Chapter 10: Cell Cycle, Mitosis, and Meiosis

Vocabulary flashcards generated from lecture notes covering the cell cycle, mitosis, meiosis, stem cell types, and sources of genetic variation.

Cell cycle

A series of events that occur as one cell grows and divides into new cells.

G1 stage

Growth phase of the cell cycle where the cell grows, produces new proteins, and carries out normal functions.

S stage

Syntheses phase of the cell cycle where DNA is duplicated so each new cell can receive a copy.

G2 stage

Short growth phase of the cell cycle where the cell prepares for division.

M stage

Meiotic phase of the cell cycle where the cell divides into two daughter cells.

G0 stage

Functioning phase where some cells leave the cell cycle and stop dividing for days, years, or permanently.

Mitosis

Cell division that produces two daughter cells containing the same genetic information as the parent cell.

Interphase

The stage in the cell cycle when it is not dividing; the stage between miotic divisions.

Prophase (mitosis)

Stage of mitosis where centrioles move towards opposite poles, microtubules form the spindle, nuclear membrane forms the spindle, DNA coils into visible chromosomes, and chromatids are joined at the centromere.

Metaphase (mitosis)

Stage of mitosis where chromosome pairs line up along the equator of the cell and spindle fibres attach to centromeres.

Anaphase (mitosis)

Stage of mitosis where two chromatids separate at the centromere to become individual chromosomes and are pulled towards opposite poles.

Telophase (mitosis)

Stage of mitosis where chromosomes form two groups at opposite poles, new nuclear membranes form, two nuclei develop, spindle fibres disappear, and chromosomes uncoil back into chromatin.

Cytokinesis

The division of the cytoplasm.

Differentiation

The process by which cells become specialised to perform functions.

Stem cells

Cells that can differentiate into specialised cell types.

Totipotent stem cells

Stem cells that can create any of the types of cells necessary for embryonic development.

Pluripotent stem cells

Stem cells that can give rise to many, but not all, of the cell types necessary for foetal development.

Multipotent stem cells

Stem cells that can give rise to a limited number of other cell types, such as blood stem cells giving rise to red and white blood cells and platelets.

Gametes

Reproductive cells, specifically sperm and ova.

Diploid ($2n$)

Having two copies of each type of chromosome.

Haploid ($n$)

Having one copy of each type of chromosome.

Homologous chromosomes

Chromosome pairs that are similar in shape and carry genes influencing the same characteristics.

Meiosis

Cell division process that produces daughter cells containing half the chromosome number of the original cell.

Prophase I

First meiotic division stage during which the chromosomes become visible, the nuclear membrane breaks down, and the spindle forms.

Metaphase I

First meiotic division stage during which the homologous chromosomes line up on the equator.

Anaphase I

First meiotic division stage during which the homologous chromosomes move to opposite ends of the cell.

Telophase I and cytokinesis

First meiotic division stage during which the new nuclear membrane forms, producing two cells.

Prophase II

Second meiotic division stage during which the nuclear membrane disappears and the spindles form.

Metaphase II

Second meiotic division stage during which the chromosomes line up on the equator.

Anaphase II

Second meiotic division stage during which the daughter chromosomes move towards opposite ends of the cell.

Telophase II and cytokinesis

Second meiotic division stage during which the nuclear membrane forms, producing 4 new cells.

Crossing over

The interchange of the parts of the chromatids of a homologous pair of chromosomes during the first stage of meiosis.

Chiasma

The point at which crossing over occurs between chromatids.

Recombination

A changing of the order of alleles along a chromosome.

Non-disjunction

When one or more of the chromosome pairs fail to separate properly during meiosis.

Trisomy

Condition where an individual inherits three copies of a particular chromosome instead of the normal two, such as Down syndrome (trisomy 21).

Monosomy

Condition where an individual only has one copy of a chromosome instead of the normal two.

Random/independent assortment

The random combinations of the alleles due to allele pairs separating independently of one another.