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Lecture 1

BIOL 1202 Lecture Notes - Lecture 1: Aureus, African Elephant, Cestoda


Department
Biological Sciences
Course Code
BIOL 1202
Professor
Pomarico
Lecture
1

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MASTERING BIOLOGY: CH 22
1. Which of the following observations led to Darwin's major inferences?
a. Members of a population vary in their heritable traits.
b. Although organisms can produce huge numbers of offspring, many of these
offspring do not survive.
2. A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of
the fish are light brown, but about 10% are mottled. This fish species is often prey for
large birds that live on the shore. A construction company dumps a load of gravel in the
bottom of the lake, giving it a mottled appearance. Which of these statements presents the
most accurate prediction of what will happen to this fish population?
a. The proportion of mottled fish will increase over time.
3. Which of these conditions should completely prevent the occurrence of evolution in a
population over time?
a. All phenotypic variation between individuals is due only to environmental
factors.
4. Natural selection is based on all of the following except
a. Individuals adapt to their environments and, thereby, evolve.
5. Given a population that contains genetic variation, what is the correct sequence of the
following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.
a. 2413
6. A biologist studied a population of squirrels for 15 years. During that time, the population
was never fewer than 30 squirrels and never more than 45. Her data showed that over half
of the squirrels born did not survive to reproduce, because of both competition for food
and predation. In a single generation, 90% of the squirrels that were born lived to
reproduce, and the population increased to 80. Which inference(s) about this population
might be true?
a. The amount of available food may have increased.
b. The number of predators that prey upon squirrels may have decreased.
7. Which of the following must exist in a population before natural selection can act upon
that population?
a. Genetic variation among individuals
b. Sexual reproduction
8. If Darwin had been aware of genes, and of their typical mode of transmission to
subsequent generations, with which statement would he most likely have been in
agreement?
a. If natural selection can change one gene’s frequency in a population over the
course of generations then, given enough time and enough genes, natural
selection can cause sufficient genetic change to produce new species from old
ones.
9. The role that humans play in artificial selection is to
a. Choose which organisms breed, and which do not.
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10. Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and
a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?
a. Species X and Y share a greater number of homologies with each other than
either does with species Z.
11. The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be
an example of artificial selection because
a. Humans synthesize methicillin and create environments in which bacteria
frequently come into contact w methicillin.
12. Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta and a
third extant species (Z) is placed in the genus Elephas. Assuming this classification
reflects evolutionary relatedness, which of the following is the most accurate
phylogenetic tree? (The length of the branches reflects evolutionary time.)
a. -------------------[Z
b. [X/Y
13. The horizontal axis of the cladogram depicted below is a timeline that extends from
100,000 years ago to the present; the vertical axis represents nothing in particular. The
labeled branch points on the tree (VZ) represent various common ancestors. Let's say that
only since 50,000 years ago has there been enough variation between the lineages
depicted here to separate them into distinct species, and only the tips of the lineages on
this tree represent distinct species. How many separate species, both extant and extinct,
are depicted in this tree?
a. Six
14. According to this tree, what percent of the species seem to be extant (in other words, not
extinct)?
a. 66%
b.
15. Which of the five common ancestors, labeled VZ, has given rise to the greatest number of
species, both extant and extinct?
a. Both X and Y can be considered to have given rise to the greatest number of
extant and extinct species.
16. Which of the five common ancestors, labeled VZ, has been least successful in terms of
the percent of its derived species that are extant?
a. W
17. Which of the five common ancestors, labeled VZ, has been most successful in terms of
the percent of its derived species that are extant?
a. Z
18. During a study session about evolution, one of your fellow students remarks, "The giraffe
stretched its neck while reaching for higher leaves; its offspring inherited longer necks as
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