Natural selection can alter the frequency of distribution allele and heritable trait in different following way

A- Accumulation of those mutation that increase fitness of population in changing environment

B- Check accumulation of mutation that lower the fitness of species in unchanging environment

c- occur when population is subjected to divergent selection

#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: 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: 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: 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: 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: 1527

#Unit 4. Cell Communication and Cell Signaling

Following are the six fundamental properties of malignant tumors. Which of these properties are amenable to study in a cell culture model of cancer?

(I) self-sufficiency in growth signals

(II) insensitivity to antigrowth signals

(III) evasion of apoptosis

(IV) limitless replicative potential

(V) sustained angiogenesis

(VI) tissue invasion and metastasis