Meiosis and Sexual Life Cycles

A set of flashcards summarizing key vocabulary and concepts from a lecture on Meiosis and Sexual Life Cycles in Campbell Biology.

Heredity

The transmission of traits from one generation to the next.

Genes

Units of heredity made up of segments of DNA, passed to the next generation via gametes.

Gametes

Reproductive cells (sperm and eggs) that contain a single set of chromosomes.

Asexual Reproduction

A mode of reproduction where a single individual passes genes to offspring without the fusion of gametes.

Clone

A group of genetically identical individuals from the same parent.

Somatic Cells

Any cells in the body other than sperm and eggs; human somatic cells have 23 pairs of chromosomes.

Karyotype

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

Homologous Chromosomes

The two chromosomes in each pair that are the same length and shape and carry genes controlling the same inherited characters.

Diploid Cell

A cell that contains two sets of chromosomes (2n). For humans, this number is 46.

Haploid Cell

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

Fertilization

The union of gametes (the sperm and the egg) to form a zygote.

Meiosis

A type of cell division that reduces the number of chromosome sets from diploid to haploid, producing cells that differ genetically.

Crossing Over

The exchange of DNA segments between nonsister chromatids during prophase I of meiosis.

Independent Assortment

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

Zygote

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

Sister Chromatids

Identical copies of a chromosome connected by a centromere, formed after DNA replication.

Cohesin Proteins

Proteins responsible for holding sister chromatids together during cell division.

Tetrad

A group of four chromatids formed during synapsis in prophase I.

Chiasmata

X-shaped regions where crossing over has occurred during prophase I.

Cytokinesis

The division of the cytoplasm during cell division, resulting in separate daughter cells.