15.1 Meiosis and the inheritance of genetic information via sexual reproduction

Flashcards covering key vocabulary and concepts from the meiosis lecture.

Meiosis

Process that generates haploid cells with half the genetic material of the diploid state.

Diploid

A cell or organism containing two sets of chromosomes (2n), one from each parent.

Haploid

A cell or organism containing one set of chromosomes (n).

Autosome

Any chromosome that is not a sex chromosome.

Sister chromatids

Two identical copies of a single chromosome that are connected by a centromere.

Meiosis I

The first division in meiosis, during which homologous chromosomes are separated.

Meiosis II

The second division in meiosis, during which sister chromatids are separated.

Prophase I

chromosome condensation, synapsis, and crossing over.

Metaphase I

homologous pairs align at the equator of the cell.

Anaphase I

homologous pairs are separated.

Telophase I

chromosomes decondense and the nuclear membrane reforms.

Prophase II

chromosomes condense.

Metaphase II

chromosomes line up at the equator.

Anaphase II

sister chromatids are separated.

Telophase II

nuclear envelope reforms and chromosomes decondense.

Independent Assortment

The random distribution of chromosomes into different cells during meiosis.

Genetic Recombination

The exchange of genetic material between homologous chromosomes during meiosis.

Synapsis

Pairing of homologous chromosomes during prophase I.

Crossing Over

Exchange of genetic material between homologous chromosomes.

Chiasma

Connection point between homologous pairs where crossing over occurs.

Aneuploid

Cells with an incorrect number of chromosomes.

purpose of meiosis

To reduce chromosome number and increase genetic diversity through sexual reproduction.

mitosis vs meiosis purposes

Mitosis = growth, repair and asexual reproduction

meiosis = sexual reproduction

mitosis vs meiosis products

mitosis = divides somatic cells into two identical diploid cells, meiosis = divides germ cells into four genetically diverse haploid cells.

somatic cells

Cells that make up the body, excluding germ cells involved in reproduction.

germ line cells

Cells that give rise to gametes, responsible for passing genetic information to offspring.

mitosis vs meiosis stages

mitosis = 4 (PMAT)
meiosis = 8 (PMAT x 2) - 2nd round more similar to mitosis as involves the separation of sister chromatids

why are meiosis daughter cells more likely to have chromosome segregation errors than mitosis

Meiosis involves two rounds of cell division and higher recombination rates, which can increase the risk of improper chromosome segregation during gamete formation.

why is meiosis 1 called reduction division

reduces chromosome numbers by half (from 46 to 23) as separates homologous chromosomes into different daughter cells

How does meiosis lead to genetic diversity

crossing over in Pro 1, independent assortment during meta 1, random fertilisation of genetically unique gametes