PBIO EXAM 3

What effect does the environment have on an organism's phenotype?

Assume that you cross two true-breeding individuals that differ for a single trait to produce an F1 individual. You then cross two F1s to produce an F2 population. If one allele for this trait is dominant and the other recessive, how many different genotypic and phenotypic classes will you have in the F2 generation?

When a diploid (2n) nucleus undergoes mitosis, each new nucleus is:

Which statement is false?

When we say that two genes are linked, it means that...

Which of the following results in a violation of Mendel's 2nd law?

When visiting the Galapagos Islands, Darwin observed finches with a wide variety of beak sizes and shapes. How did he think these different forms got there

What does the term "dihybrid cross" refer to?

When does crossing over occur?

Which of the following is/are necessary for natural selection to cause evolutionary change?

Self-fertilizing plants pollinate themselves. Their offspring will, therefore:

Which of the following fits the definition of pleiotropy?

When a diploid nucleus undergoes meiosis each new nucleus is...

The following diagram displays a diploid cell represented by black and white X's of the same size. This diagram shows which phase?

https://drive.google.com/open?id=0B83mdiGU_rtRWDFrd1liN0w0WkU

In what order do the 4 phases of mitosis occur?

Consider two individuals of the same species. #1 is fully fertile but incapable of surviving to reproductive age. #2 is highly robust, such that it will live to a ripe old age, but it is completely sterile. Which one has higher fitness?

What prevents a cell that is not ready for division from entering mitosis?

Which process is random, natural selection or genetic drift?

In a cross between a heterozygous yellow-seeded plant (Yy; where Y= yellow and y=green) and a true-breeding green-seeded plant (yy), what phenotypic ratio would you expect to see in the offspring?

What affect does a population bottleneck have?

Distinguish between the terms gene and allele.

You cross a true-breeding red-flowered plant with a true-breeding white-flowered plant. All offspring are pink. Based on these results, what can you conclude?

Consider a population of plants that lives in a stable environment, and which produces seeds that are often eaten by squirrels (and thus destroyed). In order to maximize food content, squirrels preferentially gather and eat the largest seeds. What type of selection is this?

The term genetic drift refers to:

Assume that you are out on a field trip when you discover a plant of unknown genotype that exhibits the dominant form of a certain trait. Upon returning to campus, you ask around about how ti determine whether it was homozygous or heterozygous and you are advised to perform a test cross. What does this mean?

Which of the following statements about mutations is true?

Consider a hypothetical plant population consisting of 100 individuals. These individuals are segregating for two alleles (blue and white) at a gene controlling flower color. The blue allele is dominant to the white allele. Assume that you visited this population as it was just coming into flower and you observed 75 blue-flowered plants and 25 white-flowered plants. What is the frequency of heterozygotes in this population?

The following diagram displays a diploid cell represented by black and white X's of the same size. This diagram shows which phase?

https://drive.google.com/file/d/0B83mdiGU_rtRUzVCSFZsOFEwN0k/view?usp=sharing

You place a single, diploid cell in a Petri dish in your laboratory at the end of the day. When you come back the next morning, you find that there are now 8 cells, and they are all haploid. What processes could have led to this outcome?

(not 100% sure)

Consider a population of plants that exhibits variation in height. Further assume that a herbivore frequently passes through this population and eats all of the tall individuals before they have a chance to reproduce. Assuming that variation in plant height is ENTIRELY determined by differences in the micro-habitat in which a plant happens to be growing, what would you expect to happen to plant height in the next generation? ***

What happens in the S phase of interphase?

Sister chromatids are:

What would happen if sister chromatids didn't stay together during anaphase?

Animals have which type of life cycle?

Consider a population of plants that lives in a stable environment, and which produces seeds that are often eaten by birds (and thus destroyed). In order to maximize food content, the birds preferentially gather and eat the largest seeds. What type of selection is this?

Consider a hypothetical plant population consisting of 50 individuals. These individuals are segregating for two alleles (red and white) at a gene controlling flower color. Assume that the red allele is dominant over the white allele and that there are 30 red individuals and 20 white individuals. Given the above, what is the frequency of white homozygotes?

When a pair of homologous chromosomes aligns during metaphase I of meiosis, the male-derived chromosome (from Dad) and the female-derived chromosome (from Mom)...

You observe a single celled organism carefully for several generations and find that the cells that divide are always diploid. Sometimes the resulting daughter cells are diploid and sometimes they are haploid, but the haploid cells never seem to divide. This organism most likely has what kind of life cycle?

(ask about this one at review sesh)

Consider a population of plants that lives in a stable environment, and which produces seeds that are often eaten by birds (and thus destroyed). In order to maximize food content, the birds preferentially gather and eat the largest seeds. What type of selection is this?

Assume that you made the following cross: AAbb x aaBB to produce an F1 hybrid, and then crossed two F1s with each other to produce the F2 generation. If A is dominant to a and B is dominant to b and the genes are unlinked, what phenotypic ratio would you expect to observe in the F2 generation?

List the three phases of interphase in the correct order.

Genes being located near each other on a chromosome results in a violation of:

The following diagram displays a diploid cell represented by black and white X's of the same size. This diagram shows which phase?

https://drive.google.com/open?id=0B83mdiGU_rtRNlYyajF1cDQ3Z0U

Which of the following can cause natural selection?