SC 135 - Third Exam 2003
ANSWER KEY
MULTIPLE CHOICE. On the line to the left, place the letter of the choice that best answers the question. Three Points Each. NOTE: "e" answers are never the correct answer.
1. All gametes should have what trait in common?
___B___ a. They all should be mobile
b. They all should be haploid
...they have only 1 set of chromosomes, so when they get together to
form a zygote, it will have 2 sets (diploid)
2. New York fish have concentrations of PCBs in their fatty tissues due to
___A___
a.
Bioaccumulation
b.
Mutation
c. ATP processes
d. Snow cover effects
e. A questionable - one could say fishy - lifestyle
...they eat lots of little animals that themselves ate lots of little animals
that each had a bit of PCBs in them - at each step up the chain, more
and more accumulates.
3. Nitrogenous wastes result from processing of
___A___
a.
Protein
b.
Chlorophyll
c. Genes
d.
Lipids
e. Dirt and slime
...they have nitrogen in them, and are often broken down.
4. Which depends upon the products of anaerobic organisms?
___D___ a. Corn
farming
b. Soda bottling
c. Mushroom farming
d. Bread baking
e. Most jokes made by middle-school males
...baker's yeast is an anaerobic organism that makes carbon dioxide
in dough, making it rise.
5. Whether an allele is dominant or recessive is dependent upon
___C___ a. How often it is
passed
on
b. Actual DNA sequence
c. The effect of the coded
protein
d. All of these
e. It basic personality
...the code itself can't be dominant - only the action of what it codes for.
6. The second law of thermodynamics is connected to which statement?
___C___ a. Materials in a food
chain get recycled
b. Enzymes have optimal temperatures
c. Energy moving up a food chain gradually is lost as heat
d. Energy frequency is connected to energy wavelength
e. "I don’t remember what the second law of thermodynamics is."
...this is the law of entropy, that things fall apart and lose
random (heat)
energy unless there's a lot of energy input. In a food chain, the input
is all at the beginning - from there, it gradually fritters away.
7. A point mutation occurs at what "point"?
___A___
a. DNA
base
b. Centromere
c. Chromatid
d. Anaphase
e. A mutation point
...just match the term to part of the definition.
8. Minerals in the diet are often used in the body in
___B___ a.
Respiration
b. Cofactors
c. Chromosomes
d. Mitosis
e. Nasty ways when nobody’s looking
...they aid enzyme processes, or are necessary for a protein to be fully
active.
9. Glycolysis leads into what stage?
___C___ a.
Mitosis
b. Calvin
Cycle
c. Krebs Cycle
d. Meiosis
II
e. Adolescence
...it's the first part of aerobic respiration, and c is the next.
10. Which are involved at the very beginning of
photosynthesis and the very end
of aerobic respiration?
___A___
a. Oxygen &
Water
b. Carbon Dioxide & Water
c. Oxygen &
Glucose
d. Carbon Dioxide & Glucose
e. What you expect and what you really get
...Water supplies electron-carrying hydrogen at the beginning of
photosynthesis (which leaves oxygen), and oxygen picks up
electron-carrying hydrogen at the end of aerobic respiration,
making water.
11. Any trait produced by a metabolic pathway would be a
___B___ a. Homologous
trait
b. Multiple gene trait
c. ATP-linked
trait
d. Recessive trait
...There's always a tricky one. A pathway is multi-step, needing
multiple enzymes coded for by...
12. If in visible light, wavelengths go
from long at the red end to short
at the violet end, which statement should be true?
___C___ a. All visible light
must be at the same frequency
b. Red would have a higher frequency than blue
c. Blue waves would have more energy than red waves
d. Green waves would have no energy
e. Is it bad if I’m starting to see colored spots-?
...This requires knowing the relationship between wavelengths,
frequency (longer waves = lower frequency), and energy
(higher frequency = more energy)
SHORT ANSWER.
Answer any eight of the following
questions for 4 Points Each.
Note: if you answer more than eight, only the first eight will
be corrected.
You can get partial credit on these answers.
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1. What, in general terms, are coupled in coupled reactions? ...exothermic reactions supply energy to endothermic reactions. |
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2. What is a karyotype? ...a combination of chromosome number and the individual types of chromosomes, close to a unique trait for every species. |
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3. What are two different uses for carotenoids in plants? |
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Capture light energy for photosynthesis |
Used to color flowers & fruits |
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4. How are duplicate chromosomes separated for cell division in prokaryotes? ...they attach to special hooks on the inside of the cell membrane, away from the division line of the cell. |
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5. Briefly explain why each statement is true - (Don’t just reword the statements!) |
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There is more
This is the bottom of |
There are more
There are more |
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6. There are two forms of genetic redundancy. Briefly explain how one of them works. ...point mutation changes a codon, but same or chemically similar amino acid produced.
...crossing over mistakes sends on extra gene copies, allowing evolution
of one without |
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7. What are two different ways that gender is set in separate-sex organisms? |
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Unmatched chromosomes (XX - XY). |
A response to environmental factors not set at conception. |
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8. Molecule |
How many phosphates? |
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ATP |
3 (Triphosphate) |
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AMP |
1 (Monophosphate) | |
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9. When the protein-digesting enzyme pepsin moves from the stomach (pH around 2.5) to the small intestine (pH around 8), what must be done to deactivate the enzyme? ...nothing - it won't work at the new pH level.
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10. What are two things that happen during meiosis I that do not happen during mitosis? |
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| Chromosomes
line up as homologous pairs. Pairs separate during anaphase. |
Double strands do NOT separate. |
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11. What, according to current theory, are two different sources of energy that might have been available to aid the assembly of molecules in Earth’s primordial soup? |
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| Sunlight. UltraViolet light. Lightning. |
Volcanic heat / hot chemicals. |
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12. In organisms, most ATP is made from what sub-process (a part of a main process)? ...electron transport chains (in both photosynthesis and aerobic respiration)
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13. What atmospheric effect is probably common to all of the causes of mass extinctions in the past, and why? ...something that blocks sunlight, shutting off photosynthesis and the first step of the food chain.
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14. What specifically does a catalyst do to speed up a chemical reaction? ...it reduces the activation energy, the energy needed to get things reacting.
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15. Briefly explain how an oxygen debt is built up ...a muscle cell, active but deprived of oxygen, will keep at the anaerobic stage at respiration, building up lactic acid that will eventually have to be processed with oxygen.
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LONG ANSWER.
Answer any four of the following questions for Eight
Points Each.
Note: if you answer more than four, only the first
four will be corrected.
You can get partial credit on these answers.
1. For this starting gene stretch of DNA complete the requested sequences -
DNA
_______________________________________________________________
strand T
A C A G G C A C T T
T C C A G T C A T T
mRNA
Strand
Coded Amino
Acid Sequence
[start] - serine - valine - lysine - glycine - glutamine - [stop]
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2. For the main photosynthesis reactions: |
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Name: |
Materials or Energy Used |
Materials Produced |
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LIGHT-DEPENDENT REACTION |
Water & Light |
ATP & Oxygen |
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LIGHT-INDEPENDENT REACTION |
ATP & Carbon Dioxide |
Glucose |
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3. Answer the questions for this graph of temperature and enzyme-aided reaction rate - Why is the rate X Why is the rate INCREASING * /\ * DECREASING Reaction here? * What is * here? * this point * Rate Molecules move X called? X Enzymes are unwinding / faster with temp. * * denaturing. rise. * OPTIMAL * * TEMPERATURE * * * * * * * * * * * * * * * * * * * * * * * * * * * _________________________________________________________________________________ TEMPERATURE --------> |
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4. Draw and label the progress, showing the cells, of the meiosis that makes... |
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SPERM 1 CELL ------> 2 CELLS --------> 4 SPERM
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EGG
1 CELL -------> 1 CELL
+
--------> 1 EGG
CELL +
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5. Briefly describe three different ways that a molecule can be used to inhibit the activity of an enzyme. |
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Block active site access by attaching there. |
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Block active site access by attaching somewhere other that the active site. |
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Change overall enzyme shape so active site doesn't work. |
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| Bind substrate so it won't attach to enzyme. | |
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6. For the four phases of mitosis (remember, one of the phases is not part of division!), name the phases in order and for each one, describe one thing that occurs only during that phase. |
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PROPHASE |
Chromosomes become visible; Nuclear envelope disappears; Spindle forms & attaches to chromosomes; Nucleolus disappears; Chromosomes move to cell equator. |
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METAPHASE |
Chromosome strands pop apart at centromere. |
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ANAPHASE |
Chromosomes migrate toward poles; Cell plate forms. |
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TELOPHASE |
Chromosomes become invisible; Nuclear envelope reappears; Spindle detaches from chromosomes and goes away; Nucleolus reappears. |
NO KEY FOR BONUS QUESTIONS.
Answer as many as you are able. Wrong answers will not result in points being lost from the main exam. You can get partial credit on these answers.
Humans are farthest up a food chain when we eat what sort of food? Three Points.
What does the theory of panspermia propose? Three Points.
What is Occam’s Razor? Four Points.
What common biological function is performed by irreversible enzyme inhibitors? Three Points.
What is "odd" about the basic definition of a vitamin? Three Points.
What sort of animal can see ultraviolet light? Three Points.
Photosynthesis may have started from a combination of two processes needed by hydrothermal vent organisms - what two processes? Three Points each.
Researchers in what two areas of human health are interested in telomeres? Three Points Each.
During mitosis, what important feature of a spindle fiber is related to its length? Three Points.