Concept explainers
Introduction: A type of RNA virus that inserts a copy of its genome into the DNA of an invaded host cell is called a retrovirus. Thereby, it changes the genome of the host cell. These viruses are composed only of RNA and not DNA. They possess specific enzymes that provide them the unique characteristics.
Answer to Problem 1U
Correct answer: b. Because host cells’ genomes do not contain a gene encoding an enzyme that can make DNA from RNA.
Explanation of Solution
Reason for the correct answer:
Retroviruses possess the reverse transcriptase enzyme. This is because the genome of the host cell does not possess a gene encoding an enzyme that could convert DNA from RNA. The reverse transcriptase enzyme converts RNA genome into DNA.
Option b. is given as “Because host cells’ genomes do not contain a gene encoding an enzyme that can make DNA from RNA”.
Hence, the correct answer is option b.
Reasons for the incorrect answers:
Option a. is given as “because host cells make DNA from RNA only in G2 of the cell cycle, and HIV infects only during G1 of the cell cycle”.
This is not an appropriate option that describes the function of reverse transcriptase enzyme in the retrovirus. Therefore, option a. is incorrect.
Option c. is given as “Because HIV deletes large parts of the host cell genome upon infection, and that means there is a chance that host cell reverse transcriptase will be deleted”.
The presence of reverse transcriptase in retroviruses facilitates reverse transcription of RNA into DNA. Therefore, option c. is incorrect.
Option d. is given as “Host cells cannot make RNA from DNA”.
This is not an appropriate option for the necessity of the presence of the reverse transcriptase enzyme in a retrovirus. Therefore, option d. is incorrect.
Hence, options a., c., and d. are incorrect.
Thus, the reason for the need of retroviruses to contain the reverse transcriptase enzyme is that it would facilitate the reverse transcription of RNA into DNA.
Want to see more full solutions like this?
Chapter 26 Solutions
<LCPO> BIOLOGY
- Compare the cloning efficiencies: SmaI vs. EcoRI.arrow_forwardHydrogen bonds play an important role in stabilizing and organizing biological macromolecules. Consider the four macromolecules discussed. Describe three examples where hydrogen bond formation affects the form or function of the macromolecule.arrow_forwardImagine you are a botanist. Below are characteristics of a never-before described plant species recently identified as part of the ‘All Taxa Biodiversity Inventory’ (ATBI). Field Notes: Specimen collected from shaded area along stream in South Cumberland State Park (Grundy County, TN). Laboratory Analysis: Body: Large leaves emerging from underground rhizome. Size: 63 cm Chromosomal Analysis: Plant body is diploid—chromosome number of 44. Lignin test: Positive Cuticle: Present Leaves: Present—large with branched veins. Underside has sori (containing haploid spores). Roots: Present—branch from the inside. Stem: Present—vascular tissue (xylem & phloem) present. Life History: Diploid sporophyte dominant generation. Haploid spores germinate into heart-shaped, haploid, gametophyte. Water required for fertilization; no seed is produced. Diploid zygote develops into sporophyte. Explain which domain, kingdom and phylum you believe this plant should be classified…arrow_forward
- CUÁ Glycine A C C Newly formed molecule Glycine Arginine Proline Alanine A C C CC G GGAUUGGUGGGGC Structure X I mRNAarrow_forwardAdaptations to a Changing Environment Why is it necessary for organisms to have the ability to adapt? Why is the current environment making it difficult for organisms like the monarch butterfly to adapt? Explain how organisms develop adaptations.arrow_forwardArtificial Selection: Explain how artificial selection is like natural selection and whether the experimental procedure shown in the video could be used to alter other traits. Why are quail eggs useful for this experiment on selection?arrow_forward
- Don't give AI generated solution otherwise I will give you downwardarrow_forwardHello, Can tou please help me to develope the next topic (in a esquematic format) please?: Function and Benefits of Compound Microscopes Thank you in advance!arrow_forwardIdentify the AMA CPT assistant that you have chosen. Explain your interpretation of the AMA CPT assistant. Explain how this AMA CPT assistant will help you in the future.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning