Lecture Quiz 3

A hurricane comes through and wipes out 90% of a population of the elusive striped lizard: Lizards buckeye. The remaining members of the population survived due to chance alone. If the allele frequency in the population changed as a result of this hurricane, which of the following can explain how?

genetic drift

Hardy Weinberg equation

p^2 + 2pq + q^2 = 1

In one species of forest mice, the dominant allele (A/-) for their fur color can be recognized with the distinctive brown tone, while recessive homozygous mice (a/a) have a light gray fur. If 62 mice in one population were trapped and labeled, and only 14 of them were gray, what would be the expected frequency of alleles A and a in this population, assuming that it is in Hardy-Weinberg equilibrium?

0.525 and 0.475

Hardy Weinberg 5 assumptions

1. random mating 2. no natural selection 3. no genetic drift 4. no gene flow 5. no mutation

In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4?

B4

Mutation and Natural Selection are both random mechanisms of evolution.

False

Which of the following statements about species, as defined by the biological species concept, is (are) correct?I. Biological species are defined by reproductive isolation.II. Biological species are the model used for grouping extinct forms of life.III. All members of a species can potentially interbreed.

I and III

Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. What keeps the two populations separate?

Habitat isolation

Which of the following is not one of the assumptions of Hardy-Weinberg equilibrium?

Individuals have differential reproductive success.

What distinguishes a morphospecies?

It has distinctive characteristics, such as size, shape, or coloration

What is natural selection selecting for in the example with the strainer?

MRSA, aka Methicillin-resistant Staphalococcus aureus

What would result in the greatest selection pressure for antibiotic resistance?

Not taking the full prescribed course of antibiotics

Many songbirds breed in North America in the spring and summer and then migrate to Central and South America in the fall. They spend the winter in these warmer areas, where they feed and prepare for the spring migration north and another breeding season. Two hypothetical species of sparrow, A and B, over winter together in mixed flocks in Costa Rica. In spring, species A goes to the east coast of North America, and species B goes to the west coast. What can you say about the isolating mechanisms of these two species?

Their winter habitat has no bearing on their degree of reproductive isolation.

In the following figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest.Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp?

They have been geographically isolated from each other for a longer time.

Which of the following statements is/are true? NOTE: You may select as many true answers as you want.

a If you take too many antibiotics your body can build up resistance to antibiotics b Antibiotics are equally effective against bacterial and viral infections c Antibiotics may kill off good bacteria in your body leaving you more susceptible to future infections d If you are feeling very ill and over the counter medications don't make you feel better you will most likely need antibiotics to treat your infection e I am concerned that I will be affected by antibiotic resistance in my lifetime Answer: c,e

Which of these statements is true for a highly inbred population, if there are no other violations of Hardy-Weinberg equilibrium?

a Frequency of homozygous individuals increases, yet frequency of alleles does not change. b Frequency of heterozygotes increases, and frequency of alleles changes. c Frequency of homozygous individuals decreases, yet frequency of alleles does not change. d None of the above are correct. Answer: a

Select true or false to indicate which of the following groups could be identified using the Biological Species Concept:

lizard species living today - true sunflower species living today - true extinct dinosaurs - false bacteria living today - false

Researchers discovered that a new strain of bacteria that causes tuberculosis (M. tuberculosis) has a point mutation in the rpoB gene that codes for part of the RNA polymerase enzyme. This mutant form of RNA polymerase does not function as well as the more common form of RNA polymerase. A commonly used antibiotic called rifampin does not affect the mutant rpoB bacteria. A researcher mixes M. tuberculosis with and without the rpoB mutation and adds the bacteria to cell cultures. Half the cell cultures contain only standard nutrients, while the other half of the cell cultures contain rifampin and the standard nutrients. After many cell generations, the researcher finds that ____.

very few M. tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation, but almost all of the M. tuberculosis in the cell cultures with rifampin carry the rpoB mutation