Vocabulary of Concepts of Ch.12: Human Genetics.

Abortion	Premature expulsion of the fetus from uterus.
Aneuploidy	Having one extra or one less chromosome relative to the parental chromosome number.
Autosome	Any chromosome of a type that is the same in males and females of the species.
Crossing Over	At prophase I of meiosis, an interaction in which non-sister chromatids of a pair of homologous chromosomes break at corresponding sites and exchange segments; genetic recombination is the result.
Deletion	At cytological level, loss of a segment from a chromosome. At molecular level, loss of one to a few base pairs from a DNA molecule.
Disease	Outcome of infection when defenses aren't mobilized fast enough and a pathogen's activities interfere with normal body functions
Double-blind Study	Different investigators independently collect, then compare data.
Duplication	Gene sequence repeated several to many hundreds or thousands of times. Even normal chromosomes have such sequences.
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 (e.g., by crossing over).
Homologous Chromosome	Of cells with a diploid chromosome number, one of a pair of chromosomes identical in size, shape, and gene sequence, and that interact at meiosis. Nonidentical sex chromosomes (e.g., X and Y) also interact as homologues during meiosis.
In-Vitro Fertilization	Conception outside the body (''in glass'' petri dishes or test tubes).
Independent Assortment	Mendelian theory that by the end of meiosis, each pair of homologous chromosomes (and linked genes on each one) 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.
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.
Linkage Group	All genes on a chromosome.
Mosaicism	Cells of same type express genes differently, so phenotypic differences emerge in same type of tissue.
Non-disjunction	Failure of sister chromatids or a pair of homologous chromosomes to separate during meiosis or mitosis. Daughter cells end up with too many or too few chromosomes.
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 affect sexual traits.
Syndrome	A set of symptoms that characterize a genetic disorder or disease.
Translocation	Movement of a stretch of DNA to a new chromosomal location with no molecular loss.
X Chromosome	A type of sex chromosome; an XX mammalian embryo becomes female.
Y Chromosome	A type of sex chromosome; an XY pairing causes it to develop into a male.

Vocabulary of Concepts of Ch.11 Patterns of Inheritance

Allele: All molecular forms of the same gene.

Codominance: A relationship between two alleles of a gene.

Continous Variation: Small differences in a given trait among the individuals of a population.

Dihybrid Cross: An intercross between two F1 heterozygotes that are identical for two gene loci.

Epistasis: Interaction among the products of two or more gene pairs.
F1: The offspring of an initial genetic cross F2: The offspring of parents who are the first filial generation from a genetic cross. F2: The offspring of parents who are the first filial generation from a genetic cross.	Incomplete Dominance: Condition in which one allele of a pair is not fully dominant. Incomplete Dominance: Condition in which one allele of a pair is not fully dominant.
Gene: Units of information on heritable traits, passed from parents to offspring.	Homozygus Dominant: Has a pair of of dominant alleles. (AA) Homozygus Dominant: Has a pair of of dominant alleles. (AA)

Genotype: Genetic constitution of an individual. Genotype: Genetic constitution of an individual.	Monohybrid Cross:Intercross between two F1 heterozygotes that are identical for one gene locus. Monohybrid Cross:Intercross between two F1 heterozygotes that are identical for one gene locus.
Hybrid Offspring: offspring having a pair of nonidentical alleles.	Independent Assortment: Mendelian theory that, as meiosis ends, genes on pairs of homologus chromosomes have been sorted out for distribution into one gamete or another, independently of gene pairs on other chromosomes. Independent Assortment: Mendelian theory that, as meiosis ends, genes on pairs of homologus chromosomes have been sorted out for distribution into one gamete or another, independently of gene pairs on other chromosomes.

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

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

 

Probability: The chance that  each outcome of a given  event will occur is proportional to the number of ways the outcome  can be reached.

Probability: The chance that 

each outcome of a given 
event will occur is
proportional to the number
of ways the outcome 
can be reached.

Phenotype: Observable trait or traits of 

an individual that arisen from gene 

interactions and gene-environment

interactions.

True-Breeding Lineage: Of sexually
reproducing species,a lineage in which
only one version of a trait appears over the
generations in all parents and their offspring.

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

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

Punnet Square: Construction of a simple  diagram as a way to predict probable outcomes of a genetic cross.

Punnet Square: Construction of a simple 
diagram as a way to predict probable
outcomes of a genetic cross.

Pleiotropy: Positive or negative effects  on two or more traits owing to expression  of alleles at a single gene locus.Effects may  or may not emerge at the same time.

Pleiotropy: Positive or negative effects 
on two or more traits owing to expression 
of alleles at a single gene locus.Effects may 
or may not emerge at the same time.

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

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

Heterozygous:

Has a pair of nonidentical alleles. (Aa)

Homozygous Recessive:

Has a pair of recessive alleles. (aa)