Chapter 1 Complete Exam Guide Practice Questions And Answers.

b. HIV-1 - correct answer Which type of virus is causing the HIV/AIDS epidemic in humans? a. SIVcpzANT b. HIV-1 c. SIVstm d. HIV-2 subtype A e. HIV-2 subtype B d. HIV is an RNA virus that parasitizes the immune system cells. - correct answer How does HIV cause AIDS? a. HIV only causes AIDS if the host is infected with multiple HIV-1 types b. HIV is an RNA virus which integrates into red blood cells and causes death c. HIV is a DNA virus that parasitizes the immune system cells. d. HIV is an RNA virus that parasitizes the immune system cells. b.Initially increases, then decreases, and then increases until the patient develops AIDS - correct answer Without treatment, viral load in a patient that is HIV positive... a. Initially decreases, then increases until the patient develops AIDS. b.Initially increases, then decreases, and then increases until the patient develops AIDS. c. Continues to decrease until the patient develops AIDS. d. Continues to increases until the patient develops AIDS. a. CD4 and CCR5 (a coreceptor) - correct answer HIV initiates replication by latching on to which two proteins? a. CD4 and CCR5 (a coreceptor) b. delta32 and CCR5 c. a coreceptor and an integrator d. TCR and CD4 e. CD4 and CCR32 (a coreceptor) c. AZT interrupts the enzyme that adds more nucleotides to DNA - correct answer How does AZT work? a. AZT helps reverse transcriptase add more thymidine to the proteins b. AZT prevents entry into host cells c. AZT interrupts the enzyme that adds more nucleotides to DNA d. AZT kills existing virions a. Virions inside a person can mutate to a form that does not allow reverse transcriptase to incorporate AZT into DNA strands - correct answer Which of the following can cause AZT to become less effective as a treatment for HIV infection? a. Virions inside a person can mutate to a form that does not allow reverse transcriptase to incorporate AZT into DNA strands b. AZT molecules eventually mutate into regular thymidine c. Virions inside a person can mutate to a form that allows reverse transcriptase to use AZT as an efficient DNA building block d. All of these are correct. a. Increase in the presence of AZT, because AZT imposes selection for resistant virions - correct answer AZT resistant virions will: a. Increase in the presence of AZT, because AZT imposes selection for resistant virions b. Decrease in the presence of AZT, because new mutations will produce AZT susceptible virions c. Increase if the AZT is removed from the patient's bloodstream d. Decrease in the presence of AZT, because if AZT is present, selection will favor virions with reverse transcriptase that can incorporate AZT True - correct answer T/F HAART cocktails destroy most but not all of the HIV virions in the host's body. b. RNA to DNA to mRNA to protein - correct answer HIV follows which flow of genetic information? a. protein to DNA to mRNA b. RNA to DNA to mRNA to protein c. RNA to mRNA to DNA to proteins d. DNA to RNA to mRNA to protein False - correct answer T/F Evidence suggests that HIV was likely introduced into humans only once. b. Trahan's virions were phylogenetically nested within Schmidt's patient's virions (e.g. paraphyly) - correct answer In the Schmidt case, phylogenetic results indicated that... a. Trahan was likely infected by a member of the community b. Trahan's virions were phylogenetically nested within Schmidt's patient's virions (e.g. paraphyly) c. There is no other explanation besides Schmidt infecting Trahan d. Schmidt's patient's virions were phylogenetically distributed among Trahan's virions (e.g. polyphyly). b. Might influence an organism's reproductive success and survivability. - correct answer If we want to understand why a particular trait is common in a particular population, we should study how that trait: a. Might influence an organism's heritability. b. Might influence an organism's reproductive success and survivability. c. Might influence an organism's immune response. d. Might influence an organism's ability to undergo cellular division.