BIO 09 Module 2: Genetic Control of Systems, Cell Cycle, and Function Flashcards

Vocabulary flashcards covering key terms and concepts related to cell structures, chromosome morphology, the cell cycle, mitosis, meiosis, and gametogenesis based on BIO 09 Module 2.

Mitosis

An equational division process that partitions genetic material into two daughter nuclei identical to the parent cell.

Meiosis

A reductional division process that produces gametes or spores containing a single haploid set of chromosomes.

Chromatin

Uncoiled, dispersed fibers composed of DNA and protein found in the nucleus during non-divisional phases of the cell cycle.

Chromosomes

Coiled and condensed chromatin structures that serve as vehicles to transmit genetic information during cell division.

Nucleolus organizer region (NOR)

Portions of DNA within the nucleus that encode ribosomal RNA (rRNA).

Nucleoid

An unenclosed region in prokaryotic cells where genetic material is present as a long, compacted, circular DNA molecule.

Cytosol

The non-particulate, colloidal material within the cytoplasm that surrounds the organelles.

Cytoskeleton

An internal network providing structural support within eukaryotic cells, composed of microtubules made of tubulin and microfilaments derived from actin.

Smooth ER

The portion of the endoplasmic reticulum responsible for fatty acid and phospholipid synthesis.

Rough ER

Endoplasmic reticulum studded with ribosomes where the translation of mRNA into protein occurs.

Centrioles

A pair of complex structures in the centrosome composed of tubulin microtubule arrays that organize spindle fibers during mitosis and meiosis.

Centromere

A constricted region on a chromosome that joins sister chromatids and whose location determines the physical appearance of the chromosome.

Metacentric

A chromosome designation given when the centromere is located in the middle.

Submetacentric

A chromosome designation given when the centromere is located between the middle and the end.

Acrocentric

A chromosome designation given when the centromere is located close to one end.

Telocentric

A chromosome designation given when the centromere is located at the very end.

p arm

The shorter arm of a chromosome, named 'p' for petite.

q arm

The longer arm of a chromosome, located below the centromere.

Diploid number ($2n$)

The condition where somatic cells of a species contain two complete sets of chromosomes ($46$ in humans).

Homologous chromosomes

Chromosomes that pair up during meiosis and share identical length, centromere placement, and gene loci.

Karyotype

A visual display created by photographing metaphase chromosomes, cutting them out, and matching them up into pairs.

Haploid number ($n$)

One-half of the diploid number, representing a single complete set of chromosomes found in gametes or spores.

Genome

The total genetic information contained in a single haploid set of chromosomes, including all genes and non-coding DNA.

Locus

The specific site along a chromosome where a particular gene is located.

Cell cycle

The sequence of biological events occurring from the completion of one cell division to the completion of the next.

Interphase

The interval between cell divisions characterized by cell growth, normal function, and DNA replication during S phase.

$G_0$ phase

A quiescent, non-dividing state entered when a cell withdraws from the $G_1$ phase of the cell cycle.

Karyokinesis

The precise process of nuclear division that partitions genetic material into two daughter nuclei.

Cytokinesis

The cytoplasmic division process following karyokinesis that yields two distinct daughter cells.

Cohesin

A multi-subunit protein complex that holds sister chromatids together.

Prometaphase

The phase of mitosis during which chromosomes move toward the equatorial plane or metaphase plate.

Kinetochore

Multilayered plates of proteins associated with the centromere where spindle fibers attach to the chromosome.

Separase

An enzyme that degrades the cohesin complex to permit sister chromatid separation.

Shugoshin

A protein (meaning 'guardian spirit') that protects centromeric cohesin from degradation until anaphase.

Disjunction

The separation of sister chromatids or homologous chromosomes during anaphase.

Nondisjunction

An error during meiotic division where chromosome separation fails, leading to conditions such as Down syndrome.

Synapsis

The pairing of homologous chromosomes during prophase I of meiosis to form a bivalent or tetrad.

Spermatogenesis

The meiotic pathway in male animals occurring in the testes that generates four functional spermatozoa from a primary spermatocyte.

Oogenesis

The meiotic pathway in female animals occurring in the ovaries that produces one functional ovum and polar bodies.

Folded-Fiber Model

Ernest DuPraw's model stating that metaphase chromatids consist of tightly coiled single fibers of double-stranded DNA and protein condensed from interphase chromatin.