Mendelian Genetics Vocabulary Flashcards (:

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Created By Daisy Olaya.For Mrs. Goldberg's End Of The Year Biology Project.6th Period.

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The different forms of a gene. Y and y are different alleles of the gene that determines seed color. Alleles occupy the same locus, or position, on chromosomes. 
A locus on any chromosome but a sex chromosome. Not sex-linked. 
Co-Dominant Alleles
Two different alleles at a locus are responsible for different phenotypes, and both alleles affect the phenotype of the heterozygote. 
Complete Linkage
Complete linkage describes the inheritance patterns for 2 genes on the same chromosome when the observed frequency for crossover between the loci is zero. 
Crossing Over
Exchange of genetic material between non-sister chromatids from homologous chromosome during prophase I of meiosis; results in new allele combinations
Organisms produce only one type of gamete; i.e. humans 
Cell with two of each kind of chromosome; is said to contain a diploid, or 2n, number of chromosomes
Dominant Trait
cell with two of each kind of chromosome; is said to contain a diploid, or 2n, number of chromosomes
haploid female sex cell produced by meiosis
One gene masks the expression of a different gene for a different trait. 
F1 Generation
Offspring of a cross between true breeding plants, homozygous for the trait of interest 
F2 Generation
Offspring of a cross involving the F1 generation.
fusion of male and female gametes 
male and female sex cells, sperm and eggs
Genetic Recombination
major source of genetic variation among organisms caused by re-assortment or crossing over during meiosis
branch of biology that studies heredity 
The genetic constitution of an organism with respect to a trait. 
cell with one of each kind of chromosome; is said to contain a haploid or n, number of chromosomes.
If there is only one copy of a gene for a particular trait In a diploid organism, the organism is hemizygous for the trait, and will display a recessive phenotype. X-linked genes in fly or human males are hemizygous. 
passing on of characteristics from parents to offspring
Differing alleles for a trait in an individual, such as Yy. 
Homologous Chromosomes
The pair of chromosomes in a diploid individual that have the same overall genetic content. One member of each homologous pair of chromosomes in inherited from each parent. 
Both alleles for a trait are the same in an individual. They can be homozygous dominant (YY), or homozygous recessive (yy). 
heterozygous; usually referring to the offspring of two true-breeding (homozygous) individuals differing in the traits of interest. 
Incomplete Dominance
Intermediate phenotype in F1, parental phenotypes reappear in F2. 
Lethal Alleles
Mutated genes that are capable of causing death. 
genes that are inherited together on the same chromosome. Three inheritance patterns are possible: non-linkage, Partial linkage, and complete linkage. 
type of cell division where one body cell produces for gametes, each containing half the number of chromosomes in a parent’s body.
Mendel's Law of Independent Assortment
Alleles of different genes are assorted independently of one another during the formation of gametes. 
Mendel's Law of Segregation
Alleles segregate from one another during the formation of gametes. 
Organisms produce both male and female gametes; i.e. garden pea.
Monohybrid Cross
Cross involving parents differing in only one trait. 
Change in the DNA sequence of a gene to some new, heritable form. Generally, but now always a recessive allele. 
failure of homologous chromosomes to separate properly during meiosis; results in gametes with too many or too few chromosomes
Non-linkage describes the inheritance patterns for 2 genes on the same chromosome, when the expected frequency for crossover between the loci is at least one. 
Partial Linkage
Partial linkage describes one of the inheritance patterns for 2 genes on the same chromosome, when the expected frequency for crossover between the loci is greater than zero but less than one.
The physical appearance of an organism with respect to a trait, i.e. yellow (Y) or green (y) seeds in garden peas.
A single gene determines more than one phenotype for an organism. 
Transfer of male pollen grains to the pistil of a flower
The condition in which an organism has extra sets of chromosomes
A number that describes how likely it is that an event will occur. 
Punnet Square
A chart that shows the possible combinations of alleles that result from a genetic cross. 
The offspring of many generations that have the same traits. 
Recessive Trait
The opposite of dominant. A trait that is preferentially masked. 
Reciprocal Cross
Using male and female gametes for two different traits, alternating the source of gametes. 
Sex Chromosomes
Sex determination is based on sex chromosomes  
A gene coded on a sex chromosome, such as the X-chromosome linked genes of flies and man. 
Sexual Reproduction
pattern of reproduction that involves the production of subsequent fusion of haploid cells.
haploid male sex cells produced by meiosis
Test Cross
Generally a cross involving a homozygous recessive individual.
characteristic that is inherited; can be either dominant or recessive
Homozygous for the true-breeding trait. 
Wild-Type Allele
The non-mutant form of a gene, encoding the normal genetic function. Generally, but not always a dominant allele. 
diploid cell formed when a sperm fertilizes an egg.