Biology Unit 5: Cell Cycle & Meiosis (Simplified Vocabulary)

Cell Division

When one cell divides to make two new daughter cells.

Asexual reproduction

Reproduction with one parent that makes identical offspring (clones).

Sexual reproduction

Reproduction with two parents that join cells to make a unique organism.

Chromosomes

Threadlike structures in the nucleus that carry DNA and genes.

Chromatin

Unpacked, loose DNA wrapped around proteins inside the nucleus.

Cell cycle

The life steps of a cell: grow, prepare, and divide.

Interphase

The resting and growth phase before a cell divides.

Mitosis

The division of the cell nucleus.

Cytokinesis

The cutting/division of the cell liquid (cytoplasm) to make two cells.

Chromatids

The two matching "sister" arms of a copied chromosome.

Centromere

The center button that holds two sister chromatids together.

Prophase

First phase of mitosis; DNA packs into visible X shapes.

Metaphase

Phase of mitosis where chromosomes line up in the Middle.

Anaphase

Phase of mitosis where chromosomes get pulled Away to opposite sides.

Telophase

Phase of mitosis where Two new nuclei form around the DNA.

Cancer

A disease where body cells lose control and cannot stop dividing.

Gamete

A sex cell (sperm or egg).

Somatic cell

A regular body cell (like skin, muscle, or bone).

Diploid

A cell with a Double/full set of chromosomes (pairs from both parents).

Haploid

A cell with only a Half set of chromosomes (single set).

Homologous chromosomes

A pair of matching chromosomes (one from mom, one from dad).

Tetrad

A group of 4 chromatids lined up together in meiosis.

Crossing-over

When matching chromosomes swap pieces of DNA to make variation.

Karyotype

A picture map of all a person's chromosomes arranged by size.

Autosomes

Regular body chromosomes that do NOT determine sex (pairs 1-22).

Zygote

A fertilized egg cell (sperm + egg united).

Sex chromosomes

The pair of chromosomes that determine biological sex (X and Y).

Nondisjunction

An error in cell division where chromosomes fail to separate correctly.