Download Exam 5 Review - Iowa State University

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Exam 5 Review
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Kelly
Biol 211 (1)
Roe
4/6/14
1. Which of the following statements is false about genetic drift?
a) Genetic drift is one cause of microevolution
b) Genetic drift is the random change in allele frequencies in a population
c) Genetic drift has a stronger affect on really small populations
d) Genetic drift can predict allelic frequencies of each generation
e) All statements are false
2. Natural selection can affect the human population. A good example of this is human birth
weight. Babies of low weight lose heat more quickly and get ill from infectious disease more
easily, whereas babies of large body weight are more difficult to deliver through the pelvis. Thus,
for both larger and smaller babies have a high rate of baby mortality. In contrast, infants of a
more medium weight survive much more often. This is a classic example of _____ selection,
where selection favors ____.
a) stabilizing; individuals at one extreme of a distribution
b) directional; individuals at one extreme of a distribution
c) stabilizing; individuals with intermediate phenotypes
d) diversifying; maintenance of genetic diversity
e) diversifying; individuals with intermediate phenotypes
3. __________ isolation is an example of a prezygotic barrier where two species of trout
breed at different seasons.
a) Gametic
b) Temporal
c) Behavioral
d) Habitat
e) Mechanical
4. The formation of a land bridge between North and South America about three million years
ago should have resulted in which of the following?
I. allopatry of marine populations that were previously sympatric
II. sympatry of marine populations that were previously allopatric
III. sympatry of terrestrial populations that were previously allopatric
a) I
b) II
c) III
d) I, II
e) I, III
5.) Which group is composed of people who felt that species were fixed and unchanging?
A) Lamarck & Darwin
B) Plato & Darwin
C) Aristotle & Lamarck
D) Plato & Aristotle
6.) Charles Darwin was the first person to propose
A) that organisms evolve
B) that the earth is older than a few thousand years
C) a mechanism for how organisms evolve
D) a mechanism for how organisms evolve that was supported by evidence
E) a way to use artificial selection to domesticate plants and animals
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7.) The two principles advanced by Lamarck for how organisms evolve were
A) use and disuse & inheritance of acquired characteristics
B) use and disuse & decent with modification
C) natural selection & decent with modification
D) natural selection & use and disuse
8.) Natural selection operates at the level of the _____________ whereas evolution occurs at the level of
the ______________.
A) population, individual
B) gene, population
C) individual, population
D) individual, gene
9.) A population is in Hardy-Weinberg equilibrium There are two alleles A and a. The frequency of allele
a is 0.2 What is the frequency of the A allele?
A) 0.2
B) 0.4
C) 0.1
D) 0.8
10.) In the above population (which is in Hardy –Weinberg equilibrium) what will the allele frequencies
be after 10 generations
A) A: 0.8, a: 0.2
B) A:0.2, a: 0.8
C) A: 0.4, a:0.4
D) A: 1.0, a:1.0
11.) In the Hardy-Weinberg equation, 2pq refers to the frequency
A) of individual that are homozygous for one of the alleles
B) of individual that are heterozygous
C) of all the alleles in the population
D) of all the genotypes in the population
12.) Which of the following might be occurring if a population is not in Hardy-Weinberg equilibrium?
A) natural selection
B) random matng
C) no migration
D) no gene flow
13.) If the allele frequencies in a population are A: 0.6 and a: 0.4. what is the frequency of the Aa
genotype if the population is in Hardy-Weinberg equilibrium?
A) 1.0
B) 0.52
C) 0.36
D) 0.48
14.) Using the same data what is the frequency of the AA genotype?
A) 1.0
B) 0.52
C) 0.36
D) 0.48
15.) Which type of species concept would you NOT use to determine if a newly discovered population of
an asexually reproducing plant was a distinct species?
A) Biological Species Concept
B) Morphological Species Concept
C) Ecological Species Concept
D) Genetic Species Concept
E) Physiological Species Concept
16.) The largest biologically real unit in nature is:
A) the Genus
B the Family
C) the population
D) the Species
E) the individual
17.) Individuals from two lizards species can mate but the offspring are sterile. This is an example of a
A) pre-zygotic reproductive barrier
B) anatomical incompatibility
C) geographic isolation
D) post-zygotic reproductive barrier
E) behavioral isolation
Theories of Evolution:
Who:
Theory:
(Be
Brief!)
Explain the two main points of Darwin's Theory
1.
Descent with Modification
(What does this encompass?)
2. Natural Selection (What three things
make this possible?)
Why are we not overrun with organisms? (Does this observation fall under 1 or 2?)
Evolution acts on_______________________
Natural selection acts on___________________
Hardy-Weinberg (Measuring Evolution):

What equations are helpful for measurement? What does each term stand for?

What are the 5 conditions for Hardy Weinberg?
-How do we know when evolution is occurring?
-What would be an example of something that does satisfy the conditions?
Practice Problem:
Sickle-cell anemia is an interesting genetic disease. Normal homozygous individuals (SS) have normal
blood cells that are easily infected with the malaria parasite. Thus, many of these individuals become very
ill from the parasite and many die. Individuals homozygous for the sickle-cell trait (ss) have red blood
cells that readily collapse when deoxygenated. Although malaria cannot grow in these red blood cells,
individuals often die because of the genetic defect. However, individuals with the heterozygous condition
(Ss) have some sickling of red blood cells, but generally not enough to cause mortality. In addition,
malaria cannot survive well within these "partially defective" red blood cells. Thus, heterozygotes tend to
survive better than either of the homozygous conditions. If 9% of an African population is born with a
severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria
because they are heterozygous (Ss) for the sickle-cell gene?
Causes of Evolution: Explain briefly. Where is genetic diversity increased? Decreased? Maintained?
1. Genetic Drift
2. Natural Selection (Draw the graph!)
Founder Effect-
Directional Selection-
3. Migration
Diversifying SelectionBottleneck Effect-
Stabilizing Selection-
Macroevolution:
Speciation: What are the 3 steps? (Be brief!)
Step 1:
Step 2:
Step 3:
What is the biological species concept? limitations?
Pre-zygotic Barriers
Post zygotic Barriers
1. Briefly explain these.
2. Which are more energy favorable?
3. Was mating attempted?
4. Mutation
Other things to know:
 Anagenesis
 Clagogenesis
 Sympatric
 Allopatric
 Population
 Artificial Selection
 Gene pool
 Multiple Alleles
 Fixed Alleles



Assortative mating
Keeping Variation
-Diploidy
-Heterozygous Advantage
-Neutral Variation
-Changing Environment
Adaptive Radiation
Examples to Identify:
1. Amish people of Lancaster County, Pennsylvania. They are descended from a few dozen individuals
belonging to an Anabaptist sect in Germany who migrated to Pennsylvania during the early 1700's. Over
the last 40 years of the 20th century, 61 babies with an extremely rare fatal genetic disorder known as
microcephaly were born to 23 Amish families.
2. two populations of flies exist in the same geographical area, but one group lives in the soil and another
lives on the surface of the water.
3. Bush babies, a group of small arboreal primates, are divided into several species. Each species has
distinctly shaped genitalia that, like locks and keys, only fit with the genitalia of its own species.
4. In 1775, a typhoon killed at least 90% of its people, thereby eliminating most of the genetic variation.
One of the 20 survivors was a man named Nahnmwarki Mwanenised. He had achromatopsia, a very rare
genetically inherited recessive eye condition that causes total color blindness and extreme sensitivity to
light. Six generations later, nearly 5% of the island's population had achromatopsia.
5. A plant that is too short may not be able to compete with other plants for sunlight. However, extremely
tall plants may be more susceptible to wind damage
6. South and Central American Indians were nearly 100% type O for the ABO blood system and 100%
positive for the Rh blood system. Since nothing in nature seems to strongly select for or against blood
types, it is likely that most of these people are descended from a small band of closely related "founders"
who also shared these traits.
7. Two mammals of different species produce offspring that are infertile.
8. Some species of crickets are morphologically identical, but can be distinguished by the fact that
females will only respond to the mating songs of males of their own species. Males of other species are
ignored.
9. A plant of extremely variable height that is pollinated by three different pollinators, one that was
attracted to short plants, another that preferred plants of medium height and a third that visited only the
tallest plants. If the pollinator that preferred plants of medium height disappeared from an area.
10. Sea urchins, for example, release their gametes into the water column. In reproductively isolated
species, male and female gametes actually meet, but the sperm does not fertilize the egg.
11. In crosses between different species of irises, for example, the embryos die before seeds form.
12. Outbreeding perennials which have been hybridised to produce garden cultivars, such as Iris and
Watsonia, F2 plants are weaker than their F1 parents but are not sterile.