Meiosis Practice Flashcards

Vocabulary-style flashcards covering the concepts of Meiosis, genetic diversity, cell types, and chromosomal abnormalities based on Science 9 lecture notes.

Sexual reproduction

A process that requires 2 parents and produces offspring that are genetically different from each other, from either parent, and from any other member of their species.

Genetic variation

The variation or inherited genetic differences in a species produced through sexual reproduction, which randomly sorts DNA.

Somatic cells

Body cells that reproduce through mitosis and make up the majority of an organism’s cells; in humans, these cells have $46$ chromosomes ($2n$).

Gametic cells

Also called gametes or sex cells, these cells reproduce through meiosis and in humans have $23$ chromosomes ($n$).

Meiosis

The process that produces gametes (eggs and sperm) with half the number of chromosomes as a somatic cell.

Diploid

The chromosome number ($2n$) referring to two sets of chromosomes; in humans, this number is $46$.

Haploid

The chromosome number ($n$) representing a single set of chromosomes; in humans, this number is $23$.

Gamete

Specialized cells that carry the haploid ($n$) chromosomes; females produce eggs and males produce sperm.

Fertilization

Occurs when the egg cell is penetrated by the sperm cell and the haploid genetic information is combined.

Zygote

The resulting diploid cell formed after fertilization occurs.

Embryo

The stage of development reached after the zygote undergoes mitosis and cell division.

Meiosis I

The first part of meiosis where the pair of homologous chromosomes separate to opposite poles, resulting in $2$ haploid cells.

Meiosis II

The second part of meiosis where sister chromatids are pulled to opposite poles, resulting in $4$ haploid cells.

Homologous chromosomes

A pair of chromosomes (one from each parent) that are the same size, shape, and have genes in the same location.

Crossing Over

A process in late prophase or metaphase where non-sister chromatids exchange segments of DNA, resulting in genetic variation.

Independent Assortment

When homologous pairs of chromosomes separate at the equator and move to opposite poles independently of each other.

Spermatogenesis

The formation of gametes resulting in four cells with cytoplasm and organelles equally divided between them, which may develop into mature sperm.

Oogenesis

The formation of gametes resulting in an unequal division of cytoplasm and organelles, creating one large egg and three cells that degenerate.

Chromosome Mutations

Changes to chromosomes that can be partial (deletion, duplication, inversion, translocation) or whole (non-separation of homologous chromosomes or sister chromatids).

Karyotype

A picture used to show chromosomes, where homologous pairs are identified by size, centromere locations, and banding patterns.

Down Syndrome

A genetic disorder characterized by having an extra chromosome $21$, identifiable through karyotyping.