Meiosis

gamete

human sex cell

egg

female sex cell

sperm

male sex cell

Haploid

a cell with one set of chromosomes

Diploid

a cell with two chromosomes

crossing over

In genetics, __________ is the exchange of genetic material between homologous chromosomes during meiosis. This process results in genetic variation among offspring.

meiosis

a type of cell division that produces gametes with half the number of chromosomes as the parent cell. It involves two rounds of division resulting in four daughter cells, each genetically unique. Meiosis is essential for sexual reproduction in eukaryotes.

homogolous chromosomes

_________________ are pairs of chromosomes that have the same genes in the same order, one from each parent. They are similar in size and shape.

zygote

the first cell after fertilization is completed

somatic cell

any other cell in the body besides sex cells (body cells)

sex chromosomes

__________ determine an individual's biological sex. In humans, females have two X chromosomes, while males have one X and one Y chromosome.

Meiosis 1

Process in cell division where homologous chromosomes separate, resulting in two daughter cells with half the number of chromosomes as the parent cell.

Meiosis 2

Division of a haploid cell into four haploid daughter cells, each with half the number of chromosomes as the original cell.Occurs after Meiosis I.

A sex cell has____ chromosomes

23

Independant Asortment

The principle stating that during gamete formation, the segregation of alleles for one gene does not influence the segregation of alleles for another gene.

Gametes combine, making the total number of chromosomes…

46

characteristics of diploid cells

-all somatic cells

-contain total number of chromosomes

-humans- _____ number is 46

-Represented by 2N

-2 Sets of chromosomes

Characteristics of Haploid cells

-All gametes

-Contain half the diploid number of chromosomes

-In humans _______ is 23

- Represented by N

-One set of chromosomes

Stages of Meiosis

One replication, two divisions

At the end of Meiosis there are a total of

4 Haploid cells

Meiosis 1

Prophase 1, Metaphase 1, anaphase 1, telophase 1

Prophase 1

First stage of meiosis. Chromosomes condense, pair up in homologous pairs, and crossing over occurs between them. Nuclear envelope breaks down.

Metaphase 1

Stage of meiosis where homologous chromosomes line up at the cell's equator. Crossing over occurs, leading to genetic variation.

Anaphase 1

the stage in meiosis where homologous chromosomes separate and move to opposite poles of the cell, reducing chromosome number by half.

telophase 1

the final stage of meiosis 1 where the chromosomes reach the poles of the cell, nuclear envelopes reform, and cytokinesis occurs, resulting in two haploid daughter cells.

Meiosis 2 stages

P2, M2, A2, T2

Prophase 2

Phase of meiosis where chromosomes condense, nuclear envelope breaks down, spindle fibers form, and homologous chromosomes do not pair up.

Metaphase 2

Stage of meiosis where chromosomes align at the equator of the cell, ready to be separated into individual chromatids during anaphase 2.

Anaphase 2

Phase of meiosis where sister chromatids separate and move towards opposite poles of the cell, pulled by spindle fibers. Results in haploid daughter cells.

Telophase 2

Telophase 2 is the final stage of meiosis where the chromosomes reach the poles of the cell, nuclear envelope reforms, and cytokinesis occurs, resulting in four haploid daughter cells.

Cytokenisis

Process in cell division where the cytoplasm divides, forming two daughter cells.Occurs after telophase and completes the cell cycle.

Gametogenesis

the process of forming gametes (sperm and egg cells) through meiosis. It occurs in the gonads (testes and ovaries) and is essential for sexual reproduction.

Spermatogenesis

the process by which sperm cells are produced in the male testes through a series of mitotic and meiotic divisions. It involves the differentiation of spermatogonia into mature sperm cells.

Oogenesis

the process of female gamete formation where a diploid oogonium undergoes meiosis to produce a single haploid egg cell.

Meiosis is a form of

Genetic variation

Plants