G E N E T I C S
Chapter 11
Chapter 11
More info. on Genetics go to: http://www.dnaftb.org/dnaftb/
Genetics - The branch of biology that deals with heredity, especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms.
True-breeding - Term used to describe organisms that produce offspring identical to themselves if allowed to self-polinate.
Trait - Specific characteristic that varies from one individual to another.
Hybrid - The offspring of two animals or plants of different breeds, varieties, species, or genera, esp. as produced through human manipulation for specific genetic characteristics.
Gene - The basic physical unit of heredity; a linear sequence of nucleotides along a segment of DNA that provides the coded instructions for synthesis of RNA, which, when translated into protein, leads to the expression of hereditary character.
Allele - One of a number of different forms of a gene.
Segregation - Seperation of allele during gamete formation.
Gamete - Specialized cell involved in sexual reproduction.
Probability - likelihood that a particular event will occur.
Punnett Square - Diagram showing the gene combinations that might result from a genetic cross.
Homozygous - (Same) - Term used to refer to an organism that has to identical alleles for a particular trait (AA, ss, pp, RR, etc.)
Heterozygous - (Different) - Term used to refer to an organism that has two different alleles for the same trait (Aa, Ss, Pp, Rr, etc.)
Phenotype - (See) - Physical characteristics of an organism (Brown hair, Blue eyes, etc.)
Genotype - (Letter) - Genetic make up of an organism (Aa, AA, aa, SS, Ss, ss, PP, Pp, pp, etc.)
Homologous - Term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent.
Diploid - Term used to refer to a cell that contains both sets of homologous chromosomes.
Haploid - Term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of genes.
Meiosis - Process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.
Tetrad - Structure containing 4 chromatids that form during meiosis.
Crossing-Over - Process in which homologous chromosomes exchange portions of their chromatids during meiosis.
Gene Map - Diagram showing the relative locations of each known gene on a particular chromosome.
