In a large natural population of Mimulus guttatus, one leaf was sampled from each of a large number of plants. The leaves were crushed and subjected to gel electrophoresis. The gel was then stained for a specific enzyme, X. Six different banding patterns were observed, as shown in the accompanying diagram.

 Which one of the following conclusions is most appropriate based on the above observations?

A) There are three alleles of one locus and that the individuals with two bands are heterozygotes.

B) There are two alleles of one locus and that the individuals with two bands are heterozygotes

C) Population is present as hardy-Weinberg equilibrium

D) Population is not present as hardy-Weinberg equilibrium

#Question id: 1528

#Unit 4. Cell Communication and Cell Signaling

Mutation of p53 is described as a dominant-negative mutation. Which of the following statement is correct regarding to the mechanism by which this mutation causes the dominant-negative phenotype?

#Question id: 1529

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements are true regarding to gain-of-function and loss-of-function mutations with respect to cancer.

#Question id: 1530

#Unit 4. Cell Communication and Cell Signaling

What are the differences and similarities between the transforming genes of retroviruses and those of DNA tumor viruses?

#Question id: 1532

#Unit 4. Cell Communication and Cell Signaling

For a particular microarray assay (DNA chip), cDNA has been made from the mRNAs of a dozen patients' breast tumor biopsies. Which of the following types of evidence will researchers be looking for in order to determine if the cells are cancerous?

#Question id: 1533

#Unit 4. Cell Communication and Cell Signaling

Why might using retroviral vectors for gene therapy increase the patient's risk of developing cancer?

#Question id: 1534

#Unit 4. Cell Communication and Cell Signaling

Cadherin proteins help animal cells stick (adhere) to each other. Choose which statement about cadherin in cancer cells that are metastasizing (spreading) throughout a patient's body is most likely correct.