GN 311 terms 1

the probability of any 2 or more mutually exclusive events occurring is calculated by adding the probabilities of the individual events

one of 2 or more alternate forms of a gene

Procedure used for prenatal genetic testing to obtain a sample of amniotic fluid from a pregnant woman. A long sterile needle is inserted through the abdominal wall into the amniotic sac to obtain the fluid

stage of mitosis in which chromatids separate and move chromosomes the spindle poles

stage of meiosis I. In anaphase II, chromatids separate and move toward the spindle poles

stage of meiosis II. In anaphase II, chromatids separate and move toward the spindle poles

increasing severity or earlier age of onset of a genetic trait in succeeding generations. For example, symptoms of a genetic disease may become more sever as the trait is passed from generation to generation

one of the 3 primary divisions of life. It consists of unicellular organisms with prokaryotic cells

Chromosome that is the same in males and females; nonsex chromosome

Cross between an F1 individual and one of the parental (P) genotypes

Condensed, darkly staining structure that is found in most cells of female placental mammals and is an inactivated X chromosome

Refers to a synapsed pair of homologous chromosomes

Early concept of heredity proposing that offspring possess a mixture of the traits from both parents

Stages through which a cell passes from one cell division to the next

All life is composed of cells, that cells arise only from other cells, and the cell is the fundamental unit of structure and function in living organisms

Another name for map unit

A key transition point at which progression to the next stage in the cell cycle is regulated

Material found in the eukaryotic nucleus; consists of DNA and proteins

States that genes are located on the chromosome

Type of allelic interaction in which the heterozygote simultaneously expresses traits of both homozygotes

Ratio of observed DCO to expected DCOs

Molecule that holds the 2 sister chromatids of a chromosome together. The breakdown of it at the centromeres enables the chromatids to separate in anaphase of mitosis and anaphase II of meiosis

2 different mutations in the heterozygous condition are exhibited as the wild-type phenotype; indicates that the mutations are at different loci

Test designed to determine whether 2 diff mutations are at the same locus (allelic) or at diff loci (nonallelic). 2 individuals that are homozygous for the 2 independently derived mutations are crossed, producing F1 progeny that are heterozygous for the mutations. If the mutations are at the same locus, the F1 will have a mutant phenotype. If the mutations are at diff loci, the F1 will have a wild-type phenotype

Principle of heredity discovered by Mendel stating that, when 2 diff alleles are present in a genotype, only 1 allele may be expressed in the phenotype. The dominant allele is the allele that is expressed, and the recessive allele is not.

% of twin pairs in which both twins have a particular trait

Mating btw related individuals (double line)

Displays a large # of possible phenotypes that are not easily distinguished (height)

Arrangement in which 2 or more wild-type genes are on 1 chromosome and their mutant alleles are on the homologous chromosome

Exchange of genetic material btw homologous but nonsister chromatids

Process by which the cytoplasm of a cell divides

Inheritance of characteristics encoded by genes located in the cytoplasm. B/c the cytoplasm is usually contributed entirely by only 1 parent, most cytoplasmically inherited characteristics are inherited from a single parent

A cross btw 2 individuals that differ in 2 characteristics--more specifically, a cross btw individuals that are homo for diff alleles at the 2 loci (AABBxaabb); also refers to cross btw hetero at 2 loci (AaBbxAaBb)

Belongs to a species whose members have either male or female reproductive structures

Processing 2 sets of chromosomes (2 genomes)

Exhibits only a few, easily distinguished phenotypes. Ex. a seed shape in which seeds are either round or wrinkled

Nonidentical twins that arise when 2 diff eggs are fertilized by 2 diff sperm (fraternal twins)

Refers to an allele or a phenotype that is expressed in homo (AA) and in hetero (Aa)

Equalization in males and females of the amt of protein produced by X-linked genes. In placental mammals, it is accomplished by the random inactivation of 1 X chromosome in the cells of females

Phenomena due to alterations to DNA that do not include changes in the base sequence; often affect the way in which the DNA sequences are expressed. Such alterations are often stable and heritable in the sense that they are passed from one cell to another

Type of gene interaction in which a gene at one locus masks or suppresses the effects of a gene at a diff locus

Masks or suppresses the effect of a gene at a diff locus

1 of the 2 primary divisions of life. It consists of unicellular organisms w/ prokaryotic cells and include most of the common bacteria

Organism w/ a complex cell structure including a nuclear envelope and membrane-bounded organelles. 1 of the 3 primary divisions of life, they include unicellular and multicellular forms

Degree to which a trait is expressed

Offspring of the initial parents (P) in a genetic cross

Offspring of the F1 generation in a genetic cross; the 3rd generation of a genetic cross

Fusion of gametes, or sex cells, to form a zygote

Genetic factor that helps determine a trait; often defined at the molecular level as a DNA sequence that is transcribed into an RNA molecule

Interactions btw genes at diff loci that affect the same characteristic

Educational process that attempts to help patients and family members deal w/ all aspects of a genetic condition

Map of the relative distances btw genetic loci, markers, or other chromosome regions determined by rates of recombination; measured in % recombination or map units

Determines the phenotype of an offspring. an offspring inherits genes for the characteristics from both parents, but the offspring's phenotype is determined not by its own genotype but by the nuclear genotype of its mother

Sex-determining system in which sexual phenotype is controlled by a balance btw genes on the X chromosome and genes on the autosomes

Sex determination in which the sexual phenotype is specified by genes at 1 or more loci, but there are no obvious diff in the chromosomes of males and females

Complete set of genetic instructions for an organism

Differential expression of a gene that depends on the sex of the parent that transmitted the gene. If the gene is inherited from the father, its expression is diff from that if it is inherited from the mother

The set of genes possessed by an individual organism

Cells in the reproductive organs carry a complete set of genetic info

Statistical test used to evaluate how well a set of obs values fit the exp values. The probability associated w/ a calculated chi-square value is the probability that the diff btw the obs and exp values may be due to chance

Possessing a single set of chromosomes (1 genome)

Possession of a single allele at a locus. Males of organisms w/ XX-XY sex determination are __ for X-linked loci, b/c their cells possess a single X chromosome

Condition in which an individual organism possesses both male and female reproductive structures. True __ produce both male and female gametes

The sex (male or female) that produces 2 types of gametes wrt sex chromosomes. Ex. in the XX-XY sex-determining system, the male produces both X-bearing and Y-bearing gametes

An individual organism that possessed 2 diff alleles at a locus

Low-molecular-weight protein found in eukaryotes that complexes w/ DNA to form chromosomes

The sex (male or female) that produces gametes that are all alike w/ regard to sex chromosomes. Ex. in the XX-XY sex determining system, the female produces only X-bearing gametes

2 chromosomes that are alike in structure and size and that carry genetic info for the same set of hereditary characteristics. 1 chromosome of it is inherited from the male and other from the female parent

An individual organism that possesses 2 identical alleles at a locus

Gene that is masked or suppressed by the action of a gene at a diff locus

the phenotype of a heterozygote that is intermediate btw the phenotypes of the 2 homos

Refers to a genotype that does not always express the expected phenotype. Some individuals possess the genotype for a trait but do not express the phenotype

Early notion of inheritance proposing that acquired traits are passed to descendents

Recombination among genes on diff chromosomes

Degree to which 1 crossover interferes w/ additional crossovers

Period between meiosis I and meiosis II

Period in the cell cycle between the cell divisions. The cell grows, develops, and prepares for cell division

Recombination among genes located on the same chromosome

Human condition in which cells contain 1 or more Y chromosomes along w/ multiple X chromosomes (most commonly XXY but may also be XXXY, XXXXY, or XXYY). They are male in appearance but freq possess small testes, some breast enlargement, and reduced facial and pubic hair; often taller than normal and sterile; normal intelligence

Causes the death of an individual organism, often early in development, and so the organism does not appear in the progeny of a genetic cross. Recessive __ kill individual organisms that are homo for the allele; dominant __ kill both hetero and homo

Genes located together on the same chromosome

Genes located on the same chromosome

Position on a chromosome where a specific gene is locatec

In 1961, this proposes that 1 X chromosome in each female cell becomes inactivated (a Barr body) and suggests that which X becomes inactivated is random and varies from cell to cell

Period of active cell division; includes mitosis (nuclear division) and cytokinesis (cytoplasmic division)

Unit of measure for distances on a genetic map; 1 __=1% recomb

Relates recombination frequencies to actual physical distances between genes

Process in which chromosomes of a eukaryotic cell divide to give rise to haploid reproductive cells. Consists of 2 divisions

Stage of mitosis where chromosome align in the center of the cell

Stage of meiosis I where homo pairs of chromosomes align in the center of the cell

Stage of meiosis II where individual chromosomes align on the metaphase plate

Process by which the nucleus of a eukaryotic cell divides

An organism that is widely used in genetic studies b/c it has characteristics, such as short generation time and large # of progeny, that make it well suited to genetic analysis

Study of the chemical nature of genetic info and how it is encoded, replicated, and expressed

Individual organism that has both male and female reproductive structures

A cross btw 2 individuals that differ in a single characteristic-homo for diff alleles at the same locus (AAxaa); or that are both hetero for 2 alleles at a single locus (AaxAa)

Identical twins that arise when a single egg fertilized by a single sperm splits into 2 separate embryos

100 map units

Determined by multiple genes and environmental factors

Presence in a group of individuals of more than 2 alleles at a locus. Although, for the group, the locus has more than 2 alleles, each member of the group has only 2 of the possible alleles

States that the probability of 2 or more independent events occurring together is calculated by multiplying the probabilities of each of the individual events

Failure of homo chromosomes or sister chromatids to separate in meiosis or mitosis

Contains only the original combinations of genes present in the parents

Possesses the original combination of traits possessed by the parents

Range of phenotypes produced by a particular genotype in diff environmental conditions

Space in eukaryotic cells that is enclosed by the nuclear envelope and contains the chromosomes

Egg production in animals

Site where DNA synthesis is initiated

First set of parents in a genetic cross

Early concept of heredity proposing that particles carry genetic info from diff parts of the body to the reproductive organs

Pictorial representation of a family history outlining the inheritance of 1 or more traits or diseases

% of individuals w/ a particular genotype that express the phenotype expected of that genotype

Phenotype that is produced by environmental effects and is the same as the phenotype produced by a genotype

Appearance or manifestation of a characteristic

Map of physical distances btw loci, genetic markers, or other chromosome segments; measured in base pairs

A single genotype influences multiple phenotypes

Encoded by genes at many loci

Study of the genetic composition of populations (groups of members of the same species) and how a population's collective group of genes changes w/ the passage of time

Early concept of inheritance proposing that a mini adult (homunculus) resides in either the egg or the sperm and increases in size during development, w/ all traits being inherited from the parent that contributes the homunculus

Spermatogonium that has entered prophase I

Important principle of heredity that states that genes encoding diff characteristics (genes at diff loci) separate independently; applies only to genes located on diff chromosomes or to genes far apart on the same chromosome

Important principle of heredity that states that each diploid individual possesses 2 alleles at a locus and that these 2 alleles separate when gametes are formed, 1 allele going into each gamete

Likelihood of a particular event occurring; the # of times a particular event occurs/the # of all possible outcomes

A person w/ a trait or disease for whom a pedigree is constructed

Unicellular organism w/ a simple cell structure. Include eubacteria and archaea

Stage of mitosis where the nuclear membrane breaks down and the spindle microtubules attach to the chromosomes

Stage of mitosis; chromosomes contract and become more visible, the cytoskeleton breaks down, and the mitotic spindle begins to form

Stage of meiosis I: chromosomes condense and pair, CROSSING OVER takes place, the nuclear membrane breaks down, and the spindle form

Stage of meiosis II after interkinesis: chromosomes condense, the nuclear membrane breaks down, and the spindle forms

Small region of the X and Y chromosomes that contain homo gene sequences

Shorthand method of determining the outcome of a genetic cross. The alleles in the gametes are combined to form genotypes of offspring

Continuous characteristic; displays a large # of possible phenotypes, which must be described by a quantitative measurement

Refers to an allele or phenotype that is expressed only when homo (not expressed in hetero)

Crosses in which the phenotypes of the male and female parents are reversed. Ex. a tall male is crossed w/ short female, and in other cross short male cross w/ tall female

Possesses new combinations of genes

Possesses new combinations of traits formed from recombinant gametes

Sorting of alleles into new combinations

Proportion of recombinant progeny produced in a cross

Arrangement in which each chromosome contains 1 wild-type (dominant) gene and 1 mutant (recessive) gene. "repulsion"

Product of meiosis I in male

Phenomenon in which the sex of an individual organism changes in the course of its lifetime; the organism is male at one age or developmental stage and female at a diff age or stage

Male or female

Chromosomes that differ morphologically or in number in males and females

Specification of sex; __ mechanisms include chromosomal, genic, and environmental __ systems

On the Y chromosome, a gene that triggers male development (aka testis-determining factor (TDF) gene

Encoded by autosomal genes that are more readily expressed in one sex. Ex, an autosomal dominant gene may have higher penetrance in males than in females or an autosomal gene may be dominant in males but recessive in females

Encoded by autosomal genes and expressed in only one sex. Both males and females carry genes for __ but the characteristics appear in only one of the sexes

Characteristic determined by a gene or genes on sex chromosomes

2 copies of a chromosome that are held together at the centromere. Each __ consists of a single DNA molecule

Immediate product of meiosis II in spermatogenesis; matures to sperm

Sperm production in animals

Diploid cell in the testis; capable of undergoing meiosis to produce a sperm

Close pairing of homo chromosomes

Stable end of a chromosome

Stage of mitosis: the chromosomes arrive at the spindle poles, the nuclear membrane re-forms, and chromosomes relax and lenghten

Stage in meiosis: chromosomes arrive at spindle poles

Expressed only at certain temps

A cross btw an individual w/ an unknown genotype and an individual w/ the HOMO RECESSIVE genotype

The 4 products of meiosis; all 4 chromatids of a homo pair of chromosomes

Cross btw an individual HETERO at 3 loci and an individual HOMO for RECESSIVE alleles at those loci

Field of genetics that encompasses the basic principles of genetics and how traits are inherited

Human condition in which cells contain 3 X chromosomes. A person w/ __ has a female phenotype q/o distinctive features other than a tendency to be tall and thin; a few such women are sterile, but many menstruate reg and are fertile

Human condition in which cells contain a single X chromosome and no Y chromosome (XO). They are female in appearance but do not undergo puberty and have poorly developed female secondary sex characteristics; most are sterile but have normal intelligence

Cross btw an individual HETERO at 2 loci and an individual HOMO for RECESSIVE alleles at those loci

Procedure for visualizing the fetus. High-freq sound is beamed into the uterus. Sound waves that encounter dense tissue bounce back and are transformed into a pic of the fetus

The trait or allele that is most commonly found in natural (wild) populations

Characteristic determined by a gene or genes on the X chromosome

Ratio of the # X chromosomes to the # of haploid autosomal sets of chromosomes; determines sex in fruit flies

Characteristic determined by a gene or genes on the Y chromosome