BIO 102 - Exam 1 Questions
Which of the following describes a genetic mutation:
A "T" is accidentally substituted for an "A" when DNA duplicates
Which of the following variations could be subject to natural selection?
A hyena is born with a spotted fur pattern that allows it to hide in the grass better than its littermates
What is an allele?
A particular version of a gene
Which of the following describes natural selection?
A population in a mammal species varies in the length of their legs, water level rises, and the habitat becomes swampy, the individuals with shorter legs are better able to swim to food; the population evolves to become shorter-legged.
Which of the following hypotheses is testable using scientific method
Bees can see ultraviolet light that humans can't
It is difficult to make a vaccine for HIV for a number of reasons. Which of the following is NOT a reason:
Combination therapies work better than single-drug therapies
Cells that directly kill antigens are called
Cytoxic T cells
Proteins are made in normal cells by
DNA giving code to an RNA, RNA brings the code to the ribosome and translates it by making a protein
If you wanted to see natural selection working in a population of mosquitoes in response to pesticide, how much pesticide should you use?
Enough to kill most but not all mosquitos
True of false: Natural selection occurs on an organism so it can become perfectly adapted to its environment
False
True or false: The goal of natural selection is to make extreme traits more common
False
Evolution that occurs as a result of chance events is called
Genetic drift
Which of the following is the best interpretation of the graph on the left:
High UV and low UV exposure may result in health problems
Drug resistance to to anti-HIV drugs is a serious problem. Which of the following facts about HIV is the most direct reason why drug resistance appears so rapidly?
It has a high rate of mutation
What is the evolutionary origin of light skin in humans
Light skin evolved several times in response to low ultraviolet light levels
Many lines of evidence suggest that human populations aren't distinct races. What keeps us so similar even though adaptions to local conditions have occurred?
Members of different populations mate with each other.
_____ cells of the immune system will help the body respond more quickly if the infectious agent is encountered again
Memory
Which of the following is true about the graph to the right:
Most people in the control group in experiment 1 had cold symptoms for 8 days but in experiment 2, some people had symptoms for 10 and some for 6 days.
A primary source for new, unique genes in a population is
Mutation
The cell pictured to the right is a
Prokaryote because it does not have a membrane bound nucleus
The Sabin vaccine is a liquid containing weakened polio viruses. Vaccinated individuals become protected against polio because the weakened viruses
Promote production of antibodies
The graph on the right includes allele frequency data for several populations of humans. The relative darkness/shading of the bars is an indication of the tone of the skin for people in the populations. The graph provides some evidence that:
Skin color does not correlate with genetic differences among populations.
Which specific defense mechanism protects against foreign organisms that have managed to infect body cells by destroying these cells?
T-cell mediated immune system
A city was intensively sprayed with DDT to control houseflies. The number of houseflies was immediately greatly reduced. Each year thereafter, the city was sprayed again, but the flies gradually increased in numbers until 10 years later, when they were almost as abundant as they were when the control program began. Which of the following most likely explains this?
The DDT killed most flies. The few that were already naturally resistant survived and passed this resistance onto their offspring.
An individual receives a flu vaccine and is well protected for the current flu season. The following flu season, the individuals fails to get another flu vaccine and comes down the flu. What is most likely explanation for vaccine ineffectiveness in the subsequent flu season?
The flu virus mutated, leading to a new strain of virus that could escape detection by the immune system.
On Long Island, New York, there's a population of wall lizards that originated from a group in Italy. Several had been imported to be sold as pets many decades ago, and some escaped and started a new population in this suburban area. This is an example of
The founder effect
Which of the following is the most direct (or first) result of natural selection on a population?
The frequency of some alleles changes in the population
How would you describe the gene changes shown in the figure below? (Different flies)
The frequency of the fast enzyme allele has increased.
Which of the following has contributed to widespread antibiotic resistance?
The genes of a virus code for proteins necessary to make more viruses
In a population, which individuals are most likely to survive and reproduce?
The individuals who are best adapted to the environment
What does it mean to say that experimental results are peer reviewed?
The results are analyzed by other scientists before they are published
The graph to the left is a study from Japan during which the MMR vaccine was replaced with three separate vaccines. The vaccination rate and the cumulative incidence of autism in Japan is plotted within the graph. Which of the following best describes the info in the graph:
The use of separate vaccines had no impact on the rate of autism
Data from an experiment showing the change in tick load among oxen with and without oxpeckers is shown in the graph to the left. Which of the following is true about this data:
There is a high variation in tick loads in treatments with and without oxpeckers
Which of the following steps in the theory of natural selection do humans impact the most to bring about artificial selection?
There is differential survival and reproduction among individuals in a population
Many bacteria carry plasmids containing bacterial genes that are easily and rapidly spread through an entire bacterial colony. Why are plasmids of particular concern to humans?
They carry genes for antibiotic resistance
An antibiotic kills 99.9% of a bacterial population. What will be the result of the continued application of this antibiotic?
Through time, the antibiotic will become less effective at killing the bacteria.
True or false: Levels of ultraviolet light influence both folate and vitamin D production in humans
True
Two unrelated individuals with the same color skin
Would be no likely to have similar alleles for any gene than any two individuals chosen randomly
Your friend was diagnosed with strep throat 2 months ago. She was treated with antibiotics for 10 days, but 2 weeks after treatment, the symptoms returned. She was given a different antibiotic and her symptoms improved again, initially, but then got worse. What is happening?
Your friend was originally infected with some bacteria that were resistant to these two antibiotics and the bacteria multiplied.
Bias is an experiment can occur when
a technician knows which samples are from the control group
A scientific theory is
an explanation supported by a very large amount of experimental evidence
HIV causes diseases in people because it
destroys helper T cells.
A trait that confers ______ in one environment might make an organism less able to survive and reproduce in another environment
fitness
A statistically significant result is one that
is unlikely due to chance
Both B and T cells make up the third line of defense against pathogens but do so in different ways. B cells
make and secrete antibodies
The most trustworthy source of scientific information is
peer-reviewed research publications