1. Imagine a population of 100 snails in which the shell colour is controlled by two alleles: B (black) and b (yellow). () What is the total number of loci for shell colour gene in this population? In the snail population described above, 20 out of the snails are yellow (bb) and 80 are black (BB or Bb). Of the 80 black snails=, 30 are homozygous and 50 are heterozygous. How many loci for this gene are occupied by the B (i) allele? (ii) What is the frequency of the B allele? (iv) Assuming that sexual reproduction takes place with random mating, no gene flow and no selection, what will be the frequency of yellow snails in next generation of the population described above? (v) What will be the frequency of the b allele in the next generation of the snail population described below

5. In a population genetic study of a species of California wild oat, the following genotype frequencies were found for a trait (hairiness of the leaf sheath) which is controlled by a single locus: HH 0.571 Hh 0.071 hh 0.358 a)  What are the expected frequencies of these genotypes under Hardy-Weinberg? b)  Calculate F. c)  Briefly explain what the value in b) implies regarding heterozygosity and suggest what might be going on in this population to explain this result.

Imagine you have a VERY large garden consisting of thousands of red-flowered individuals (recessive homozygotes rr) and just a few dozen white-flowered plants (genotypes either RR or Rr) of the same species. The garden is isolated from all other flower populations. What do you think will happen to the frequency of the white-flowered plants in your garden from year to year, assuming that the two phenotypes survive and reproduce equally well, that flower color is inherited as a dominant trait, and that pollinating insects make no distinction in flower color? Why?

#12:  knowledge in genetics

4. A different population of lemmings have a third allele (i.e. a third version of the same gene) for hair colour, the blue allele. a) When pure-breeding red-haired lemmings were crossed with pure-breeding blue haired lemmings, the offspring all had purple hair. Using appropriate genetic diagrams, explain the above result. b) Predict the offspring and their ratios if the purple-haired lemmings were crossed with one another.

In fruit flies, long wings (L) are dominant over short wings (l). In a population of 45 fruit flies, 27 have LL genotypes, 13 have Ll genotypes,  and 5 have ll genotypes. Find the frequency of the following. Show all work and record your answer as a value between 0 and 1 rounded to two decimal places.a. long-winged fruit flies: b. short-winged fruit flies:

TABLE 1 Observed (O) versus expected (E) mc1r genotypes of black bears (Ursus americanus) by landmass in coastal British Columbia, Canada (2012-2017). Monte Carlo Exact Chi-square p-values reflect results from tests for departures from genotype frequencies expected under Hardy-Weinberg equilibrium. U-score p-values reflect tests for an excess or deficiency of heterozygosity at mc1r Landmass GG (white) E AG (black) E AA (black) E Chi² p U-score p Island Hawkesbury 0 0.00 0 0.00 24 24.00 Gribbell 1 1.13 7 6.75 10 10.12 1.00 0.74 Princess Royal 8 5.32 25 30.36 46 43.32 0.14 0.09 Roderick 0.01 1 0.98 21 21.01 1.00 1.00 Pooley 0 0.00 0 0.00 6 6.00 Yeo 0 0.00 0 0.00 5 5.00 Mainland West of Hawkesbury 0 0.03 2 1.94 East of Princess Royal 0 0.15 4 3.70 32 34 34.03 1.00 0.99 23 23.15 1.00 0.89 North of Roderick 0.02 1 0.96 11 11.02 1.00 1.00 Kynoch 0 0.00 0 0.00 15 15.00 Don Peninsula 0 0.01 1 0.98 21 21.01 1.00 1.00

Imagine that you have a test population of birds. You know from your previous research that there are two alleles (at the same locus) that govern feather type. Genotypes, and their associated phenotypes, are as follows: RR Red feathers Rr Red feathers rr white feathers Observing your population, you determine that you have 500 chickens with white feathers and 600 chickens with Red feathers. Based on Hardy–Weinberg expectations, how many of these are likely to be heterozygotes? (Show all  your work)

Scenario: plant species has flowers that can be red, pink, or white. Flower color is controlled by one gene with two alleles, A (p) and a (q). Red flowers are produced by AA homozygotes, pink flowers are produced by Aa heterozygotes and white flowers are produced by aa homozygotes. A recent survey of 100 of these plants found the following number of different flower colors: 75 plants with red flowers, 20 pink flowers, 5 white flowers.  Question: Among 500 plants,​​​​​​​ how many of the 'AA' genotype are expected under Hardy-Weinberg?

Snow geese (Chen caerulescens) come in two color types, white “snows” and “blues” with dark bodies. A single gene controls coloration, where the dark (“blue”) allele (D) is dominant. A population of 30,012 geese includes 9236 dark individuals. Genetic testing reveals that 7636 of the 9236 dark individuals are heterozygous (Dd). According to the Hardy-Weinberg equilibrium, what is the expected frequency of genotype Dd? Group of answer choices A.) 0.492 B.) 0.181 C.) 0.297 D.) 0.453