Constructive Response Practice for LE Exams
Scientific Method
A television advertisement claims that a certain brand of cough drop reduces coughing
for 8 hours. Describe an investigation that could be used to determine if this claim is
valid. In your answer, include at least a description of:
• the treatment to be given to the experimental group [1]
• the treatment to be given to the control group [1]
• the data to be collected [1]
• when the data should be collected [1]
• one observation that would lead to the conclusion that the claim is valid [1]
Help for Aging Memories
As aging occurs, the ability to form memories begins to decrease. Research has shown
that an increase in the production of a certain molecule, BDNF, seems to restore the
processes involved in storing memories. BDNF is found in the central nervous system
and seems to be important in maintaining nerve cell health. Researchers are testing a
new drug that seems to increase the production of BDNF.
56 Design an experiment to test the effectiveness of the new drug to increase the
production of BDNF in the brains of rats. In your answer, be sure to:
• state the hypothesis your experiment will test [1]
• describe how the control group will be treated differently from the experimental
group [1]
• identify two factors that must be kept the same in both the experimental and
control groups [1]
• identify the dependent variable in your experiment [1]
[4] Allow a maximum of 4 credits, allocated as follows:
• Allow 1 credit for stating the hypothesis the experiment will test. Acceptable
responses
include, but are not limited to:
— Rats that are given the drug will show an increase in BDNF in their brains.
— The drug affects memory formation in rats.
Note: Do not allow credit for a hypothesis that is written in the form of a question.
• Allow 1 credit for describing how the control group will be treated differently from
the experimental group. Acceptable responses include, but are not limited to:
— The control group will not get the drug; the experimental group will.
— The control group will get a placebo.
• Allow 1 credit for identifying two factors that must be kept the same in both the
experimental and control groups. Acceptable responses include, but are not limited to:
— Both groups should have the same number of rats.
— rats of the same age
— kept in same conditions
— given the same food
• Allow 1 credit for identifying the dependent variable in the experiment.
— amount of BDNF found in their nerve tissue
— ability to form/store memories
Chemical reactions
Enzyme molecules are affected by changes in conditions within organisms.
Explain how a prolonged, excessively high body temperature during an illness could be
fatal to humans. Your answer must include:
• the role of enzymes in a human [1]
• the effect of this high body temperature on enzyme activity [1]
• the reason this high body temperature can result in death [1]
Cardinals are birds that do not migrate but spend the winter in New York State. Many
people feed these birds sunflower seeds during the winter months. Explain how the
starches present in the sunflower seeds help the cardinals to survive. In your answer,
be sure to:
• identify the building blocks of starches [1]
• identify the process used to produce these building blocks [1]
• state one way cardinals use these building blocks to survive [1]
Allow a maximum of 3 credits, allocated as follows:
• Allow 1 credit for identifying the building blocks of starches. Acceptable responses
include, but
are not limited to:
— simple sugars
— glucose
• Allow 1 credit for identifying the process used to produce these building blocks.
Acceptable
responses include, but are not limited to:
— photosynthesis
— digestion
— synthesis
• Allow 1 credit for stating one way cardinals use these building blocks to survive.
Acceptable
responses include, but are not limited to:
— as an energy source
— as a building unit for some cell parts
Cells & cells processes
Base your answer to question 56 on the diagram below and on your knowledge of
biology.
In a cell, a variety of structures perform specific functions and interact to maintain
homeostasis. The diagram below represents a typical cell with three cell structures
labeled 1, 2, and 3.
Select one cell structure labeled in the diagram and write its number in the space
below. Explain how the cell structure you selected helps maintain homeostasis in a cell.
In your answer, be sure to:
• identify the cell structure you selected [1]
• state one function of this cell structure [1]
• identify one substance that is often associated with the cell structure you
Selected and state how that substance is associated with the cell structure [1]
• identify one other cell structure and explain how it interacts with the cell
Structure you selected to maintain homeostasis in the cell [1]
Allow a maximum of 4 credits, allocated as follows:
• Allow 1 credit for identifying the cell structure selected.
• Allow 1 credit for stating one function of the cell structure.
• Allow 1 credit for identifying one substance that is often associated with the
cell structure selected and for stating how that substance is associated with
the cell structure.
• Allow 1 credit for identifying one other cell structure and explaining how it
interacts with
The cell structure selected to maintain homeostasis in the cell.
Note: Allow credit for each bulleted response that correctly describes the structure
identified by the student in bullet one (i.e., allow 3 credits if the student incorrectly
identifies structure 1 as a mitochondrion but correctly describes a mitochondrion in
bullets 2 through 4).
Examples of 4-credit responses:
Structure 1
• ribosome
• site of protein synthesis
• amino acid — used to make proteins
• nucleus — the ribosome gets instructions from the nucleus determining which
proteins are produced by the cell
Structure 2
• nucleus
• control of cell processes
• DNA — makes up the chromosomes in the nucleus
• ribosome — nucleus sends instructions to ribosomes for protein synthesis
Structure 3
• mitochondrion
• site of energy release/cell respiration
• ATP — produced in the mitochondrion
• cell membrane — allows glucose to enter cell and be used by the mitochondrion for
energy release
Anatomy & Physiology
Select one human body system from the list below.
Body Systems
Digestive
Circulatory
Respiratory
Excretory
Nervous
Describe a malfunction that can occur in the system chosen. Your answer must include
at least:
• the name of the system and a malfunction that can occur in this system [1]
• a description of a possible cause of the malfunction identified [1]
• an effect this malfunction may have on any other body system [1]
Regulation
Base your answers to questions 59 through 61 on the information below and on your
knowledge of biology.
It has been discovered that plants utilize chemical signals for communication. Some of
these chemicals are released from leaves, fruits, and flowers and play various roles in
plant development, survival, and gene expression. For example, bean plant leaves
infested with spider mites release chemicals that result in an increase in the
resistance to spider mites in uninfested leaves on the same plant and the expression
of self-defense genes in uninfested bean plants nearby. Plants can also communicate
with insects. For example, corn, cotton, and tobacco under attack by caterpillars
release chemical signals that simultaneously attract parasitic wasps to destroy the
caterpillars and discourage moths from laying their eggs on the plants.

Identify the specialized structures in the cell membrane that are involved in
communication. [1]

Explain why chemicals released from one plant species may not cause a response
in a different plant species. [1]

State two advantages of relying on chemicals released by plants rather than
using manmade chemicals for insect control. [2]
Microbiology/ Immunology
Discuss why an individual can have sensitivity to peanuts. In your answer, be sure to:
 Identify the human systems that is responsible for this sensitivity to
peanuts [1]
 Identify the specific type of molecule that triggers an allergic reaction [1]
 State one reason why a person could be allergic to peanuts, but non be
allergic to walnuts [1]
 Describe how this reaction is similar to the rejection of a transplanted
organ [1]
56 [1] Allow 1 credit for identifying the human system that is responsible for this
sensitivity to peanuts as the immune system.
Note: Do not accept circulatory system.
57 [1] Allow 1 credit for identifying the specific type of molecule that triggers an
allergic reaction.
Acceptable responses include, but are not limited to:
— antigen
— protein
— allergen
58 [1] Allow 1 credit for stating one reason why a person could be allergic to peanuts,
but not be allergic to walnuts. Acceptable responses include, but are not limited to:
— One type of antibody only reacts with (fits) one type of antigen.
— Antibody reactions are specific.
— Walnuts and peanuts have different proteins.
— Walnuts and peanuts are made up of different chemicals.
59 [1] Allow 1 credit for describing how this reaction is similar to the rejection of a
transplanted organ. Acceptable responses include, but are not limited to:
— Transplanted organs also have antigens that will stimulate antibodies that will
attack the organ.
— They both stimulate immune responses.
Immunization protects the human body from disease. The success of vaccinations
can be seen in the fact that smallpox has been eliminated worldwide from the list of
common infectious diseases. The only remaining smallpox viruses on Earth are thought
to be those kept in certain research laboratories.
The United States is now committed to the goal of immunizing all children against
common childhood diseases. However, many parents are choosing not to immunize
their children against childhood diseases such as diphtheria, whooping cough, and polio.
For example, the mother of a newborn baby is concerned about having her child
receive the DPT (diphtheria, whooping cough, and tetanus) vaccine. Since these
diseases
are caused by bacteria, she believes antibiotic therapy is a safe alternative to
vaccination.
Discuss the use of antibiotics and vaccines in the treatment and prevention of
bacterial diseases. In your answer be sure to include:
• what is in a vaccine [1]
• how a vaccine promotes immunity [1]
• one advantage of the use of vaccinations to fight bacterial diseases [1]
• one disadvantage
Energy
Explain the phrase “only certain organisms can change solar energy into chemical
energy,”
in the underlined portion of the first paragraph. In your answer be sure to identify:
• the type of nutrition carried out by these organisms [1]
• the process being carried out in this type of nutrition [1]
• the organelles present in the cells of these organisms that are directly involved in
changing solar energy into chemical energy [1]
Genetics
Biological research has generated knowledge used to diagnose genetic disorders in
humans. Explain how a specific genetic disorder can be diagnosed. Your answer must
include at least:
• the name of a genetic disorder that can be diagnosed [1]
• the name or description of a technique used to diagnose the disorder [1]
• a description of one characteristic of the disorder [1]
Ecology
Some scientists are urging that immediate action be taken to stop activities that
contribute to global warming. Discuss the effects of global warming on the
environmentand describe some human activities that may contribute to it. Your answer
must include:
• an explanation of what is meant by the term global warming [1]
• one human activity that is thought to be a major contributor to global warming and
an explanation of how it may contribute to the problem [2]
• one negative effect of global warming if it continues for many years [1]
Evolution
Staphylococcus aureus is a type of bacterium that lives on the skin and in the nostrils
of most people. Generally, it is controlled by the immune system of the body.
Occasionally, the antibiotic penicillin is needed to control the bacterium. However,
some strains of S. aureus have a resistance to penicillin, which makes them hard to kill
and infections difficult to cure.
Explain how the resistance to penicillin affects the S. aureus population. In your
answer, be sure to include an explanation of:
• how the exposure to penicillin affects the survival of some bacteria in the
population [1]
• why the frequency of penicillin-resistant bacteria can change over time within
the population [1]
• how it is still possible to cure patients who are infected with penicillinresistant bacteria [1]
[3] Allow a maximum of 3 credits, allocated as follows:
• Allow 1 credit for explaining how the exposure to penicillin affects the survival of
some bacteria in the population. Acceptable responses include, but are not limited to:
— Bacteria may vary in their susceptibility to penicillin, and resistant ones
survive.
— In the bacteria that survive, there are naturally occurring variations that
provide resistance to penicillin.
— When exposed to penicillin, more of the resistant ones survive.
— Nonresistant bacteria die off.
• Allow 1 credit for explaining why the frequency of penicillin-resistant bacteria can
change over time within the population. Acceptable responses include, but are not
limited to:
— When exposed to penicillin, the frequency of resistant bacteria will increase
as those that are resistant survive and reproduce.
— The resistant bacteria will survive and they will produce offspring that are
resistant.
• Allow 1 credit for explaining how it is still possible to cure patients who are infected
with penicillin-resistant bacteria. Acceptable responses include, but are not limited to:
— Patients can be treated with antibiotics other than penicillin.