Meiosis and Sexual Reproduction Flashcards

Flashcards covering the key concepts of Meiosis and Sexual Reproduction from Chapter 16.

Meiosis

The process by which haploid cells are produced from a diploid cell.

Diploid (2n)

A cell with two sets of chromosomes.

Haploid (n)

A cell with one set of chromosomes.

Gamete

A sperm or egg cell containing a single, haploid set of chromosomes.

Bivalent (tetrad)

The structure formed when homologous pairs of chromosomes associate along their length during Prophase I of Meiosis.

Synapsis

The process of forming a bivalent during Prophase I of Meiosis.

Crossing Over

The exchange of DNA segments between nonsister chromatids during Prophase I of Meiosis, increasing genetic variation.

Chiasma

X-shaped regions on homologous pairs where crossing over has occurred.

Aneuploidy

A condition in which offspring have an abnormal number of a particular chromosome.

Monosomic

A zygote with only one copy of a particular chromosome.

Trisomic

A zygote with three copies of a particular chromosome.

Down Syndrome (Trisomy 21)

An aneuploid condition resulting from three copies of chromosome 21.

Klinefelter Syndrome (XXY)

Aneuploidy condition in males resulting from an extra X chromosome.

Turner Syndrome (X0)

Monosomy X in females, the only known viable monosomy in humans.

Polyploidy

A condition in which an organism has more than two complete sets of chromosomes.

Deletion (chromosome)

A change in chromosome structure where a chromosomal segment is removed.

Duplication (chromosome)

A change in chromosome structure where a segment is repeated.

Inversion (chromosome)

A change in chromosome structure where the orientation of a segment within a chromosome is reversed.

Translocation (chromosome)

A change in chromosome structure where a segment moves from one chromosome to another.

Sexual Reproduction

A reproductive process involving the fusion of two haploid gametes to form a diploid zygote.

Zygote

A diploid cell formed by the fusion of two haploid gametes during fertilization.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate correctly during meiosis.