Mendelian Genetics Flashcards
Genes
Made up of DNA and are the basic units of heredity that produce specific traits in offspring
Alleles
Variant forms of the same genes
Dominant Allele
If the two alleles in a pair are both dominant, the dominant trait is expressed.
Recessive Allele
If the two alleles in a pair are both recessive, the recessive trait is expressed.
Principle of Dominance
Dominant alleles masks the effects of its recessive partner
Homozygous
Identical alleles for a trait
Heterozygous
Different alleles for a trait
Law of Segregation
Alleles occur in pairs and those paired alleles segregate during meiosis and each sperm or egg cell receives only one member of the pair of alleles
Genotype
Genetic makeup for a specific trait
Phenotype
Physical traits of an organism
Monohybrid Cross
A single trait cross
Dihybrid Cross
A two trait cross
If two heterozygous individuals are the parents, then what is the phenotypic ratio of the phylogeny (offspring)?
9:3:3:1
Law of Independent Assortment
Alleles for different traits separate independently of one another during gamete formation
Probability in genetics is…
The number of possible chances of an event occurring divided by the number of possible combinations. It is helpful in explaining the frequency of genotypes and phenotypes in offspring.
Rule of Independent Events
Each event is considered individually so past occurrences have no impact on its outcome
Product Rule
Probability of independent events occurring simultaneously is equal to the product of these events occurring separately
Pedigree
A pedigree is like a detailed family tree that is used to determine the probability of a particular allele appearing in an offspring.
Test cross (monohybrid)
Determines if the genotype of an individual is pure bred dominant or hybrid. Crossing of the unknown genotype showing a dominant trait with a homozygous recessive genotype.
Test cross (dihybrid)
Determines if the genotype of an individual is pure bred dominant or hybrid. Crossing the unknown genotype with a homozygous recessive genotype.
Incomplete Dominance
Heterozygous form results in a phenotype which is intermediate between the two pure forms, partially expressing both alleles
Codominance
The heterozygous form shows complete expression of both alleles involved. An exmaple is blood type
Genome
A set of all of the genes a species has on its chromosomes
