CAMPBEL BIOLOGY:CONCEPTS & CONNECTIONS
10th Edition
ISBN: 9780136538820
Author: Taylor
Publisher: INTER PEAR
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 13, Problem 8TYK
Within a few weeks of treatment with the drug 3TC, a patient’s HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?
a. HIV can change its surface proteins and resist vaccines.
b. The patient must have become reinfected with a resistant virus.
c. A few drug-resistant viruses were present at the start of treatment, and natural selection increased their frequency.
d. HIV began making drug-resistant versions of its enzymes in response to the drug.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Which of the following statements accurately describes what we learned about HIV evolution?
a.
HIV is more deadly in Northern Europe, but more transmissible in Africa. That is why there are more individuals infected with the illness in Africa.
b.
HIV shares a most recently common ancestor with Simian Immunodeficiency Virus (SIV) such that SIV evolved as it host-switched from chimpanzees and gorillas into humans multiple times.
c.
Drug development is exceedingly difficult because there are very few drug targets for HIV and AZT (a reverse transcriptase inhibitor) alone is the single most effective treatment for HIV.
d.
Evolution of HIV virions within a person is quite slow such that a blood draw after 1 year of infection would reveal that every single virion would have the exact same sequence.
What is the significance of Pasteur’s experiment to test the germ hypothesis?
a. It proved that heat can sterilize a broth.
b. It demonstrated that cells can arise spontaneously.
c. It demonstrated that some cells are germs.
d. It demonstrated that cells can only arise from other cells.
According to studies of SARS- CoV-2, the typical genetic mutation rate for this virus is 1 mutation every 16 days, and measles every 39 days, on average. Which virus is likely to have the fastest rate of evolution?
A. Ebola
B. flu (influenza)
C. Measles
D. SARS-CoV-2
Chapter 13 Solutions
CAMPBEL BIOLOGY:CONCEPTS & CONNECTIONS
Ch. 13 - Summarize the key points of Darwins theory of...Ch. 13 - Complete this concept map describing potential...Ch. 13 - Which of the following did not influence Darwin as...Ch. 13 - Natural selection is sometimes described as...Ch. 13 - In an area of erratic rainfall, a biologist found...Ch. 13 - If an allele is recessive and lethal in...Ch. 13 - In a population with two alleles, B and b, the...Ch. 13 - Within a few weeks of treatment with the drug 3TC,...Ch. 13 - In the late 1700s, machines that could blast...Ch. 13 - Write a paragraph briefly describing the kinds of...
Ch. 13 - In the early 1800s, French naturalist Jean...Ch. 13 - Sickle-cell disease is caused by a recessive...Ch. 13 - It seems logical that natural selection would work...Ch. 13 - SCIENTIFIC THINKING Cetaceans are fully aquatic...Ch. 13 - A population of snails is preyed on by birds that...Ch. 13 - Advocates of scientific creationism and...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- The method of applying the molecular clock to determine the timing of the most recent common ancestor of HIV to 1930 was used to.... O 1. Test the hypothesis that HIV jumped from a bat population into humans 2. Test whether HIV was circulating in the human population at the same time as the Spanish Flu influenza A virus O 3. Calculate the divergence time between HIV-1 and HIV-2 O 4. Test whether HIV was spread through a contaminated polio vaccine in the 1950s O 5. Estimate the rate of evolution for all human retrovirusesarrow_forwardWhich of the following does not apply to mutations?a. They occur to cause adaptive changes in response to the environment.b. They are usually either harmful or neutral.c. They are only inherited if they occur in a sperm or egg cell.d. They often occur when DNA is copied.arrow_forwardThe media has recently reported that a high number of patients while staying in the hospital, are gettinginfections caused by antibiotic-resistant bacteria. Using evolutionary theory, explain how this could occur.arrow_forward
- According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive, rather than digesting it as food? A. The host cell would have been poisoned if it had digested the engulfed cell. B. The host cell was able to survive anaerobic conditions with the engulfed cell alive. C. The engulfed cell provided the host cell with CO2 D. The engulfed cell provided the host cell with ATP. E. The engulfed cell allowed the host cell to metabolize glucose.arrow_forwardWhich of the following statements correctly describes a process by which bacteria become resistant to antibiotics? A. bacteria reproduce slowly, allowing mutation to become widespread in a population. B. some bacteria produce exotoxins that breakdown antibiotics, rendering them nonfunctional C. conjugation spreads antibiotic resistance genes rapidly in a population D. antibiotics cause mutation in bacteria, making them resistant.arrow_forwardHow do evidences happening in recent times support Evolutionary ideas?1. COVID virus believe to have evolve from other Respiratory viruses2. Antibiotic Resistance in Bacteriaarrow_forward
- The fact that DNA sequences are more similar in more closely related organisms is evidence of what?a. optimal design in organismsb. adaptationc. mutationd. descent with modificationarrow_forwardPlease help with the following: The frequency of the CCR5Δ32 allele varies between populations. Research has shown that individuals with this allele are resistant to HIV with an increased frequency in European populations. This conferred resistance is a direct result of: A. An adaptation to smallpox. B. An adaptation of domesticated animals. C. An adaptation to malaria. D. None of the above. E. An adaptation to thousands of years of exposure to infectious diseases.arrow_forwardOf the following, which is the least plausible hypothesis for why natural selection has not eliminated genes for male homosexuality? a. Perhaps the relatives of a homosexual male have more than an average number of children. b. Homosexual people might spread their genes by helping their brothers and sisters rear their children. c. Maybe there is no gene for homosexuality. Instead, an environmental event produces an epigenetic effect that can be transmitted from one generation to the next. d. Some homosexual men have children.arrow_forward
- If a scientist discovers a new monkey in Paraguay, its genome will probably be MOST similar to that of A. a clam. B. a leech. C. a gorilla. D. a fruit fly.arrow_forwardWhich of the following is unnecessary for adaptation? a. Replication b. Selection c. Time d. Competition e. Variationarrow_forwardWhich of the following must be true for natural selection to occur in an “RNA world”? a. RNA molecules must turn into DNA molecules. b. RNA molecules must undergo mutations. c. RNA molecules must replicate. d Both b and c are correct.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College
Concepts of Biology
Biology
ISBN:9781938168116
Author:Samantha Fowler, Rebecca Roush, James Wise
Publisher:OpenStax College
Genetic Variation and Mutation | 9-1 GCSE Science Biology | OCR, AQA, Edexcel; Author: SnapRevise;https://www.youtube.com/watch?v=bLP8udGGfHU;License: Standard YouTube License, CC-BY