Sexual Reproduction and Meiosis

These flashcards cover key terminology and concepts related to sexual reproduction and meiosis, aiding in the understanding of cell division and genetic variation.

Mitosis

A type of cell division that creates two identical diploid cells. It is responsible for replicating nearly all of our body's cells.

Meiosis

A type of cell division that produces gametes, resulting in four haploid cells through two rounds of division.

Zygote

A fertilized egg formed from the fusion of male and female gametes; it is diploid.

Gametes

Reproductive cells (sperm and oocytes) that are haploid and fuse during fertilization to create a zygote.

Haploid

A cell that contains one complete set of chromosomes; gametes are haploid.

Diploid

A cell that contains two complete sets of chromosomes, one from each parent; human body cells are diploid.

Homologous chromosomes

Pairs of chromosomes in a diploid cell that have the same genes but possibly different alleles.

Sister chromatids

Identical copies of a chromosome, connected by a centromere, produced during DNA replication.

Prophase I

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

Synapsis

The pairing of homologous chromosomes during prophase I of meiosis, allowing for crossing over.

Crossing over

The exchange of genetic material between non-sister chromatids during prophase I of meiosis, increasing genetic diversity.

Chiasmata

The points where crossing over occurs between homologous chromosomes during prophase I.

Independent assortment

The random distribution of maternal and paternal chromosomes into gametes during meiosis, leading to genetic variation.

Cytokinesis

The process of cell division that occurs at the end of mitosis or meiosis, dividing the cytoplasm into two daughter cells.

Meiosis II

The second meiotic division, similar to mitosis, that separates sister chromatids, resulting in four haploid cells.

Reduction division

Another term for meiosis I, referring to the halving of chromosome number from diploid to haploid.

Gametes

Specialized reproductive cells (sperm and egg) that are haploid and combine during fertilization to form a diploid zygote.

Telophase II

The final stage of meiosis II where chromosomes de-condense and the nuclear envelope reforms, resulting in four haploid cells.