Developmental Biology BIOL 3090 Lecture Flashcards

Vocabulary flashcards covering key terms and concepts from the Developmental Biology lecture notes, including stages of development, foundational theories, experimental models, and basic genetics.

Hox genes

Master regulatory genes that control body plan along the anterior-posterior axis; highly conserved homeobox-containing genes that specify segment identity during development.

Gastrulation

Stage in embryonic development when germ layers form and the body axes are established.

Neurulation

Process by which the neural tube forms from the ectoderm, initiating neural development.

Organogenesis

Formation of organs from germ layers during development.

Fertilization

Union of sperm and egg to form a zygote, initiating development.

Cleavage

Series of rapid mitotic divisions after fertilization that partition the zygote into smaller cells without growth.

Preformation

Theory that organisms develop from miniature preformed structures (homunculus) inside gametes.

Epigenesis

Theory that organisms develop progressively from undifferentiated cells; form emerges through developmental processes.

Cell Theory

Principle that all living organisms are composed of cells and that all cells arise from existing cells.

Somatic cells

Body cells that are not germ cells and do not directly transfer genetic information to offspring.

Germ cells

Reproductive cells (gametes) that transmit genetic information to offspring.

Mosaic development

Development where each cell’s fate is determined early; experimental removal/alteration can yield partial embryos (Roux-style evidence).

Regulative development

Development in which cells influence each other and can compensate or adjust fates after perturbation (Driesch).

Induction

Signaling interactions where one group of cells directs the differentiation of another group.

Spemann organizer

A region in the embryo that can induce neural tissue and organize body-axis patterning via induction.

Drosophila melanogaster (fruit fly)

A model organism prized for genetics and developmental studies due to short generation time and tractable genetics.

Xenopus laevis

A frog model organism widely used in vertebrate development research; useful for embryology experiments.

Danio rerio (zebrafish)

Vertebrate model with transparent embryos, facilitating live observation of development.

Mus musculus (mouse)

Mammalian model organism used to study genetics and development relevant to humans.

Caenorhabditis elegans

Nematode worm with a fixed cell lineage; simple, powerful for developmental biology studies.

Arabidopsis thaliana

Plant model organism (thale-cress) used for genetic and developmental studies in plants.

Sea urchins

Classic model for fertilization and early embryo development; accessible for experimental manipulation.

Genotype

The genetic makeup of an organism—the set of alleles it carries.

Phenotype

The observable traits of an organism, arising from the genotype and environment.

Allele

Alternative form of a gene at a given locus.

Heterozygous

Having two different alleles for a particular gene.

Homozygous

Having two identical alleles for a particular gene.

Recessive mutation

Mutation that manifests in the phenotype only when two copies are present (homozygous).

Dominant mutation

Mutation that affects the phenotype even when only one copy is present (heterozygous) or in homozygous form.

Brachiury (brachyury)

Semi-dominant gene mutation affecting tail development in vertebrate models; used as an example of semi-dominance in developmental genetics.