Organismal Biology Ch. 25

25 July 2022
4.7 (114 reviews)
16 test answers

Unlock all answers in this set

Unlock answers (12)
question
Which statement shows population thinking?
answer
Variation among individuals in a species is real and important.
question
What is plausible evidence supporting the hypothesis that birds evolved from dinosaurs?
answer
Fossilized transitional forms are discovered that possess features of birds and dinosaurs yet are difficult to classify into either group.
question
Why are human and chimpanzee DNA 96 percent similar?
answer
The two species descended from a recent common ancestor.
question
Which is an example of a structural homology?
answer
Vertebrate forelimbs have the same number and arrangement of bones. A homology is a similarity between species, due to evolution altering and using what is already in existence.
question
What is biological fitness?
answer
Biological fitness measures the reproductive success of an individual relative to others in the population.
question
List the four postulates of natural selection.
answer
Variation in population, heritable variation, selection, differential survival or reproduction
question
What is an accurate combination of postulates 1 and 2 of natural selection?
answer
Heritable variation exists for traits among individuals in a population.
question
Which is an accurate combination of postulates 3 and 4 of natural selection?
answer
Individuals experience differential success in their ability to survive or reproduce.
question
Does the ability of a Mycobacterium tuberculosis cell to infect a new host depend on its drug-resistant phenotype?
answer
No, drug-susceptible cells and drug-resistant cells are equally likely to infect a new host.
question
Describe the evolution by natural selection of Mycobacterium tuberculosis bacteria in their new environment.
answer
The drug-resistance trait is an adaptation to the environment in which human hosts are medicated with the antibiotic rifampin.
question
In the United States today, about half of the corn crop is genetically engineered with a protein that is toxic to corn borers, an insect pest of corn. What conditions would be necessary for evolution of resistance to the toxic protein to occur in the corn borer?
answer
The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein. The resistant corn borers must survive better or reproduce more than nonresistant corn borers.
question
True or false? It would be difficult to assess whether the drug-susceptible or drug-resistant phenotype in a population of Mycobacterium tuberculosis was more fit in an environment without antibiotics.
answer
True. In an environment without antibiotics, individual cells probably would not differ in their reproductive rates or their survival. Without the application of the drug (antibiotic), it would be very difficult to analyze any differencesโ€”one wouldn't even be able to sort the cells!
question
Why is the continual use of the antibacterial triclosan in soaps a potential health risk?
answer
Bacteria could evolve a resistance to commonly used antibiotics.
question
In biology, an adaptation is defined as _____.
answer
a heritable trait that increases the fitness of an individual in a particular environment
question
Do individuals change when natural selection occurs? Why or why not?
answer
No. Individuals do not change, but the population does.
question
Which statement about adaptation is correct?
answer
The adaptive value of a trait varies as the environment changes.