Chapter 12: Meiosis and Sexual Reproduction

Sexual Reproduction

Reproductive mode by which offspring arise from two parents and inherit genes from both.

Alleles

Forms of a gene with slightly different DNA sequences; may encode diffrernt versions of the gene’s product.

Fertilization

Fusion of two gametes to from a zygote.

Gamete

Mature, haploid reproductive cell; e.g, a sperm.

Germ Cell

Immature reproductive cell that gives rise to haploid gametes when it divides.

Haploid

Having one copy of each type of chromosome (n).

Meiosis

Nuclear division processs that halves the chromosome number. Required for sexual reproduction. 

Zygote

Diploid cell that forms when two gametes fuse; the first cell of a new individual.

Crossing over

Process by which homologous chromosomes exchange corresponding segments of DNA during prophase I of meiosis.