Meiosis and Sexual Reproduction

These flashcards cover key terms and concepts related to meiosis, gametes, genetic variation, and the distinctions between meiosis and mitosis.

Meiosis

A process of cell division that produces gametes with half the number of chromosomes as the parent cell.

Gametes

Reproductive cells (sperm and egg) that have half the number of chromosomes of somatic cells.

Haploid

A cell with one set of chromosomes (n), characteristic of gametes.

Diploid

A cell with two sets of chromosomes (2n), characteristic of somatic cells.

Crossing over

The exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Chiasma

A point where crossing over has occurred between homologous chromosomes.

Alleles

Different versions of a gene that may produce distinguishable phenotypic effects.

Synapsis

The pairing of homologous chromosomes during prophase I of meiosis.

Independent assortment

The random distribution of maternal and paternal chromosomes into gametes during meiosis.

Fertilization

The union of a sperm cell and an egg cell to form a zygote.

Zygote

A fertilized egg that contains genetic material from both parents.

Mitosis

A type of cell division that produces two identical daughter cells with the same number of chromosomes as the parent cell.

Genetic variation

Differences in DNA sequences among individuals, which contributes to diversity in populations.

Homologous chromosomes

Chromosome pairs, one from each parent, that are similar in shape and size and carry the same genes.

Cohesin protein

A protein that holds sister chromatids together until they separate during cell division.

Prophase I

The first stage of meiosis I where homologous chromosomes pair and crossing over occurs.

Anaphase I

The stage in meiosis I where homologous chromosomes are separated and move to opposite poles.

Telophase I

The final stage of meiosis I where each daughter cell has a haploid set of duplicated chromosomes.

Cytokinesis

The process of cell division that follows mitosis or meiosis, resulting in the separation of the cytoplasm into two cells.

Meiosis II

The second round of meiosis that separates sister chromatids, similar to mitosis, resulting in four haploid cells.

Evolutionary significance of genetic variation

Genetic variation allows for different alleles to be passed on, potentially increasing the success of offspring.