Biology Cell Division Test

Cell Cycle

The sequence of growth and division that cells go through.

Purpose of the cell cycle

For growth, reproduction and repair depending on the organism and type of cell.

Mitosis

A type of cell division that results in two identical daughter cells.

Meiosis

A special type of division that reduces the chromosome number by half, producing gametes (sperm and eggs).

Chromosome

A structure made of DNA and proteins that carries genetic information.

Chromatin

The loose form of DNA found in the nucleus during interphase.

Chromatid

One of two identical halves of a duplicated chromosome.

Centromere

The region where two sister chromatids are attached.

Centriole

The 'pole' of the cell, where the mitotic spindle moves before it begins to send out the microtubules.

Kinetochore

The connection point of a chromatid and microtubule.

Microtubule

The structure that originates from the mitotic spindle and moves chromosomes around including aligning them on the metaphase plate.

Metaphase plate

The 'equator' of the cell.

Cytokinesis

The process of dividing the cytoplasm and organelles between daughter cells.

Diploid (2n)

Cells with two sets of chromosomes (e.g., human body cells).

Haploid (n)

Cells with only one set of chromosomes (e.g., sperm and egg cells).

Gametes

Reproductive cells (sperm and egg) produced through meiosis.

Zygote

A fertilized egg, formed when two gametes combine.

Interphase

The longest phase where the cell grows and prepares for division.

G1 phase

Cell growth and normal functions.

S phase

DNA replication.

G2 phase

Preparation for mitosis.

M Phase (Mitosis/Meiosis)

The stage of actual division.

Prophase

Chromatin condenses into chromosomes; nuclear membrane dissolves.

Metaphase

Chromosomes align in the center of the cell.

Anaphase

Sister chromatids separate and move to opposite poles. Centromere breaks down. Equal amount, equal timing.

Telophase

Characteristic peanut shape in animal cells, chromosomes decondense; nuclear membranes reform. Organelles start to move to opposite ends for separation.

Checkpoints

Determine if the DNA was replicated properly, the cell is large enough, the correct proteins were made, and chromosomes are aligned properly and have separated.

Apoptosis

Cell death initiated to protect the organism if checkpoints are missed or repairs not completed.

G0 phase

A phase where specialized and functioning cells, like neurons, do not undergo mitosis.

Nondisjunction

Chromosomes do not separate evenly resulting in an uneven number of chromosomes in each daughter cell, happening in mitosis or meiosis, but always during anaphase.