Cell Cycle - Vocabulary Flashcards (Video Notes)

Vocabulary flashcards covering key terms from the cell cycle lecture notes.

Cell cycle

A series of ordered stages in which a parent cell grows, duplicates DNA, and divides to form two daughter cells.

Interphase

The longest phase of the cell cycle during which the cell grows and DNA is replicated in preparation for division.

G1 phase (Gap 1)

Cell growth and maturation; preparation for DNA replication.

S phase (Synthesis)

DNA is replicated, doubling the chromosome count.

G2 phase (Gap 2)

Further growth and preparation for mitosis or meiosis.

M phase

Mitosis and cytokinesis; division of the nucleus and cytoplasm.

G0 phase

A resting state where cells may pause division instead of progressing; some cells stay here permanently.

G1 to S checkpoint

Assesses size, nutrients, growth signals, and DNA integrity before DNA replication.

G2 checkpoint

Assesses DNA integrity and whether DNA replication is complete before mitosis.

M checkpoint

Assesses chromosome alignment and spindle attachment before anaphase.

Checkpoint significance

Quality-control stage that can stop the cycle if DNA is damaged or conditions are unfavorable.

Mitosis

Division of the nucleus into two genetically identical nuclei; part of M phase.

Meiosis

Special cell division for gametes that produces four genetically unique haploid cells.

Haploid (n)

Cells containing one set of chromosomes.

Diploid (2n)

Cells containing two sets of chromosomes.

Autosomes

Chromosome pairs 1–22; carry non-sex traits.

Sex chromosomes

Chromosome pair 23; determine sex (XX in females, XY in males in humans).

Chromosome

A long DNA molecule with many genes; organized during division.

Chromatid

One of the two identical copies of a replicated chromosome; together they form sister chromatids.

Sister chromatid

Identical copies of a chromosome connected at the centromere; separated during anaphase.

Centromere

Region joining sister chromatids and where kinetochores attach.

Kinetochore

Protein structure at the centromere that attaches microtubules during mitosis.

Chromatin

DNA wrapped around histones; becomes condensed chromosomes during mitosis.

Histones

Proteins around which DNA winds to form chromatin.

Telomere

Protective end caps of chromosomes that shorten with divisions.

Prophase

Chromosomes condense; nuclear envelope breaks down; centrioles migrate; spindle forms.

Prometaphase

Nuclear envelope breaks down; spindle fibers attach to kinetochores and chromosomes begin moving.

Metaphase

Chromosomes align at the metaphase plate; kinetochores attached to spindle fibers from opposite poles.

Anaphase

Sister chromatids separate and move to opposite poles; cell elongates.

Telophase

Nuclear envelope reforms; chromosomes de-condense; spindle breaks down; cytokinesis begins.

Cytokinesis

Division of the cytoplasm; splits into two daughter cells; differs in plant and animal cells.

Cleavage furrow

Indentation of the animal cell membrane that deepens to split the cell during cytokinesis.

Cell plate

Structure that forms between plant daughter nuclei to develop separating cell walls.

PMAT

The order of mitotic stages: Prophase, Metaphase, Anaphase, Telophase (followed by cytokinesis).

Crossing over

Exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Synapsis

Pairing of homologous chromosomes during prophase I to form tetrads.

Tetrad

Group of four chromatids formed by synapsis of homologous chromosomes in meiosis I.

Meiosis I

Homologous chromosomes separate; results in two haploid cells; may include crossing-over.

Meiosis II

Sister chromatids separate; yields four haploid daughter cells.

Aneuploidy

Abnormal number of chromosomes in a cell; can cause syndromes such as trisomies or monosomies.

Down syndrome (trisomy 21)

Nondisjunction leading to three copies of chromosome 21; intellectual and physical features.

Turner syndrome

Monosomy X (one X) in females; short stature and infertility among features.

Klinefelter syndrome

XXY karyotype; male with an extra X; infertility and other traits.

XYY syndrome

Male with an extra Y chromosome; effects vary.

Cancer

Loss of cell cycle control leading to uncontrolled division, tumors, invasion, and metastasis.

Sickle cell anemia

Point mutation in the hemoglobin gene causing abnormal red blood cells and oxygen transport issues.

Importance of cell cycle

Repairs and renews damaged cells; supports growth, development, and reproduction.

Plant vs animal cytokinesis difference

Plants form a cell plate to build new cell walls; animals form a cleavage furrow to split the cell.