Chapter 6 Flashcards
(28 cards)
Codominance
A form of inheritance where both alleles in a heterozygous organism are fully expressed, resulting in a phenotype that shows both traits equally (e.g., AB blood type).
Dominant
An allele that expresses its trait in a heterozygous organism, masking the effect of a recessive allele.
Equilibrium
A stable state in which genetic variation does not change significantly over time unless influenced by external factors.
Frequency
The proportion or percentage of a particular allele, genotype, or phenotype within a population.
Gene pool
The total collection of all alleles present in a population.
p², 2pq, q² (Equilibrium Model Prediction)
Terms from the Hardy-Weinberg equation representing genotype frequencies in a population:
p²
frequency of the homozygous dominant genotype (AA)
2pq
frequency of the heterozygous genotype (Aa
q²
frequency of the homozygous recessive genotype (aa)
Incomplete dominance
A type of inheritance in which a heterozygous individual exhibits a phenotype that is an intermediate blend of the two parental traits (e.g., red + white flowers → pink flowers).
Nonrandom mating
A mating pattern where individuals choose partners based on specific traits rather than at random, leading to changes in allele frequencies.
p, q
Variables representing allele frequencies in a population:
p
frequency of the dominant allele (A)
q
frequency of the recessive allele (a,(Since p + q = 1, these values help calculate genotype frequencies in Hardy-Weinberg equilibrium.)
Random mating
A mating pattern in which individuals pair without regard to their genotypes or phenotypes, maintaining genetic variation in a population.
Dominant vs. Recessive –
Dominant alleles express their trait in both homozygous (AA) and heterozygous (Aa) forms.
Recessive alleles only express their trait when two copies are present (aa).
Sampling error
A statistical error that occurs when a sample is not representative of the whole population, leading to inaccurate predictions about genetic variation.
Statistically significant
A result that is unlikely to have occurred due to chance, often determined by a p-value in statistical testing.
Diploid
An organism or cell with two sets of chromosomes (2n), one from each parent
Evolution
The change in allele frequencies within a population over generations due to natural selection, genetic drift, mutation, and gene flow.
Father
A male parent who contributes genetic material through sperm cells.
Gene flow
The transfer of alleles between populations due to migration, which can introduce new genetic variation.
Mother
A female parent who contributes genetic material through egg cells.
Mutation
A change in DNA sequence that can introduce new alleles into a population, contributing to genetic variation.
