Biological Science: Genes, Development, and Evolution

These flashcards cover key concepts regarding the genetic regulatory cascades, embryonic development stages, and the roles of various genes in biological science.

Maternal effect genes

Genes that encode morphogens defining the anterior-posterior axes of early embryos.

Gap genes

Genes that control the formation of large body regions along the anterior-posterior axis.

Pair-rule genes

Genes expressed in alternating bands that control the formation of individual segments.

Segment polarity genes

Genes that establish subregions within each segment.

Hox genes

Genes that specify the identity of body parts that will develop from segments.

Effector genes

Genes that lead to development through directing cell proliferation, death, movement, and differentiation.

Blastomeres

Cells created during the cleavage stage of embryonic development.

Blastula

A mass of blastomeres formed during the early stages of embryonic development.

Trophoblast

The exterior layer of the blastocyst that helps form the placenta.

Gastrulation

The process during development where extensive and organized cell movements rearrange cells into a gastrula.

Germ layers

Three embryonic layers—ectoderm, mesoderm, and endoderm—that give rise to all organs and tissues.

Organogenesis

The stage of development during which organs and tissues are formed from the embryo.

Somites

Transient structures that give rise to muscle, skin, and skeleton during development.

Sonic hedgehog

A signaling protein crucial for limb development, produced by cells in each limb bud.

Evolutionary developmental biology (evo-devo)

The study of changes in developmentally important genes and their impact on evolution.