29. A sh is removed from a contaminated lake. You determine that a particular toxin is present
in im cells at a concemration X = 15M ngfi. You place the sh in a tank full of clean water [X
= pgfL], and measure the toxin concentration in the sh cells over
23. The molecules helm are often moved into or out of cells during biological processes. Decide
whether or not theyr would be able to cross the Cell membrane lime-l]? without the help of a
.- H C
0+ 3 OH
hydronium alanine [a
Base your answers to questions 5 through T on the information below and on your knowledge of
biology: The illustration is of a Tasmanian devil suffering from facial canter.
2?. The relationship of structure to function is one of the major themes in biology. Describe the
structure of enzymes and then explain how the function of enzymes is related to the
0 3-D shape that resuim from folding of polypepti
universe would not be increasing.
3?. Reduced organic compounds tend to contain stored energy in EH bonds. As a general rule,
the greater the number of [3H bonds, the greater the amount of potential energy stored in
the molecule. Answer each question in t
31. According to the data, the mice at 1DC demonstrated greater oxygen consumption per gram
of tissue than did the mice at 25C. This is most like]? explained by which of the following
a. The mice at 10C had a higher rate ofATP production than
The student predicted that the contractile vacuole would contract fewer times in one minute in a
solution that had a higher concentration of salt than that found in typical pond water.
25. This prediction is most likely.
a. correct, because a high concent
In the experimental investigation. paramecia were placed in salt solutions of increasing osmolarity.
The rate at which the contractile vacuole contracted to pump out excess water was determined and
plotted against osmolarity of the solutions. as shown in
b. What is the role of protein ldoase in this process?
II Protein ldnase is an enzyme that adds a phosphate group to a target
molecule from ATP.
or This results in the target molecule changing shape and thereby changing its
or A neth-actiyated t
b. After making your hypothesis, you test it by measuring the toxin levels in the sh at
various mes during its 10 days in the tank. You observe that the level oftoxin in the
sh drops from 1,5DU pgjL to "FED ML and then stabilizes at TED ugfl. You test
39. The evolution of photosvthesizing organiSms on Earth and the development of an
oxygen-rich environment led to a rapid diversication oflife. Explain why there is an
evolutionaryr advantage to an organism that requires oxygen to live compared to one tha
11. Based on your knowledge of the polarity of water molecules, the solute molecule depicted
in the model below is most likely.
a. positively charged. a w
b. negatively charged. ,
c. without charge. ?
12. A carbon skeleton is covalently bonde
33. In cell respiration, what is the name of the process where glucose is broken down into
a. Electron transport chain
b. Krebs cycle
c. Link reaction
34. The chemical reaction for photosynthesis is
BEE!2 + IZHED + light energy 1 C
35. Life cannot exist in a completely closed symmm [no energy or matter comes into or out of the
system]. Explain why this is TRUE based on the Second Law of Thermodynamics.
For life to exist in a completely closed system there must he more exergonic proc
111-. The R group or side chain of the amino acid serine is cfw_Hz-UH. The R group or side chain of
the amino acid leucine is -EH2-EH-[EH3]2. Where would you expect to find these amino acids
in a globular protein in aqueous solution?
a. Eerine would be in
4D. Which step below would he the m step in a signal transduction pathway?
a. Phosphorylation of proteins
b. Activation of a protein
c. Change in gene expression
:1. Binding a ligand to a receptor
41. Phosphorylation cascades involving a series of protein
response; phagocyte activation; Ab secretio n: clonal selection
45. The relationship of structure to function is one of the major themes in biology. Describe the
structure of cell membranes AND explain how signal transduction is related to the
+3. The virus that causes the bird u can attach to cells ofthe lWEI' part of the respiratory
system in humans; but not to the cells of the upper respiratory system. The most likely
rEason for this is that thEse two groups of cells have different.
a. DNA c
3. A ductc-r discnvers that her patient can prcduce antibn dies against snme bacterial
pathogens, but he is unable to protect himself against viral infections. The dnctnr suspecm a
disurder in her patients.
a. B cells.
b. 13. plasma cells.
c. cvtetnxic T
EB. Chloroplast thylakoids can he isolated and puried for biochemical experiments. Shown
below is an experiment in which pH was measured in a suspension of isolated thylakoids
before and after light illumination [rst arrow]. At the time indicated by the s
5. Using the terms anljgens and antibodies, explain why the tumor cells are ignored by the
immune system in Tasmanian devils.
Acceptable responses include, but are not limited to:
The tumor cells might lack antigens that the antibodies can recogni
19. Which of the following is a major cause of the size limits for certain types of cells?
a. limitation on the strength and integrity of the plasma membrane as cell size
b. eI.nJlutionar_l,Ir progression in cell size: more primitive cells have
6. Results from an experiment indicated that 1'asrnanian devils that showed signs of tumor
regression had antibodies that were not present either in animals that did not have DFTI or
had normally progressing DFTD. Explain the signicance of these rasulis.
21. A patient has had a sericus accident and last a [ct afblccd. In an attempt tc replenish bed?
uids. distilled water-equal tn the 1wnlane c-f blend lest-is transferred direcr.l],lr intn nne cf
his 1reins. What 1will be the most probable result ufthis tr
Boseyouranswers to questions 25 through 2? on the infhrmo tion and diagram below as well as on
your knowledge ofhiologv
Using a microscope and a wet-mount slide; a student observed a pond water sample containing
paramecia, which are single-celled freshwat
Base your answers to questions 3 through ii) on the information below and on your lmmvledge of
Dver EILDUU organ transplants were performed in the United StatES in em 5. Until the middle of the
2|th century, transplanting complex organs; such as
'18. A student is given four samples and told theyr are lysine [an amino acid], lactose [a
disaccharide]. insulin [a protein hormone], and RNA. The samples are in test tubes marked
'1, 2. 3 and 4, but the student doesnt i-mow which compound is in Twhich t
16. The diagram below shows the chenca] structure of cholesteroL which is a key component
of membrane structure.
Is the cholesterol molecule mostlyr polar or mostlyr nonpolar? Explain.
in cholesterol is mostly nonpolar
o it consists primarily.r of C
r; $Canals :3):
marge CWadlun of
Canals take up vacuole expels
waler from >:( water from cell
He decided to determine ifthe canoentration of salt in the environment of the paramecium
would affect the rate at which the contractile vacuole wold
2. Which ofthe following represents the correct sequence of events when the ho Ely is
responding to a bacterial infection?
I. Antigen presentation by macrophages
II. Activation of B-cells
III. Activation ofhelper T-cells
a. I, II, III
b. L II],]I