Chapter 13: Meiosis and Sexual Life Cycles

Flashcards for key terms and concepts in meiosis and sexual life cycles.

Heredity

The transmission of traits from one generation to the next.

Genetics

The scientific study of heredity and variation.

Gametes

Reproductive cells (sperm and eggs) that pass genes to the next generation.

Karyotype

An ordered display of the pairs of chromosomes from a cell.

Homologous chromosomes

Chromosomes in a homologous pair that are the same length and shape and carry genes controlling the same inherited characters.

Diploid (2n)

A cell that has two sets of chromosomes. For humans, this number is 46.

Haploid (n)

A cell that contains a single set of chromosomes. For humans, this number is 23.

Zygote

The fertilized egg that has one set of chromosomes from each parent.

Meiosis

A type of cell division that reduces the number of chromosome sets from diploid to haploid.

Crossing over

The exchange of genetic material between nonsister chromatids during prophase I of meiosis.

Independent assortment

The random orientation of homologous chromosomes during metaphase I of meiosis.

Synapsis

The pairing of homologous chromosomes during prophase I of meiosis.

Chiasmata

X-shaped regions where crossing over occurs between homologous chromosomes.

Cohesins

Proteins that hold sister chromatids together.

Genetic variation

The differences in the genetic makeup of individuals in a population.

Natural selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring.