Chapter 16: Sexual Reproduction and Chromosomal Variations

These flashcards cover key concepts related to sexual reproduction, life cycles, chromosome variations, and related disorders described in the lecture notes.

Sexual Reproduction

A process that involves the fertilization of two haploid gametes to create a diploid zygote.

Zygote

A diploid cell formed by the union of two haploid gametes.

Diploid dominant

A life cycle in which the multicellular organism is diploid and the gametes are haploid.

Haploid dominant

A life cycle in which the multicellular organism is haploid, and the zygote is the only diploid cell.

Alternation of generations

A life cycle strategy in which a multicellular diploid sporophyte generation alternates with a multicellular haploid gametophyte generation.

Meiosis

A type of cell division that produces haploid gametes from a diploid cell.

Nondisjunction

An error in cell division where chromosomes do not separate properly, leading to aneuploid gametes.

Aneuploidy

A condition with an abnormal number of chromosomes, resulting from nondisjunction.

Trisomy

A condition resulting in the presence of an extra chromosome, such as in Down syndrome (Trisomy 21).

Monosomy

A condition resulting in the absence of one chromosome from the normal diploid set.

Polyploidy

A condition where an organism has three or more sets of chromosomes.

Chromosomal mutations

Changes in chromosome structure including deletions, duplications, inversions, and translocations.

Sporophyte

The multicellular diploid phase in the alternation of generations that produces haploid spores.

Gametophyte

The multicellular haploid phase in the alternation of generations that produces gametes.

chromosome variation

Differences in the structure and number of chromosomes between individuals of the same species.

Human chromosome number

Humans have a normal diploid number of 46 chromosomes, arranged in 23 pairs.

Chromosomal abnormality

Anomalies in chromosome structure or number that can lead to various health issues.