Cell Cycle, Mitosis & Meiosis - Grade 10 Biology

This set covers the fundamental concepts of the cell cycle, the stages of mitosis, the process of meiosis, and key genetic terminology based on the Grade 10 biology curriculum.

Cell Cycle

The series of events a cell goes through to grow, copy its DNA, and divide into new cells.

G1 phase

The stage where the cell grows, makes organelles, and carries out normal functions; characterized as growth and normal cell activity.

S phase

The phase of interphase where DNA replication occurs and each chromosome is replicated.

G2 phase

The phase where the cell checks its DNA and prepares for mitosis.

M phase

The stage of the cell cycle consisting of mitosis (division of the nucleus) followed by cytokinesis (division of the cytoplasm).

DNA

Deoxyribonucleic acid; the molecule that carries genetic information.

Chromosome

A coiled structure composed of DNA and proteins.

Chromatid

One half of a copied chromosome.

Sister chromatids

Two identical copies of a chromosome that are joined together at the centromere.

Centromere

The specific point where sister chromatids are attached to one another.

Homologous chromosomes

A matching chromosome pair, with one from each parent, that carry the same genes.

Diploid ($2n$)

A cell containing a full set of chromosomes, such as body cells.

Haploid ($n$)

A cell containing half the chromosome number, such as gametes.

Mitosis

Nuclear division producing two genetically identical daughter cells with the same chromosome number as the parent cell, used for growth and repair.

PMAT

The acronym for the stages of mitosis: Prophase, Metaphase, Anaphase, and Telophase.

Prophase

The stage of mitosis where chromosomes condense and become visible, the nuclear membrane breaks down, and spindle fibres form.

Metaphase

The stage of mitosis where chromosomes line up across the equator of the cell and spindle fibres attach to centromeres.

Anaphase

The stage of mitosis where sister chromatids separate and are pulled to opposite poles of the cell.

Telophase

The stage of mitosis where new nuclear membranes form around each set of chromosomes and the chromosomes uncoil.

Cytokinesis

The process where the cytoplasm divides, resulting in two separate genetically identical daughter cells.

Meiosis

Cell division that produces gametes, reduces the chromosome number by half, and creates genetic variation.

Meiosis I

The portion of meiosis where homologous chromosomes pair up, crossing over can occur, and homologous chromosomes separate.

Meiosis II

The portion of meiosis where sister chromatids separate, a process similar to mitosis.

Crossing over

The exchange of DNA between homologous chromosomes that creates new combinations of alleles and increases genetic variation.

Body cell chromosome number

In humans, this is the diploid ($2n$) number of $46$.

Gamete chromosome number

In humans, this is the haploid ($n$) number of $23$.

Zygote

A fertilized egg that is diploid ($2n$) with $46$ chromosomes after fertilization restores the number ($23 + 23 = 46$).