Chapter 2 & 3 Flashcards
(18 cards)
Law of Segregation:
Two alleles for each trait segregate during gamete formation, then unite at random at fertilization.
Phenotype
Observable characteristic of an organism
Genotype
Pair of alleles present in an individual
Homozygous
Two alleles of trait are the same (YY or yy)
Heterozygous
Two alleles of trait are different (Yy)
Recombinant type
Offspring or cells that have a different combination of genes or traits than their parents or the original cell
Incomplete dominance
F1 hybrids express an intermediate phenotype
Codominance
F1 hyrids express phenotype of both parents equally
Mutation
Alleles arise spontaneously in nature due to chance alterations in genetic material
Wild-type
Allele whose frequency is more than 1%
Mutant
Allele whose frequency is less than 1%
Monomorphic
Gene with only one wild-type allele
Polymorphic
Gene with more than one wild-type allele
Polygenic
Traits or conditions influenced by multiple genes, rather than a single gene
Pleiotropy
One gene can contribute to multiple traits
Incomplete penetrance
Fewer than 100% of individuals with the same genotype express a specific phenotype
(not all individuals with a particular genotype (a gene variant) exhibit the associated phenotype (trait))
Epistasis
The action of an allele on one gene hides traits normally caused by alleles at another gene.
(genetic phenomenon where the effect of one gene is influenced by the presence of other genes)
Complementation test
Reveal whether a particular phenotype arises from mutations in the same or separate genes
