Genetics Flashcards
What is the P generation, F1 generation, and F2 generation?
P: true breeding parents (BB bb)
F1: hybrids (Bb)
F2: hybrid offspring (BB Bb)
What is the law of segregation?
Each individual has 2 allele factors for a gene, during meiosis the alleles factors separate during gamete formation, each gamete has 1 allele factors from each pair of factors, fertilization gives each new individual 2 alleles factors for each trait
How many alleles are needed for a dominant gene and a recessive gene to occur?
Dominant: 1 allele
Recessive: 2 alleles
What does homozygous mean?
Has the same two alleles (DD or dd)
What does heterozygous mean?
Has two different alleles (Dd)
What does phenotype mean?
The physical appearance
Genotype + environment = phenotype
What does genotype mean?
Their alleles, heterozygous or homozygous
What is a dihybrid cross?
Two generic traits (BP bp)
Ratio is 9:3:3:1
What is incomplete dominance?
When an intermediate phenotype occurs.
CRCR (red) x CWCW (white) = CRCW (pink)
Ratio is 1:2:1 for offspring
What is epistasis?
Expression of one gene influences or masks the expression of another gene affecting the phenotype
What is codominance?
Both alleles for a trait are fully expressed in a heterozygote. This means that neither allele is dominant or recessive, and the offspring shows both traits simultaneously.
What is required to satisfy the Hardy - Weinberg equilibrium?
No mutations, generic drift, gene flow/migration, selection, and has random mating.
What is genetic drift?
The change in the frequency of a gene variant (allele) in a population due to random chance and can be influenced by the environment. It can lead to the loss of genetic variation within a population, especially in small populations.
What is the bottleneck effect?
An event causes a large reduction in the population leading there to be a decrease in genetic diversity
