BIOL 3040 Lecture Notes - Lecture 1: Genotype Frequency, Allele Frequency, Genetic Drift

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emeraldraven654

22 Sep 2015

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7. 1 individual-level versus population-level thinking: describe how population-level thinking is an extrapolation of individual-level thinking and how it can lead to unexpected outcomes. Population level of thinking takes into account overall frequencies of alleles and phenotypes. The shift from individual level of thinking (prevalent in the study of genetics) to population level thinking (associate with ecology and evolution) is critical in understanding the process of evolutionary change. Example: a genotype that is dominant in individuals might not be dominant in a population of individuals because the frequency of the population that contains that trait. Looking at a gene with two alleles in a population, allele a1 is dominant and a2 is recessive. What is he frequency of the dominant phenotype: 25, 50, 75, don"t know. What is the frequency of this allele (a2: q): 0. 0001, 0. 01, 0. 00005, 0. 00015. 7. 3 natural selection (s: given certain survivorship statistics, calculate the fitness and selection coefficient.

Related Questions

Mathephobia is a dreaded (but hypothetical) recessive condition that causes students to go into convulsions whenever they see formulas in biology class. D is the normal allele, d is the mathephobia allele.

DD and Dd individuals are normal

dd individuals are Mathephobic

In a class of 100 biology students, 32 had convulsions during their first population genetics lecture. Assume that students are a representative sample of a population at Hardy-Weinberg equilibrium.

a) What is the frequency of the mathephobia (d) allele in this population?

b) How many students in this class are homozygous dominant (DD) and heterozygous (Dd) for this condition?

The trauma induced by a second genetics lecture caused 75% of the students with the mathephobia to spontaneously combust and disappear.

c) What is the frequency of each allele in the surviving population of genetics students?

d) What are the frequencies of each genotype and phenotype?

mauverhinoceros362

Problem B: Prairie Dog Population Genetics
A relatively stable population of Black-footed Prairie Dogs (70,000 individuals) lives in a national park in
Saskatchewan, Canada. These creatures have various tones of brown fur, but may have brown or auburn tails.
Furthermore, tails may be of solid color (brown or auburn) or be tipped with white or black fur. Three alleles for
tail coloration exist in this population. These alleles include:

Allele	Trait	Notes on Phenotype and Relationship to other Alleles
T	White Tip	Tail has white fur at tip. Completely dominant over t; codominant with T*
t	Black tip	Tail has black fur at tip. Codominant with T*; recessive to T
T*	Auburn tail	Background tail color is auburn when T* is present. Codominant with T or t

The frequency of the (T) allele in this population is 0.28, and the frequency of the (t) is 0.4.
Answer each of the following. Show all of your work/calculations. Cite your rationale if appropriate.

1. List and describe all the possible genotypes and their respective phenotypes for this gene system in the
population.

2. Using the Hardy-Weinberg theorem, calculate the probable frequency of animals with the following
phenotypes in this population:
â¢ White tipped tails
â¢ Black tipped auburn tails

3. What is the expected combined frequency of individuals carrying the TT, TT* and Tt genotypes in this
population?

4. How many (number, not percentage) of the prairie dogs would you expect to have black tipped, auburn
tails? Explain.

5. In a different population of 10,000 prairie dogs (South Dakota, USA), only the T and t alleles are found. If
this group included only 400 animals with black tipped, brown tails, what is the probable number (not
frequency) of individuals that are homozygous dominant (TT) in this herd?

aquamarinepug18

You begin work on the genetics of shell banding patterns in a snail. A test cross indicates that mottling is controlled by two alleles (M and m) at a single locus. Individuals carrying the M allele have mottled shells, while mm snails have no mottling. You sample a population and determine that the frequency of m in the population is 0.6. Assume that the population is at HWE when answering the following questions: (i) What is the frequency of the M allele in the population? (ii) What are the expected genotype frequencies in the next generation? (iii) What are the expected frequencies of the mottled and non-mottled phenotypes in the next generation? (iv) How should the frequency of the M allele change through time

ultramarinemanatee826

BIOL 3040 Lecture Notes - Lecture 1: Genotype Frequency, Allele Frequency, Genetic Drift

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