BIOL 111 - Lecture 17: The Cell Cycle I Vocabulary Flashcards

Vocabulary practice flashcards covering cell division, eukaryotic and prokaryotic genetics, chromosome structure, ploidy states, interphase stages, and mitotic subphases from BIOL 111 Lecture 17.

Ploidy

The number of complete sets of chromosomes present in a cell or organism.

Diploid ($2n$)

A cellular state where cells contain two complete sets of chromosomes, receiving one copy from each biological parent.

Haploid ($n$)

A cellular state where cells contain only one copy of each chromosome.

Somatic Cells

Diploid ($2n$) cells that compose the physical body of a multicellular organism.

Gametes

Specialized haploid ($n$) reproductive cells, such as egg and sperm cells.

Homologous Chromosomes

Chromosomes that pair up during cellular reproduction, sharing the same genes and structural characteristics.

Heterologous Chromosomes

Chromosomes within a genome that do not have an identical matching pair, such as human male $X$ and $Y$ sex chromosomes.

Karyotype

A laboratory-produced image displaying all of an organism's chromosomes organized in pairs.

Plasmids

Small, circular, non-chromosomal DNA molecules found in prokaryotes that carry additional genetic information non-essential for normal growth and can be exchanged via gene transfer.

Nucleosome

A structural unit of eukaryotic chromatin consisting of a short segment of DNA wrapped around a core of 8 histone proteins.

Linker DNA

The stretch of DNA that connects individual nucleosomes together, resembling string between beads.

Interphase

The non-dividing stage of the cell cycle during which the cell functions normally, encompassing $G_1$, $S$, and $G_2$ phases.

$G_1$ Phase (First Gap Phase)

The first phase of interphase in which the cell is biologically active but shows no visible signs of preparing for division.

$S$ Phase (DNA Synthesis Phase)

The stage of interphase during which DNA replication occurs, generating identical copies of chromosomes joined at the centromere.

Sister Chromatids

Two identical copies of a duplicated chromosome connected at the centromeric region.

$G_2$ Phase (Second Gap Phase)

The sub-phase of interphase where organelles replicate, centrosomes form, cytoplasm expands, and the cell double-checks preparations before cell division.

Mitosis (M Phase)

The phase of the cell cycle during which a cell divides its copied genetic material into two identical groups to form two daughter cells.

Prophase

The initial stage of mitosis characterized by chromosome condensation, disappearance of the nucleolus, migration of centrosomes to poles, and formation of spindle microtubules.

Prometaphase

The phase of mitosis during which the nuclear envelope breaks down and spindle microtubules attach to kinetochores located on sister chromatids.

Kinetochore

A protein complex that develops in the centromere region of sister chromatids to serve as an attachment point for spindle microtubules.

Metaphase

The mitotic phase where chromosomes complete migration and line up along the metaphase plate in the center of the cell.

Anaphase

The phase of mitosis in which sister chromatids separate into daughter chromosomes and are pulled toward opposite poles of the spindle apparatus.

Telophase

The final phase of nuclear division where chromosomes reach opposite poles, decondense, and new nuclear envelopes re-form.

Cytokinesis

The division of the cell's cytoplasm following telophase, resulting in two distinct daughter cells.

Cell Plate

A structure formed during plant cell cytokinesis by the fusion of Golgi-derived vesicles along the midline of the cell.

Cleavage Furrow

An inward constriction formed in animal, fungal, and slime mold cells during cytokinesis by the contraction of an actin and myosin filament ring.