keywords:
Bookmark and Share



Front Back
Diploid
A cell having two chromosome sets or an individual organism having two chromosome sets in each of its cells.

Haploid
A cell having one chromosome set or an organism composed of such cells
Gene
The fundamental physical and functional unit of heredity, which carries information from one generation to the next; a segement of DNA composed of a transcribed region and a regulatory sequence that makes transcription possible.
Dominant
The phenotype shown by a heterozygote.
Recessive
The phenotype shown by a homozygote.
Allele
One of the different forms of a gene that can exist on a single locus.
Phenotype
1. The form taken by some character (or group of characters) in a specifid individual.

2. The detectable outward manifestations of a specific geneotype.
Genotype
The allelic composition of an individual or of a cell - either of the entire genome or, more commonly, of a certain gene or a set of genes.
P = Parental generation
The two strains or individual organisms that constitute the start of a genetic breeding experiment; their progeny constitute the F1 generation.
F1 = First filial generation
The first filial generation, produced by crossing two parental lines.
F2 = Second filial generation
The second filial generation, produced by selfing or intercrossing the F1 generation.
Cross
The deliberate mating of two parental types of organisms in genetic analysis.
Reciprocal cross
A breeding experiment designed to test the role of parental sex on a given inheritance pattern.
Gamete
A cell which contains one pair of chromosomes (as opposed to two pairs in somatic cells), used in sexual reproduction
Segregation
(Mendel's 1st Law)
The two members of a gene pair segregate from each other in meiosis; each gamete has an equal probability of obtaining either member of the gene pair.
Heterozygotes
An individual organism having a heterozygous gene pair.
Homozygotes
An individual organism having a homozygous gene pair.
Independant assortment
(Mendel's Second Law)
Unlinked or distantly linked segregating gene pairs assort independantly at meiosis
Testcross
A cross of an individual organism of unkown genotype or a heterozygote (or a multiple heterozygote) with a tester.
Punnett Square
A diagram that is used to predict an outcome of a particular cross or breeding experiment.
True breeding
The breeding of two organisms with a particular, inheritable phenotype produce only offspring with that (same) phenotype.
Homologous chromosomes
Chromosomes that pair with each other at meiosis or chromosomes in different species that have retained most of the same genes during their evolution from a common ancestor.
Sister chromatids
Two identical copies of a chromatid connected by a centromere
Pedigree
The lineage or geneological descent of an organism.
x of y cards