Campbell Biology (10th Edition) - Chapter 13: Meiosis and Sexual Life Cycles_Vocabulary

Haploid Cell

A cell containing only one set of chromosomes (n)

Diplod Cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent

Recombinant Chromosomes

A chromosome created when crossing over combines DNA from two parents into a single chromosome

Sex Chromosomes

A chromosome responsible for determining the sex of an individual

Autosome

A chromosome that is not directly involved in determining sex; not a sex chromosome

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses)

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape

Gamete

A haploid reproductive cell, such as an egg or sperm; unite during sexual reproduction to produce a diploid zygote

Alternation of Generations

A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae

Clone

A lineage of genetically identical individuals or cells; an individual that is genetically identical to another individual

Meiosis

A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. Results in cells with half the number of chromosomes sets as the original cell

Homologous Chromosomes (homologs)

A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One is inherited from the organism's father, the other from the mother.

Locus

A specific place along the length of a chromosome where a given gene is located

Sexual Reproduction

A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from both parents via the gametes

Synaptonemal Complex

A zipper-like structure composed of proteins, which connects two homologous chromosomes tightly along their lengths

Somatic Cells

Any cell in a multicellular organism except a sperm or egg or their precursors

Variation

Differences between members of the same species

Chiasma

The X-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids. Become visible after synapsis ends, with the two homologs remaining remaining associated due to sister chromatid cohesion

Zygote

The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg

Meiosis I

The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell

Asexual Reproduction

The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts); in most cases, results in offspring that are genetically identical to the parent

Synapsis

The pairing and physical connection of duplicated homologous chromosomes during prophase I of meiosis

Crossing Over

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

Genetics

The scientific study of heredity and hereditary variation

Meiosis II

The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell

Heredity

The transmission of traits from one generation to the next

Fertilization

The union of haploid gametes to produce a diploid zygote