Terms Exam 1 Flashcards
Inheritance of X trait is dominant in male and recessive in female
Sex-influenced
Parents with normal vision produce normal visioned daughters but if the mother is a carrier, then half the sons will be color blind
Recessive sex-linked
Homozygosity for overo allele results in all foals suffering from aganglionosis of large intestine and die within a few days after birth
Lethal gene
3 consecutive base pairs on mRNA is a codon that specifies an amino acid. There are 64 codons in total and they code for 20 amino acids
Genetic code
Interaction between gene alleles resulting in a heterozygote superior to either homozygote for a particular trait
Overdominance
Death before puberty for an individual
Semi-lethal
The phenotypic effect of genes at one locus is dependent upon what alleles are present at another locus distance from the first locus
Epistasis
Expression of trait occurs only in one sex (Ex: milk or egg production)
Sex-limited
The existence of more than one grade of a trait
Variable expressivity
Having two identical alleles of given gene
Homozygote
Allele expressed in phenotype of heterozygote
Dominant
Alternative form of a gene
Allele
Observable characteristic
Phenotype
Cross between individuals both homozygous for two genes
dihybrid cross
Alleles of one gene separate into gametes randomly with respect to alleles of other genes
independent assortment
Reproductive cells containing one copy of each gene
Gametes
Heritable entity that determines characteristics
Gene
Separation of two alleles of a gene into different gametes
Segregation
Individual with two different alleles for same gene
Heterozygote
Offspring of P generation
F1
Proportion of individuals carrying particular variant of a gene that also expresses an associated phenotype
Penetrance
Cross individual of unknown genotype with homozygous recessive individual
Test cross
Doesn’t contribute to heterozygous genotype
Recessive
Description of how animal should look/behave
Breed standards
Alleles an individual has
Genotype
