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1) A population of bats feeds on flying insects.
Some of these bats have a gene that results in
much stronger flight muscles than those of the
other bats in the area. Explain how this
variation could lead to evolutionary change
within this species of bat. In your answer, be
sure to include an explanation of:
• competition within the bat population
• survival of various individuals within the bat
population
• how the frequency of the trait for stronger
flight muscles would be expected to change
within the bat population over time
Examples:
— Bats with the variation for
stronger flight muscles would most
likely catch more flying insects than
bats without the gene. — More bats
possessing the gene for stronger
flight muscles would survive than
those without. — Over time, more
bats would possess the variation for
stronger flight muscles.
2) Explain why comparing the vein
patterns of several leaves is a less
reliable means of determining the
evolutionary relationship between
two plants than using gel
electrophoresis.
– Chemical similarities are more
reliable than structural similarities.
– Electrophoresis shows chemical
similarities, which are more
reliable. – Many unrelated plants
have a similar vein pattern.
Base your answer for questions 3 to
4 on the information below and on
your knowledge of biology.
Two adaptations of the monarch
butterfly that aid in its survival are
the production of a certain chemical
and a distinctive coloration that
other animals can easily recognize.
When a monarch butterfly is eaten,
the presence of the chemical results
in a bad taste to the predator.
Although the viceroy butterfly does
not contain the chemical that tastes
bad to a predator, it does resemble
the monarch in size, shape, and
coloration.
3) Explain how the combination of
this chemical and the distinctive
coloration aid in the survival of the
monarch butterfly.
Example: — The predator gets a bad
taste from the monarch butterfly
and then recognizes other members
of that species and does not eat
them.
4) How do the characteristics of the
viceroy butterfly aid in its survival?
Example: — Since the viceroy
butterfly resembles the monarch,
predators that have tasted a
monarch butterfly do not eat
viceroy butterflies.
5) Two cultures, each containing a
different species of bacteria, were
exposed to the same antibiotic.
Explain how, after exposure to this
antibiotic, the population of one
species of bacteria could increase
while the population of the other
species of bacteria decreased or was
eliminated.
Examples: — Organisms with
antibiotic resistance would survive
and reproduce. Others without
resistance would decrease in
number.
)
An insect pest known as the medfly
significantly reduced the orange
crop in California. Pesticides were
used to control the medfly. Using
the concept of natural selection,
explain how the continued use of a
certain pesticide may become
ineffective in controlling this fly.
Your answer must include the
concepts of:
• variation
• adaptive value of a variation
(adaptation)
• survival
• reproduction
Examples: Some medflies have a
variation that provides resistance to
pesticide. ‘When the pesticide is
present, those flies with the
favorable variation will survive to
reproduce and pass the variation to
offspring. A variety of medfly
resistant to the pesticide will result.
7) Growers of fruit trees have
always had problems with insects.
Insects can cause visible damage to
fruits, making them less appealing
to consumers. As a result of this
damage, much of the fruit cannot be
sold. Insecticides have been useful
for controlling these insects, but, in
recent years, some insecticides have
been much less effective. In some
cases, insecticides do nothing to
stop the insect attacks.
Provide a biological explanation for
this loss of effectiveness of the
insecticides. In your answer, be sure
to:
•
identify the original event that
resulted in the evolution of
insecticide resistance in some
insects
•
explain why the percentage of
resistant insects in the population
has increased
•
describe one alternative form of
insect control, other than using a
different insecticide, that fruit
growers could use to protect their
crops from insect attack
Responses include, but are not
limited to: • A mutation (or genetic
change) probably occurred that led
to the resistance to the insecticide
• The percentage of resistant
insects in the population has
increased over the years because
they survived when the insecticide
was used, and were then able to
reproduce and pass on the
resistance
• release natural predators of the
insects; the release of large
numbers of sterile males of insect
species that damage fruits; provide
conditions that help predators of the
insects live in the area; genetically
engineer insect-resistant plants
Base your answer for questions 8 to
9 on the information below and on
your knowledge of biology.
The three great lakes in Africa
(Victoria, Tanganyika, and Malawi)
contain a greater number of fish
species than any other lakes in the
world. Lake Malawi alone has 200
species of cichlid fish. The diversity
of cichlid species in these African
lakes could have been caused by
changes in water level over
thousands of years. According to one
hypothesis, at one time the three
lakes were connected as one large
lake and all the cichlids could
interbreed. When the water level
fell, groups of cichlids were isolated
in smaller lakes as shown in the
diagram. Over time, the groups of
cichlids developed genetic
differences. When the water levels
rose again, the isolated populations
were brought back into contact. Due
to significant genetic differences,
these populations were unable to
interbreed. Variations in water level
over thousands of years resulted in
today's diversity of cich-lid species.
8) As the water level of the lakes
changed, many species of cichlids
survived while others became
extinct. State why some species
survived while others became
extinct.
Examples: – Some species are better
adapted to the environment. – Some
species have greater ability to
compete for food or escape
predators or breed. – natural
selection
9) Each cichlid population is
genetically different from the other
cichlid populations. State one
reason for these genetic
differences.
Examples: – evolution – meiosis –
sexual reproduction – recombination
during fertilization – cross-over –
mutations – natural selection /
isolation
10) Certain insects are kept under
control by sterilizing the males with
x rays so that sperm production
stops. Explain how this technique
reduces the survival of this insect
species.
Responses include, but are not
limited to: If sperm production
stops, then eggs cannot be
fertilized; It reduces genetic
variation by limiting the number of
males that can produce offspring;
Without reproduction no species can
survive.
11) A hawk has a genetic trait that
gives it much better eyesight than
other hawks of the same species in
the same area. Explain how this
could lead to evolutionary change
within this species of hawk over a
long period of time. In your answer,
be sure to include an explanation of:
a. competition within the hawk
population
b. survival of various individuals in
the population
c. how the frequency of the bettereyesight trait would be expected to
change over time within the
population
d. what would most likely happen to
the hawks having the bettereyesight trait if they also had
unusually weak wing muscles
a. Examples: — The hawk with the
better eyesight would compete
more successfully. — The hawks with
the better eyesight would have a
better chance of obtaining food.
b. Examples: — Individuals with the
better-eyesight trait would have a
better chance to survive.
c. Examples: — The frequency of the
better-eyesight trait would increase.
d. Examples: — If the hawks have
better eyesight and weak wings,
they will not have the same
advantage as those with better
eyesight and normal wings.
Base your answer for questions 12 to
14 on the information below and on
your knowledge of biology.
Based on their analysis of the
differences in amino acid sequences
of one kind of protein, scientists
prepared the evolutionary tree
shown below.
12) Older systems of classification
always placed penguins, chickens,
ducks, and pigeons in the bird group
and turtles and snakes in the reptile
group. Does this diagram support
the older system of classification?
Explain your answer.
Examples: — Snakes are in their own
group, rather than grouped with
turtles. — Turtles are on the same
branch as the birds. — Snakes have
one kind of protein that is very
different from that found in turtles
and birds.
13) According to this diagram, the
DNA of which pair of organisms
would show the greatest similarity?
A) penguin and turtle
B) horse and donkey
C) snake and tuna
D) turtle and rabbit
14) According to this diagram, is the
pig more closely related to the dog
or the kangaroo? Justify your
answer.
Examples: — separated more
recently — closer together on the
tree — have a more recent common
ancestor — The protein in the pig is
more similar to that in the dog.
Base your answer on the information
below and on your knowledge of
biology.
Gaurs, which are large oxlike
animals found in South Asia, have
been hunted for sport for many
generations. Most recently, as
human populations have increased,
the gaur’s habitats of forests,
bamboo jungles, and grasslands have
dwindled. The gaur is now
considered an endangered species.
Scientists have succeeded in
preserving endangered species by
cloning. Recently, a gaur was cloned
and the resulting embryo was placed
inside a domestic cow, which then
gave birth to a baby gaur.
15) State one way, other than
cloning, that gaurs might be saved
from extinction.
Examples: — preserving the habitats
in which they live — restricting
hunting of gaurs