Abortion: induced expulsion of the embryo or fetus from uterus

Aneuploidy: Having an extra or less chromosome.

Autosome: Any chromosome of a type that is the same in males and females of the species.

Crossing over: At prophase I of meiosis, genetic recombination is the result.

Deletion: loss of a segment from a chromosome.

Disease: Outcome of infection when defenses aren't mobilized fast enough and a pathogen's activiti

double-blind study: Different investigators independently collect, then compare data

Duplication: Gene sequence repeated several to many hundreds or thousands of times.

Genetic abnormality: A rare or less common version of a heritable trait.

Genetic disorder: Any inherited condition that causes mild to severe medical problems

Genetic Recombination: Result of any process that puts new genetic information into a DNA molecule.

Homologous chromosomes: One of a pair of Chromosomes indentical in size, shape and gene sequenc, and that interact at meiosis.

In-Vitro Fertilization: Conception outside the body.

Independent assortment: Mendelian Theory, each pair of homologous chromosomes are sorted before shipment to gametes independently of how the other pairs were sorted.

Inversion: Part of a chromosome that became oriented in reverse, with no molecular loss

karyotype: Preparation of metaphase chromosomes sorted by length, centromere location, other defining features.

Mosaicism: Cells of same type express genes differently, so phenotypic differences emerge in same type of tissue.

Non-disjunction: Failure of sister chromatids to separate during meiosis or mitosis.

Polyploidy: Having three or more of each type of chromosome in the nucleus of a eukaryotic cell at interphase.

Reciprocal Cross: A paired cross. In the first cross, one parent displays the trait of interest. In the second, the other parent displays it.

Sex Chromosome: A chromosome with genes that affects sexual traits (XX females. XY males)

Syndrome: A set of symptoms that may not individually be a telling clue but collectively characterize a genetic disorder or disease.

Translocation: movement of a stretch of DNA to a new chromosomal location with no molecular loss.

X Chromosomes: Type of sex xhromosome, that becomes female.

Y Chromosomes: type of sex chromosome, that become male.

Biology Terms Vocabulary

Allele: molecular forms of a gene that are formed by the union and code for different versions of the same trait.

Codominance: In heterozygotes, pair of nonidentical alleles that specify different phenotypes.

Continuous Variation: in a population, a range of small differences in trait among its individuals.

Dihybrid Cross: A union between two F1 heterozygotes that are identical for two gene loci; the dihybrids are offspring of parents that bred true for different versions of two traits.

F1: The offspring of an initial genetic cross.

F2: The offspring of parents who are the first generation from a genetic cross.

Gene: Information for a heritable trait, passed from generation to generation.

Genotype: Genetic constitution of an individual.

Heterozygous: is when the pair of alleles are different; --->(Aa)

Homozygous Dominant: is when the pair of alleles are identical; example --> (AA)or (BB)

Homozygous Recessive: is when the pair of allels are recessive and are identical; example --> (aa) or (bb).

Hybrid Offspring: offspring having a pair of nonidentical alleles for a trait.

Incomplete Dominance: Condition in which one allele of a pair is not fully dominant.

Independent Assortment: Mendelian theory that when meiosis ends, each pair of homologous chromosomes are sorted before shipment to gametes independently of how the other pairs were sorted. Later modified to account for the disruptive effect of crossing over on linkages.

Monohybrid Cross: Union between two F1 heterozygotes that are identical for one gene locus.

Multiple Allele System: Three or more slightly different molecular forms of a gene that occur among individuals of a population.

Phenotype: Observable trait or traits of an individual that arise from gene interactions and gene-environment interactions.

Pleiotropy: Positive or negative effects on two or more traits owing to expression of alleles at a single gene locus.

Probability: is a way of expressing knowledge or belief that an event will occur or has occurred.

Punnett-square method: Construction of a diagram as a way to predict probable outcomes of a genetic cross.

Segregation: Mendelian theory. Sexually reproducing organisms inherit pairs of genes, those two genes of each pair are separated from each other at meiosis, and they end up in separate gametes.

Testcross: Experimental cross to determine whether an individual of unknown genotype that shows dominance for a trait is either homozygous dominant or heterozygous.

True-breeding lineage: a lineage in which only one version of a trait appears over the generations in all parents and their offspring.