SBIOAC EVOLUTION TEST
Name . 2003
04 03
Please answer on sheet provided.. Answer all questions, the
value mark follows each question.
Total
1 In a population of 500 wild flowers,
flower-colour is determined by a single locus with 2
alleles, C and c. 80%
of the gametes in the population have the dominant allele C. What is the predicted genotype frequency in
the next generation if the population is in Hardy-Weinberg equilibrium? (1)
a. CC = 0.8;
Cc = 0.00, cc = 0.2
b. CC = 0.64;
Cc = 0.00; cc = 0.36
c. CC = 0.5;
Cc = 0; cc = 0.5
d. CC = 0.64; Cc = 0.32;
cc = 0.04
2. What is produced by mutation and essential
for evolution to occur?
a. Improvements in organisms
b. Additional DNA
c. A struggle for existence
d. Variation
3. Two different beak sizes occur in a
single population of black-bellied seed crackers (a bird). There are no beaks of intermediate size. Which of the following mechanisms is the most likely cause of this
dimorphism? (1)
a. diversifying/disruptive
selection
b random mating.
c stabilizing selection.
d. directional selection.
4. Directional
selection is . (1)
a elimination
of uncommon forms of alleles
b shift of allele frequencies in a steady, consistent direction
c. the
reduction of intermediate forms of a trait
d. the
selection against extreme forms of a trait
5. Disruptive/diversifying selection is . (1)
a elimination
of uncommon forms of alleles
b shift
of allele frequencies in a steady, consistent direction
c the reduction of intermediate forms of a trait
d the
selection against extreme forms of a trait
6. Match the evolution concepts
appropriately: (2) ½ mark each
C
gene flow A source of new
alleles
D
natural
selection B. changes in allele frequencies due to
chance
A mutation C. migration changing allele frequencies
B genetic drift D. different
rates of fitness in phenotypes
7. True
or False.
Inbreeding changes allele
frequency. (0.5)
8. True
or False. Post-zygotic
reproductive barriers prevent the birth of hybrids.
(0.5)
9. Which
of the following statements best explains the higher proportion of the
dark-colour phenotype observed in the English peppered moth population in
industrialized cities? (1)
a Bird predation was probably an important factor in natural
selection
b. Soot incorporated into the moths due
to industrial pollution.
c. Pollution caused sterility in
light-coloured moths.
d. The moths needed new genes to hide on
darkened trees.
10. The
average weight of a newborn baby is about 3.5 kg. Babies born much lighter or
much heavier than this are at a greater
risk for mortality. This effect
is known
as
(1)
a genetic
drift c disruptive selection
b.
stabilizing selection d directional selection
11 In a population with two alleles for
a particular gene, B and b, the allele frequency of B
is 0.7. The allele B
is dominant over allele b. Assume that population is in equilibrium. (4)
a.
What is the
frequency of the b allele? 0.3 .
b.
What is the
frequency of homozygote dominants? 0.49 .
c.
What is the
frequency of heterozygotes? 0.42 .
d.
What is the
frequency of homozygote recessives? 0.09 .
12. Name the five conditions that must be met in order to maintain
Hardy-Weinberg
equilibrium. (5)
A large population
B no migration
C no mutation
D no natural selection
E random mating
13. Some
species of Anapholes
mosquito live in stagnant water, some in brackish water and others in fresh
running water. What reproductive barrier
is separating these species? (1)
a habitat (ecological) isolation c mechanical isolation
b temporal isolation d post-zygotic barriers
14. In a
population that is in Hardy-Weinberg equilibrium, 16% of the population shows
the recessive trait.
I What is frequency of the recessive allele? (1)
a .16 c .4
b. .04 d .6
II What is the frequency of the dominant allele?
(1)
a
.84 c .6
b .96 d .64
15. True or
False. Island
populations are generally distinct from mainland populations due founder effect. (0.5)
16. True
or False. Evolution
is a ladder leading to more complex organisms (0.5)
17. Evolutionary
change is based mainly on the interaction between ______ and their
________. (1)
a. organisms - gametes
b. populations of
organisms - environment
c. genes - chromosomes
d. offspring -
parents
18.
to say that he invented the idea of _____________. (1)
a. use and disuse of parts
b. change in allelic frequencies by mutation
c. evolution by
natural selection
d. evolution by mutations
19. In each of the following cases, state the
type of isolating mechanism from the list below
AND state whether it is prezygotic
or postzygotic. (5)
A.
behavioural D. habitat G.
hybrid breakdown
B mechanical E. temporal H. hybrid inviability
C hybrid sterility F. none of the above
i.
One of two
species of crickets in an area mates at dusk, the other at dawn.
Type E . pre
or post (circle one)
ii. Female yellow sulfur butterflies avoid mating with a
male using an unfamiliar courtship ritual.
Type A . pre
or post (circle one)
iii. Crossing bears from two different continents produces
cubs that never produce any offspring as adults.
Type C . pre or post (circle one)
iv. Two varieties of sparrows that inhabit lowland valleys
live on opposite sides of the
Type D . pre or
post (circle one)
20. Which of the following is incapable
of evolving? (1)
a. a
flock of geese c the bacteria in your gut
b bread
wheat d your biology
teacher.
21. True or False. Circle one for each question. (2)
a. Disruptive
selection occurs when an intermediate phenotype is favored. T F
b. The
definition of species is based on appearance. T F
c. A
mule is an example of a postzygotic reproductive
mechanism. T F
d. Sexual
dimorphism is present in all species. T F
22.
PLEASE READ THIS
QUESTION CAREFULLY. The Hardy - Weinberg Theory states that in a
population with two alleles, p and q , (p + q) =1.
The frequencies of the alleles are given for the entire population. For example, if the allele p has
a frequency of 0.7, it indicates that p is present in 70% of the gametes in the total population. It cannot
have a frequency of 70% in an individual, that would
not make sense, so the frequencies refer only to a population. When the alleles are in equilibrium (all
conditions are met), the frequencies of the alleles of the next generation can
be represented by (p + q)2.
A If we designate p as the dominant
allele, which of the following shows the dominant phenotype? (1)
a. p2 c.
q2
b. 2pq d. both a
and b
B. If p has a frequency of 0.65, what is
the frequency of q? (1)
a. 0.65 c.
0.5
b. 0.35 d. 1
C. Using the frequency of p = 0.65, give the
following ( assume equilibrium). (1)
the frequency of homozygous dominants .
the frequency of heterozygotes .
the frequency of homozygous recessives .
D The frequency of the dominant
phenotype in a population at equilibrium is 75%. What is the frequency of the
dominant allele? (1)
a. 0.75 c.
0. 25
b. 0.5 d. 1.0
23.
An apple grower discovered his apples
were infested with a fungus. He sprayed the trees with a fungicide, and wiped
out 98% of the fungus, but 6 weeks later the fungus
reappeared. He sprayed with the same fungicide, at the same dose, but only
managed to kill 50% of the fungus. Explain what is happening in terms of evolution
and population genetics. Be brief! (4)
The
mutation that conferred pesticide resistance was present already in the
population at a low frequency. In the first spraying, the vast majority of
fungus was killed because it had no resistance.
Six weeks and many generations later…
The pesticide-resistant
fungus passed that characteristic onto their offspring and they survived the
second spraying. The ones that died in the second spraying were offspring of
those non-resistant fungi that were missed in the first spraying.
The
population is showing microevolution because the frequency of the pesticide
resistant allele is increasing rapidly.
BONUS (1)
The Origin of
the Species is a book that changed
the way we think about ourselves.
Name the author of this book.
(For another
bonus mark, name the ship that he sailed on)
Charles Darwin
HMS Beagle