Histology Notes on the Cell Cycle

These flashcards cover key vocabulary related to the cell cycle, mitosis, and meiosis based on the histology lecture notes.

Cell Cycle

A sequence of events in which a cell transitions from its current state until it divides into two daughter cells.

Interphase

The stage where cells prepare for division through protein, RNA, and DNA replication, comprised of G1, S-phase, G2, and G0 phases.

G1 Phase

The longest phase of interphase where postmitotic cells grow by synthesizing proteins and RNA.

S-phase

The phase characterized by DNA replication, histone synthesis, and beginning of centrosome duplication.

G2 Phase

The phase where the cell prepares for mitosis by accumulating proteins and checking for errors in duplicated chromosomes.

M-Phase

The actual phase where cell division occurs, resulting in two daughter cells with identical chromosomes.

Prophase

The phase of mitosis characterized by the condensation of chromatin into chromosomes and the disappearance of the nuclear envelope.

Metaphase

The phase of mitosis where chromosomes move to the equatorial plane and attach to the mitotic spindle.

Anaphase

The phase of mitosis where chromatids are pulled apart by the mitotic spindle.

Telophase

The final phase of mitosis where chromosomes decondense, the nuclear envelope reappears, and a contractile ring forms.

Meiosis

A specialized form of cell division that produces four haploid cells from one diploid cell, allowing for genetic variation.

Synapsis

The pairing of homologous chromosomes during meiosis.

Chiasma

The point of contact between homologous chromosomes during crossing over.

Crossing Over

The exchange of genetic segments between homologous chromosomes, contributing to genetic variation.

G1/S Checkpoint

The checkpoint that assesses cell size, nutrient availability, and DNA integrity before entering S phase.

p53

A tumor suppressor gene that monitors DNA damage and can initiate apoptosis if damage is irreparable.

Karyotype

The arrangement of chromosomes in a human cell, consisting of 23 pairs, where pair 23 are the sex chromosomes.

Haploid

A cell that has half the number of chromosomes, such as gametes resulting from meiosis.

Cyclins and CDKs

Regulatory proteins that control the progression of the cell cycle by phosphorylating target proteins.

Cytokinesis

The process during cell division in which the cytoplasm splits to form two daughter cells.