Explain how and why natural selection has allowed species such as sharks and alligators to remain genetically stable for thousands of years.
answer
Stabilizing natural selection keeps gene frequencies constant in a population. The normal, most common traits are selected for and preserved so only a limited amount of evolution occurs and species can remain unchanged even over long periods of time.
question
Natural selection is best described as _______.
answer
c.
a mechanism of evolution
question
Regular distribution is observed for many organisms due to _______.
answer
c.
interactions between individuals
question
Explain why random distribution patterns for species are the rarest in nature.
answer
Very few species have no pattern of interaction between individuals. It is rare for members of a species to not be attracted to one another or compete for resources, as is required for random distribution which makes this the rarest distribution pattern.
question
Adaptive melanism describes selection for _______.
answer
c.
darker pigmentation
question
Which of the following is not true about the distribution of species?
answer
d.
All the organisms in an ecosystem share distribution patterns.
question
Among humans more boys are born than girls, but women have significantly higher life expectancies. What is the significance of this?
answer
This trend means that men have a higher mortality rate than women. While men start out as a larger percentage of the population, their higher mortality rate means that among the elderly, women are a larger percentage of the population than men.
question
What distinguishes disruptive and directional selection pressures when both select for extreme genetic traits?
answer
While directional selection selects for extreme variation of one genetic trait in a population, disruptive selection selects for both extremes. Disruptive selection eliminates intermediate traits leading to selection at either extreme. Directional selection, meanwhile, preferentially selects for individuals expressing the extreme trait.
question
The most common type of distribution pattern(s) in nature is(are) _______.
answer
c.
cluster
question
Contrast disruptive and stabilizing selections.
answer
While stabilizing selection selects for the most common, normal traits in a population, disruptive selection selects for extremes. Disruptive selection eliminates the very intermediate traits that stabilizing selection preserves.
question
Which of the following species would you most expect to be distributed according to a regular pattern?
answer
d.
creosote bushes
question
Which of the following best describes the relationship between jaguars and panthers?
answer
b.
Panthers are jaguars with predominantly dark or black pigmentation.
question
The rarest distribution pattern in nature is random.
answer
true
question
Stabilizing selective pressures result in _______.
answer
b.
limited evolutionary changes
question
Which of the following is the most obvious sign of cluster distribution in termites?
answer
c.
They are social insects.
question
Natural selection is an evolutionary mechanism by which _______.
answer
b.
advantageous traits become more common in a population
question
Stationary population pyramids are representative of countries with shorter than average life expectancies.
answer
false
question
These two graphs represent _______ and _______ selection.
answer
b.
stabilizing; disruptive
question
Natural selection does not always result in an increase in genetic diversity.
answer
true
question
Disruptive selection events select for _______.
answer
d.
extreme traits
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy
