Transcript Free Response Reviewx

Free Response Questions
14 Full Questions 2006-2012
2006: Cell Structure and Function
• A major distinction between prokaryotes and
eukaryotes is the presence of membranebound organelles in eukaryotes.
Prokaryotic and eukaryotic cells have some nonmembrane-bound components in common.
Describe the function of TWO of the following
and discuss how each differs in prokaryotes and
eukaryotes.
• DNA
• Cell Wall
• Ribosomes
Explain the endosymbiotic theory of the
origin of eukaryotic cells and discuss an
example supporting this theory.
2006 B: Structure and Function
• The relationship of structure to function is one
of the major themes in biology. For three of
the following structure/function pairs,
describe the structure and then explain how
the function is related to the structure.
Enzyme structure/catalysis
mRNA structure/catalysis
Cell membrane structure/signal
transduction
Membrane protein structure/active
transport or facilitative diffusion
2011 Exam: Water Potential and
Transpiration
• Identify and explain THREE different structural
or physiological adaptations that could
account for the different transpiration rates of
species A and B.
• Water potential (Ψ) is described by the
following formulas.
• Discuss the variables in both formulas and
how they affect water potential.
2006 B: Transpiration
• Identify how two different environmental
factors could be involved in the daily
fluctuations shown above.
• Discuss the mechanisms involved in the
uptake and transport of water by vascular
plants.
• Discuss the role of water in the normal
functioning of plants.
2009 Exam: Metabolism
ATP and GTP are primary sources of energy for biochemical
reactions.
(a) Describe the structure of the ATP or the GTP molecule.
(b) Explain how chemiosmosis produces ATP.
(c) Describe TWO specific cell processes that require ATP and
explain how ATP is used in each process.
(d) An energy pyramid for a marine ecosystem is shown
below. Label each trophic level of the pyramid and provide an
example of a marine organism found at each level of this
pyramid. Explain why the energy available at the top layer of
the pyramid is a small percentage of the energy present at the
bottom of the pyramid.
Describe the structure of the ATP or
the GTP molecule.
Explain how chemiosmosis produces ATP.
Classical Genetics: 2010 Exam, Q3
• A new species of fly was discovered on an island
in the South Pacific. Several different crosses
were performed, each using 100 females and 100
males. The phenotypes of the parents and the
resulting offspring were recorded.
• Cross I: True-breeding bronze-eyed males were
crossed with true-breeding red-eyed females. All
the F1offspring had bronze eyes. F1 flies were
crossed, and the data for the resulting F2 flies are
given in the table below.
• Cross II: True-breeding normal-winged males
were crossed with true-breeding stuntedwinged females. All the F1 offspring had
stunted wings. F1 flies were crossed, and the
data for the resulting F2 flies are given in the
table below.
• Cross III: True-breeding bronze-eyed, stuntedwinged males were crossed with truebreeding red-eyed, normal winged females.
All the F1 offspring had bronze eyes and
stunted wings. The F1 flies were crossed with
true breeding red-eyed, normal-winged flies,
and the results are shown in the table below.
What conclusions can be drawn from cross
I and cross II? Explain how the data
support your conclusions
for each cross.
What conclusions can be drawn from
the data from cross III? Explain how
the data support your conclusions.
Identify and discuss TWO different factors that would
affect whether the island’s fly population is in HardyWeinberg equilibrium for the traits above.
2012 Q3 DNA Processing
Information flow in cells can be regulated by various mechanisms.
• (a) Describe the role of THREE of the following in the regulation of
protein synthesis:
• RNA splicing
• repressor proteins
• methylation
• siRNA
(b) Information flow can be altered by mutation. Describe THREE
different types of mutations and their effect on protein synthesis.
(c) Identify TWO environmental factors that increase the mutation rate
in an organism, and discuss their effect on the genome of the
organism.
(d) Epigenetics is the study of heritable changes in the phenotype
caused by mechanisms other than changes in the DNA sequence.
Describe ONE example of epigenetic inheritance.
2007 B: Transcription and Translation
A molecule of messenger RNA (mRNA) has just
been synthesized in the nucleus of a human cell.
a) What types of modifications may occur to this
RNA before it leaves the nucleus?
b) Once in the cytoplasm, how is the mRNA
translated into protein?
c) If the cell is a secretory cell, how is the protein
from part b) eventually targeted, packaged, and
secreted to the exterior of the cell?
2009 B Exam: Biotechnology
• Describe how a plasmid can be genetically
modified to include a piece of foreign DNA
that alters the phenotype of bacterial cells
transformed with the modified plasmid.
Describe a procedure to determine which
bacterial cells have been successfully
transformed.
• Describe how a plasmid can be genetically
modified to include a piece of foreign DNA
that alters the phenotype of bacterial cells
transformed with the modified plasmid.
• Describe a procedure to determine which
bacterial cells have been successfully
transformed.
2007 Exam: Biotechnology
Using the circle provided, construct a labeled
diagram of a restriction map of the plasmid.
Explain how you developed your map.
Describe how:
• Recombinant DNA technology can be used to
insert a gene of interest into a bacterium
Describe how:
• Recombinant bacteria could be identified
Describe how:
• Expression of a gene of interest could be
insured
2006 Exam: Population Biology
• According to fossil records and recent published
observations, two species of leaf-eating beetles
(species A and B) have existed on an isolated island in
the Pacific Ocean for over 100,000 years. In 1964 a
third species of leaf-eating beetle (species C) was
accidentally introduced on the island. The population
size of each species has been regularly monitored as
shown in the graph above.
• Propose an explanation for the pattern of
population density observed in species C.
• Describe the effect that the introduction of
beetle species C has had on the population
density of species A and species B. Propose an
explanation for the patterns of population
density observed in species A and in species B.
Predict the population density of species
C in 2014. Provide a biological
explanation for your prediction.
Explain why invasive species are often
successful in colonizing new habitats.
2006 B Energy in Ecosystems
• In many ways, all organisms in a food web can
be said to be solar-powered. The producer
level of the food web is responsible for the
transformation of the solar energy into a form
that can be used by other living organisms.
• Discuss the role of green plants in
transforming the Sun’s energy into a form that
can ultimately be used by heterotrophs.
• Discuss the flow of energy from producers
through top carnivores in a food web in terms
of the laws of thermodynamics.
2010 B Ecology Experimental Design
• On a trip to a dense forest, a biologist noticed
that millipedes (small invertebrates) were
plentiful under logs but were rarely seen in
any other location.
(a) Propose THREE environmental variables (two
abiotic and one biotic) that could explain why
millipedes are found more frequently under
logs.
• (a) Propose THREE environmental variables
(two abiotic and one biotic) that could explain
why millipedes are found more frequently
under logs.
• (b) For ONE of the abiotic environmental variables
you chose above, design a controlled experiment to
test a hypothesis that this factor affects the
distribution of millipedes on the forest floor.
Describe data that would support your hypothesis.
• Suppose that you were examining the
distribution of a plant, instead of the millipede.
Describe modifications in the experiment that
you designed in (b) that would be required to
determine whether the abiotic factor you chose
affects the distribution of the plant.
2008 B: Hardy-Weinberg
• What is the frequency of each genotype (AA,
Aa, and aa) in this population?
• What is the frequency of the dominant
phenotype?
• How can the concept of Hardy-Weinberg
equilibrium be used to determine whether
this population is evolving?
• Identify a particular environmental change
and describe how it may alter allelic
frequencies in this population.
• Explain which condition of Hardy-Weinberg
equilibrium would not be met.
2011 exam, 3c
• Discuss TWO prezygotic isolating mechanisms
that prevent hybridization between two
species. Include in your discussion an example
of each mechanism.