BIO exam CELLULAR REPRODUCTION

Cell Cycle

The series of phases (G1, S, G2, M) a cell goes through to grow and divide.

Interphase

Longest phase of the cell cycle; includes G1 (growth), S (DNA replication), and G2 (prep for division).

Cell Division

Process where a single cell divides to form two daughter cells.

Cytokinesis

Division of the cytoplasm following mitosis or meiosis.

Cell Plate

Structure that forms during cytokinesis in plant cells to divide the two daughter cells.

Cleavage

In animal cells, this is the process during cytokinesis where the cell membrane pinches in to split the cell.

Chromatin

Uncoiled DNA and proteins found in the nucleus during interphase.

Chromosomes

Tightly coiled DNA visible during cell division; carry genetic information.

Sister Chromatids

Two identical copies of a chromosome, joined at the centromere.

Centromere

The region that connects sister chromatids.

Histones

Proteins that DNA wraps around to form chromatin.

Karyotype

A picture of an individual's chromosomes used to detect genetic disorders.

Homologous Chromosomes

Pairs of chromosomes (one from each parent) that have the same genes at the same loci.

Asexual Reproduction

A form of reproduction where offspring arise from a single organism; no gametes involved.

Sexual Reproduction

Reproduction involving the fusion of gametes (sperm and egg), producing genetically diverse offspring.

Clone

A genetically identical copy of an organism produced through asexual reproduction.

Gametes

Sex cells (sperm and egg) that are haploid and combine during fertilization.

Haploid

A cell that contains one complete set of chromosomes (n). Example: gametes.

Diploid

A cell that contains two complete sets of chromosomes (2n). Example: body cells.

Fertilization

The process of a sperm cell fusing with an egg cell to form a zygote.

Zygote

A diploid cell formed after fertilization.

Meiosis

A type of cell division that produces four genetically unique haploid gametes.

Crossing Over

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

Nondisjunction

Error during meiosis in which chromosomes fail to separate properly, leading to genetic disorders (e.g., Down syndrome).

Autosomes

Chromosomes that do not determine sex (humans have 22 pairs).

Sex Chromosomes

Chromosomes that determine sex (X and Y in humans).

Cancer

Uncontrolled cell division due to mutations in genes that regulate the cell cycle.

Tumor

A mass of abnormal cells resulting from uncontrolled cell division.

Metastasis

The spread of cancer cells from the original site to other parts of the body.