BSC 114 - Ch. 13

Clone

(1) A lineage of genetically identical individuals or cells. (2) An individual that is genetically identical to another individual. (3) To make one or more genetic replicas of an individual or cell.

Haploid Cell

A cell containing only one set of chomosomes.

Diploid Cell

A cell containing two sets of chromosomes, one set inherited from each parent.

Recombinant Chromosome

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

Gene

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

Karyotype

A dislay of the chromosome pairs of a cell afrranged by size and shape.

Gamete

A haploidreproductive cell, such as an egg or sperm. They unite during sexual reproduction to produce a diploid zygote.

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. It results in cells with half the number of chromosome sets as the original cell.

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 the gametes of the two parents.

Homologous Chromosome

Apair of chromosomes of the same length, centromere posistion, and staining pattern that posseses genes from the same characters at corresponding loci. One homologous chromosome is inherited from the organism's father, the other from the mother. Also called homologs, or a homologous pair.

Variation

Differences between members of the same species.

Zygote

The diploid product of the union of haploid gametes in conception; 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, the offspring are genetically identical to the parent.

Life Cycle

The generation-to-generation sequence of stages in the reproductive history of an organism.

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