Mitosis and Meiosis Review

This set of flashcards covers key vocabulary and concepts from a Mitosis and Meiosis lecture, including cell cycle phases, specific meiotic events, and related chromosomal abnormalities.

Chromosome

Structure within the nucleus that comprises chromatin that contains DNA, the hereditary material.

Somatic cell

All the cells of a multicellular organism except the gamete-forming cells.

Sister chromatids

Identical copies of a single chromosome joined together by a region called the centromere.

Centromere

The specialized, constricted region of a chromosome that links sister chromatids together.

Mitosis

The period of the cell cycle at which the duplicated chromosomes are separated into identical nuclei.

G1

A cell-cycle phase and the first phase of interphase centered on cell growth during mitosis.

S

The second, or synthesis phase, of interphase during which DNA replication occurs.

G2

A cell-cycle phase and the third phase of interphase where the cell undergoes final preparations for mitosis.

Prophase

Stage where the nucleus disappears, chromosomes condense, and the mitotic spindle begins forming.

Pro Meta Phase

The second of the five phases that comprise the cell cycle and mitosis.

Metaphase

Stage where chromosomes line up at the metaphasic plate.

Ana Phase

The phase of the cell cycle where sister chromatids separate.

Telophase

Stage where chromosomes reach opposite poles and decondense, and a new nucleus envelope forms.

End result of mitosis

The production of $2$ cells with $46$ ($23$ pairs) chromosomes that are identical to the parent cell.

Cytokinesis

The division of the cytoplasm following mitosis to form two daughter cells.

Cleavage furrow

A constriction formed by the actin ring during animal-cell cytokinesis that leads to cytoplasmic division in animals, algae, and fungus.

Cell plate

A structure formed during plant-cell cytokinesis by Golgi vesicles fusing at the metaphase plate.

Homologous chromosomes

Chromosomes of the same length with genes in the same location.

Non-sister chromatids

Chromatids that inherit a trait each from a pair of identical chromosomes.

Haploid

Having exactly one complete, unpaired set of chromosomes.

Diploid

Two sets of chromosomes with each set inherited from each parent.

Crossing over

The exchange of genetic material between homologous chromosomes resulting in chromosomes that incorporate genes from both parents.

Genetic recombination

The process by which DNA pieces are broken and combined to produce new combinations of alleles.

Independent assortment

A fundamental genetic principle stating that the alleles for separate traits are passed to offspring independently of one another.

Gametes

A haploid reproductive cell or sex cell (sperm or egg).

Prophase 1

The first round of meiotic cell division, referred to as reduction division because resulting cells are haploid.

Metaphase 1

Stage where pairs of homologous chromosomes align randomly along the center of the cell.

Cancer

The cell cycle working too rapidly due to inhibitors stopping to work,

Non disjunction

The failure of synapsed homologs to completely separate and migrate to separate poles during the first cell division of meiosis.

Aneuploidy

The presence of an abnormal number of chromosomes in a cell, such as Downs or Turner syndrome.

Prophase 1

the first round of meiotic cell division; referred to as reduction division because the resulting cells are haploid

Metaphase 1

pairs of homologous chromosomes align randomly along the center of the cell

Anaphase 1

paired homologous chromosomes separate and are pulled to opposite poles of the cell by spindle fibers

Telophase 1

separated homologous chromosomes reach the opposite poles of the cell

End results of meiosis 1

the original cell divides into two genetically unique haploid cells

Meiosis 2

Chromosome number remains unchanged

Sister chromatids separate

Produces 4 diploid cell

Meiosis

Chromosome number halves

Homologues chromosomes separate

Produces 2 haploid cells

Metaphase 2

where chromosomes align in a single file along the center of the haploid cell spindle fibers attach preparing the sister chromatids to separate

Anaphase 2

the centromeres split, and the sister chromatids of each chromosome are pulled apart by spindle fibers toward opposite poles of the cell

Telophase 2

chromosomes reach opposite poles of the cell, decondense back into chromatin, and nuclear envelopes reform

End results of meiosis 2

4 genetically diverse haploid cells

Mitoisis

Purpose is to produce new cells

Mitosis occurs in diploid cells

1 round of cell division

Produces 2 new cells

3 Types of Cancer

Carcinomas, Sarcomas, Leukemia/Lymphomas

Define Non disjunction

the failure of synapsed homologs to completely separate and migrate to separate poles during the first cell division of meiosis

Define Aneuploidy and provide one example

the presence of an abnormal number of chromosomes in a cell. EG Downs, Turner syndrome

Joining two gametes together, one from each parent, is a process called

fertilization and results in a fertilized egg or zygote

Meiosis

Purpose is to produce gametes

Meiosis occurs in haploid cells

2 rounds of cell division

Produces 4 new cells

Does Meiosis multiply or divide its final chromosome count

Divides

Does mitosis multiply or divide its final chromosome count

Multiply