Bio621 Cell Division, Genetics, and Evolution Review

Comprehensive vocabulary flashcards covering cell biology, human reproduction, molecular genetics, evolutionary theory, and the classification of life based on lecture notebook notes.

Mitosis

The splitting of hereditary material within the parent nucleus which forms two daughter nuclei; used for growth and repair.

Cytokinesis

The division of the cytoplasm and organelles along with the daughter nuclei, dividing the parent cell into two daughter cells.

Interphase

The period between mitotic divisions including the $G_1$, $G_0$, $S$, and $G_2$ stages, during which the cell grows and replicates its DNA.

Oncogenes

Genes that control how fast or often cell division happens; if they are permanently 'switched on' by mutation, it results in cancer.

Supercoiling

The process in early prophase where the chromosomes shorten and thicken.

Asters

Star-shaped structures made of tubulin microtubules that extend from each centriole in animal cells during mitosis.

Meiosis

A type of cell division that ensures gametes are produced with a haploid number ($n$) of chromosomes by dividing the parent cell twice while replicating DNA only once.

Synapsis

The pairing process during Prophase I where each pair of sister chromatids lines up with their homologous pair to form a tetrad.

Independent Assortment

The random orientation and lining up of tetrads at the cell equator during metaphase I, which increases genetic variation.

Binary Fission

The asexual reproductive process in prokaryotes where a single circular chromosome replicates and the cell splits into two identical daughter cells.

Parthenogenesis

A form of asexual reproduction where unfertilized eggs develop into adults, as observed in honeybees.

Sertoli cells

Cells found within the seminiferous tubules that support, regulate, and nourish developing sperm.

Epididymis

A storage structure at the rear of each testis where immature sperm matures and becomes mobile.

Corpus luteum

A structure formed from a ruptured follicle during the luteal stage that releases progesterone to maintain the uterine lining.

Endometrium

The lining of the uterus that thickens with mucus and blood vessels to prepare for pregnancy.

Cleavage

The process of rapid mitotic division in the first week after fertilization where embryonic cells decrease in size but the total embryo size stays the same.

Gastrulation

The stage of embryonic development that leads to the formation of the three germ layers: ectoderm, endoderm, and mesoderm.

Differentiation

The changing of unspecialized embryonic cells into specialized cells, tissues, and organs that perform specific functions.

Neuralation

The process where ectoderm cells divide to form a neural tube, which eventually develops into the brain and spinal cord.

Chorion

The outermost embryonic membrane which surrounds all other membranes and develops into the placenta in humans.

Incomplete Dominance

A genetic inheritance pattern where both alleles contribute equally to the hybrid phenotype, resulting in a blended appearance.

Codominance

A pattern where two dominant alleles are expressed at the same time in the hybrid without blending, such as black and white feathers intermixed in chickens.

Transcription

The process where RNA polymerase uses a DNA template strand to create a complementary mRNA strand.

Exons

The coding regions of a gene that remain in the mRNA after introns have been removed during processing.

Silent Mutation

A point mutation that does not affect the cell's metabolism because the resulting amino acid in the protein remains the same or similar.

Non-disjunction

An error during meiosis (anaphase I or II) where entire chromosomes are added or missing in gametes.

Catastrophism

Georges Cuvier's theory that destructive forces like floods or earthquakes killed off groups of species, leading to extinctions.

Uniformitarianism

Charles Lyell’s idea that geological processes occur very slowly and that Earth is much older than 6,000 years.

Vestigial structures

Anatomical features, such as the human appendix, that are reduced in size and have no known function but resemble structures in other organisms.

Biogeography

The study of the geographic distribution of organisms and how species that evolve in one location spread to others.

Adaptive Radiation

The process where one ancestral species rapidly evolves into several different species adapted to various environmental niches.

Punctuated Equilibrium

An evolutionary model suggesting long periods of little change followed by rapid bursts of rapid change.

Hardy-Weinberg Principle

A mathematical formula ($p^2 + 2pq + q^2 = 1.00$) predicting that allele frequencies remain constant in genetic equilibrium under specific conditions.

Genetic Drift

Changes in allele frequencies in small populations due to chance events rather than natural selection.

Bottleneck Effect

A drastic reduction in population size due to a catastrophe that significantly reduces the genetic diversity of the gene pool.

Endosymbiotic Theory

The theory that eukaryotic organelles like mitochondria and chloroplasts originated as symbioses between separate single-celled prokaryotes.

Mycelium

A loosely branching network of densely packed hyphae that makes up the main body of a fungus, usually hidden underground.

Angiosperms

Seed-producing vascular plants that contain seeds within fruits and use flowers as reproductive organs.

Coelomates

Animals that possess a fluid-filled internal body cavity (coelum) within their mesoderm, allowing for more rigid structure and advanced organ systems.