation of the organs.

Endoderm (Organogenesis)

Innermost germ layer that forms the gut.

Mesoderm (Organogenesis)

Middle germ layer that forms muscles, circulatory system, blood, and many organs.

Ectoderm (Organogenesis)

Outermost germ layer that forms the skin and nervous system.

Somatic Cells

Cells found in all body tissues except gonads, containing diploid numbers of chromosomes.

Germ Cells

Cells found only in gonads (testes & ovary), containing haploid number of chromosomes.

Fertilization (Developmental Vocabulary)

Activate the egg & bring together the nuclei of the egg and sperm.

Cleavage (Developmental Vocabulary)

Partitions the zygote into many smaller cells.

Gastrulation (Developmental Vocabulary)

Rearranges the blastula to form a three-layered embryo with a primitive gut, the archenteron.

Organogenesis (Developmental Vocabulary)

Process by which the organs in the animal body form from the three embryonic germ layers.

Blastula (Developmental Vocabulary)

Hollow sphere of cells (128 cells) formed by cleavage of the morula.

Gastrulation (Developmental Vocabulary)

Process leading to the creation of the primitive gut or archenteron.

Gastrula (Developmental Vocabulary)

Transformation of the blastula into an embryo possessing 3 germ layers

Morula (Developmental Vocabulary)

A solid mass of 16-64 cells formed by cleavage.