61. Biology and genetics of populations. Phenotype, genotype and gene (allele) frequencies. Hardy-Weinberg Law. And 62. Hardy-Weinberg law. Factors affecting.

Question 1

Allele frequency: am measure of the relative frequency of an allele on a genetic locus in a population (show the genetic diversity of species or richness of it’s gene pool)

Answer 1

Allele frequency: am measure of the relative frequency of an allele on a genetic locus in a population (show the genetic diversity of species or richness of it’s gene pool)

Question 2

Genetic locus: specific location of a gene - DNA sequence, position on chromosome Population: set of individuals of the same species living in a given place at a given time that can interbreed to produce fertile offspring

Answer 2

Genetic locus: specific location of a gene - DNA sequence, position on chromosome Population: set of individuals of the same species living in a given place at a given time that can interbreed to produce fertile offspring

Question 3

Genetic diversity: number of genetic characteristics in genetic make up of species Gene pool: the stock of different genes in an interbreeding population Frequencies of alleles - shown in histogram

Answer 3

Genetic diversity: number of genetic characteristics in genetic make up of species Gene pool: the stock of different genes in an interbreeding population Frequencies of alleles - shown in histogram

Question 4

Forces that lead to evolution: ~ these shouldn’t occur for Hardy-Weinberg Natural selection: alleles for fitter organisms become more frequent
Sexual selection: alleles for more sexually attractive organisms become more frequent Mutation: new alleles occur due to “mistakes in DNA”

Answer 4

Forces that lead to evolution: ~ these shouldn’t occur for Hardy-Weinberg Natural selection: alleles for fitter organisms become more frequent
Sexual selection: alleles for more sexually attractive organisms become more frequent Mutation: new alleles occur due to “mistakes in DNA”

Question 5

Genetic drift: changes an allele frequency due to random chance (not natural selection) Gene flow: immigration, emigration - changes in allele frequency due to mixing with new genetically different populations

Answer 5

Genetic drift: changes an allele frequency due to random chance (not natural selection) Gene flow: immigration, emigration - changes in allele frequency due to mixing with new genetically different populations

Question 6

Homozygous: 2 copies of identical gene

Heterozygous: 2 different alleles of a gene

Answer 6

Homozygous: 2 copies of identical gene

Heterozygous: 2 different alleles of a gene

Question 7

Alleles: sequences that code for a gene Genotype: set of alleles it possesses Dominant alleles: always expressed

Recessive alleles: only expressed when they are paired with another recessive

Answer 7

Alleles: sequences that code for a gene Genotype: set of alleles it possesses Dominant alleles: always expressed

Recessive alleles: only expressed when they are paired with another recessive

Question 8

Hardy-Weinberg law:

the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. - frequencies will remain constant as they are in equilibrium

Answer 8

Hardy-Weinberg law:

the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. - frequencies will remain constant as they are in equilibrium

Question 9

Hardy-Weinberg Laws:

1. large population size - large enough that chance occurrences cannot significantly change allelic frequencies
2. no mutation - In order for allelic frequencies to remain constant, there must be no change in the number of copies of an allele due to mutation.
3. no immigration or emigration - Whenever an individual enters or exits a population, it takes copies of alleles with it, changing the overall frequency of those alleles in the population.
4. random mating - In order for all alleles to have an equal chance of being passed down to the next generation, mating within the population must be random. Non-random mating can give an advantage to certain alleles.
5. random reproductive success - the survival of offspring to reproductive age, or reproductive success, must also be random.

Answer 9

Hardy-Weinberg Laws:

1. large population size - large enough that chance occurrences cannot significantly change allelic frequencies
2. no mutation - In order for allelic frequencies to remain constant, there must be no change in the number of copies of an allele due to mutation.
3. no immigration or emigration - Whenever an individual enters or exits a population, it takes copies of alleles with it, changing the overall frequency of those alleles in the population.
4. random mating - In order for all alleles to have an equal chance of being passed down to the next generation, mating within the population must be random. Non-random mating can give an advantage to certain alleles.
5. random reproductive success - the survival of offspring to reproductive age, or reproductive success, must also be random.

Question 10

Equation: p + q = 1
p = frequency of the dominant allele q = frequency of the recessive allele

p2 + 2pq + q2 = 1

p2 = homozygous dominant alleles 2pq = heterozygous alleles
q2 = homozygous recessive alleles

Answer 10

Equation: p + q = 1
p = frequency of the dominant allele q = frequency of the recessive allele

p2 + 2pq + q2 = 1

p2 = homozygous dominant alleles 2pq = heterozygous alleles
q2 = homozygous recessive alleles

Question 11

Gene frequency: the proportion of a particular allele among all allele copies being considered. Percentage of all alleles at a given locus in a gene pool represented by a particular allele.

Answer 11

Gene frequency: the proportion of a particular allele among all allele copies being considered. Percentage of all alleles at a given locus in a gene pool represented by a particular allele.

Question 12

Genotype frequency: number of individuals with a given genotype by the total number of individuals of the population

Answer 12

Genotype frequency: number of individuals with a given genotype by the total number of individuals of the population

Question 13

Phenotype frequency: number of individuals with a given phenotype by the total number of individuals of the population

Answer 13

Phenotype frequency: number of individuals with a given phenotype by the total number of individuals of the population