Genetics Flashcards
What is fitness?
Relative ability of an organism to survive and pass on genes
What is phenotype?
Set of observable characteristics resulting from an interaction of the genotype and environment
What is genotype?
Set of genes in our DNA responsible for traits
How is genotype frequency calculated?
No of people with certain genotype/total number in sample
How is allele frequency calculated?
No of times a certain allele is seen/total no of alleles
What is the Hardy-Weinberg equilibrium?
Allele frequencies remain constant from generation to generation
What assumptions underlie the Hardy-Weinberg principle?
Mutation can be ignored Migration is negligible Mating is random No selective pressure Population size is large Allele frequencies equal in the sexes
What is natural selection?
Gradual process by which biological traits become more or less common in a population due to their fitness
What is negative selection?
Reduces fitness and decreases in frequency
What is positive selection?
Increases fitness and increases in frequency
What is genetic drift?
Random fluctuation of allele frequency in a small population
What is the founder effect?
Reduction of genetic variation when a small subunit of a large population establish a new colony
What is the first law of Mendelian inheritance?
Law of segregation
During gamete formation, alleles segregate from each other so each gamete carries only one allele for the gene
What is the second law of Mendelian inheritance?
Law of independent assortment
Gametes for different traits can segregate independently during the formation of gametes
What is the third law of Mendelian inheritance?
Law of dominance
Some alleles are dominant while others are recessive
