Cell Division: Mitosis and Meiosis

Vocabulary flashcards covering the key terms, stages, and concepts of cell division, mitosis, and meiosis from the lecture notes.

M-Phase (Cell Division)

The phase where the cell splits into two new daughter cells.

Daughter Cells

Two new cells produced after cell division.

Parent Cell

The cell that divides to form daughter cells.

G0 Phase

A resting phase where the cell is not actively dividing.

Checkpoints

Control points that ensure the cell cycle is completed accurately.

Apoptosis

Programmed cell death that removes damaged or unnecessary cells.

Spindle Fibers

Thin protein strands that help separate chromosomes during cell division (mitosis and meiosis).

Centrioles

Cylindrical structures in animal cells that organize and anchor the spindle fibers during cell division.

Centromere

The region where two sister chromatids are joined together, which also serves as the attachment point for spindle fibers.

Chromosome

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

Chromatid

One of the two identical copies of a replicated chromosome joined at the centromere.

Chromatin

The uncoiled, threadlike form of DNA found in the nucleus during Interphase (when the cell is not dividing).

Diploid ($2n$)

A cell that contains two complete sets of chromosomes—one set from each parent ($46$ chromosomes in humans).

Haploid ($n$)

A cell that contains only one set of chromosomes ($23$ chromosomes in human gametes).

Mitosis

The process by which body (somatic) cells divide to form two new identical cells, each with the same number of chromosomes as the original cell, helping the body grow, repair damaged tissues, and replace worn-out cells.

Prophase (Mitosis)

Chromosomes condense and become visible; the nuclear membrane breaks down; the centrosomes move to opposite poles of the cell.

Metaphase (Mitosis)

Chromosomes line up in the middle of the cell; spindle fibers attach to centromeres.

Anaphase (Mitosis)

Sister chromatids separate and move toward opposite poles.

Telophase (Mitosis)

Chromosomes decondense into chromatin and the nuclear membrane reforms.

Meiosis

A special type of cell division that produces sex cells or gametes (sperm and egg cells) for sexual reproduction, reducing the chromosome number of a diploid parent cell by half, forming four genetically unique haploid daughter cells.

Prophase I

The stage of Meiosis I where synapsis and crossing-over occur.

Crossing-over

Homologous chromosomes pair up and exchange segments of DNA.

Synapsis

Chromosomes align closely, which allows for crossing-over.

Metaphase I

Homologous pairs align at the equator.

Anaphase I

Homologous chromosomes separate.

Telophase I

Two haploid cells are formed.

Prophase II

The stage of Meiosis II where chromosomes condense.

Metaphase II

The stage of Meiosis II where chromosomes align at the equator.

Anaphase II

The stage of Meiosis II where sister chromatids separate.

Telophase II and Cytokinesis

The final stage of Meiosis II where four haploid cells form.

Cytokinesis (Animal vs. Plant Cells)

In animal cells, cytokinesis occurs through a cleavage furrow, whereas in plant cells, it occurs through the formation of a cell plate.