BI 171 - Fourth Exam - 1999
KEY - Please note comments after multiple choice selections...
Multiple Choice.
Place the letter of the choice that best answers the question on the line to the left.
Two Points Each. NOTE: "e" answers are never the correct answer.
___A___ 2. A polar body is used for
a. Discarding of chromosome sets
b. Deactivating specific chromosomes
c. Pulling chromosomes apart
[spindle fibers]
d. Anchoring cilia and flagella
[basal bodies]
e. Haute couture runway shows
...right out of notes / book...
___C___ 3. Which types of molecules come in pyrimidine and purine forms?
a. Chlorophylls
b. Protein
c. Nucleic acid bases
d. Carotenoids
e. The ones filed under "P"
...right out of book - this is not always covered so may not be asked...
___B___ 4. One thing that intron and exon combinations produce is the ability to
a. Use different frequencies in photosynthesis
b. Produce a variety of proteins from the same gene stretches
c. Pair up different sorts of homologous chromosomes
d. Move materials in different directions within a cell
e. Produce yet more confusion in the typical student
...covered in notes...
___A___5. Which would carry a single amino acid?
a. Transfer RNA
b. Ribosomal RNA
c. Messenger RNA
d. Nuclear RNA
e. Amino acid-carrying Barbie
...it's the only one that carries anything, really...
___D___6. Experiments with the bread mold Neurospora led to the discovery that
a. Alleles were gene variants
[Mendel]
b. Only DNA was need for accurate information transfer
[viruses]
c. Genes could undergo mutations
[fruit flies]
d. Genes determined specific enzymes
e. No one thinks that mold researchers are sexy
___B___7. A transducer can
a. Move molecules
b. Convert energy forms
c. Flip membrane molecules
d. Reproduce 2 ways
e. Isn't that under my hood somewhere?
...right out of notes / book...
___A___8. Which DNA sequence mutations tend to have the largest effects on the resulting
protein?
a. Deletion
b. Substitution c. Inversion
d. Duplication
e. The ones where they're run over by monster trucks
...anything that changes the reading frame of the codons...
___B___9. DNA was hard to confirm as life's coding molecule because it was thought to be
a. Too complex
b. Too simple
c. Too unstable
d. Too hard to copy
e. Too boring
...broken down for analysis, it has very few components...
___A___10. Traits that are inherited but not passed through DNA are called
a. Epigenetic
b. Extragenetic
c. Nonhomologous
d. Morphological
e. Taxable
...right out of notes / book...
___C___11. Which commonly acts as the reducing agent in photosynthesis?
a. CO2
b. C6H12O6
c. H2O
d. O2
e. Suzanne Somers and the TrunkmasterTM
...only one could reasonably donate the Hydrogens for reduction...
___D___12. Materials taken in and actually used are best described as
a. Consumed
b. Digested
c. Homeoregulated
d. Assimilated
e. The better holiday gifts
...right out of the notes...
___A___13. The main "winding" proteins used in chromatin are
a. Histones
b. Dyneins
c. Kinetochores
d. Kinesins
e. Available at the Chromatin Warehouse at discount prices!
...right out of notes / book...
___A___14. Which are commonly found in parts of cells under mechanical stress?
a. Intermediate filaments
b. Coated pits
c. Doubled membranes
d. Receptor proteins
e. Itty-bitty government regulators
...right out of notes / book...
___B____15. A plasmid is a
a. Photosynthetic organelle
b. Prokaryote gene copy
c. Cellular reproductive structure
d. Receptor type
e. Tiny thing crawling under your sleeve right now
...as long as you don't read it as "plastid," it's
right out of the notes
___B___16. Chlorophyll
a. Absorbs mostly in the green range
b. Releases an electron for each photon of light absorbed
c. Gains an electron for each photon of light absorbed
d. Is a type of microfilament
e. "Chlorophyll" is supposed to be a question?????
...right out of the notes / book...
___D___17. A single starting cell would result in
a. Four functional sperm or four functional egg cells/ova
b. Two functional sperm or two functional egg cells/ova
c. One functional sperm or four functional egg cells/ova
d. Four functional sperm or one functional egg cell/ovum
e. That's one busy cell!
...obviously "functional" is an important word here...
___A___18. Since traits are almost never the result of a single protein working alone, most traits
are considered
a. Multiple-gene traits
b. Linked traits
c. Blended traits
d. Mendelian traits
e. Too embarrassing to discuss in public
...covered mostly in lab and notes...
Short Answer.
Pick NINE questions to answer in the spaces provided.
NOTE: if you answer MORE than nine, only the first nine will be corrected.
Four Points each. Partial credit is possible.
1. In a species, what disadvantages are associated with:
| LOW CHROMOSOME NUMBERS? -less diversity in offspring |
HIGH CHROMOSOME NUMBERS?
-harder to "shepherd" through cell divisions |
...whatever its normal role
or job is...
...prepares for division if
one is coming...
3. Give two examples of different classes of signal ligands.
...includes hormones, alarmones, pheromones, neurotransmitter - any molecule that carries info and binds to a receptor...
...small DNA mutations
produce no or minimal change in coded protein...
...crossing over produces
"extra" genes that can be mutated without disturbing original
function...
5. What are two different things that spindle fibers attach to?
...centromere or kinetochore
- these would be 2 versions of the same thing
...cell membrane for
anchoring purposes...
6. For the Light-Dependent Reaction of Photosynthesis:
| What molecules and/or energy types are
absorbed?
Light and water. |
What molecules and/or energy types are
produced?
ATP and oxygen (also NADH) |
| What molecules and/or energy types are
absorbed?
ATP, carbon dioxide (also NADH, NADPH) |
What molecules and/or energy types are
produced?
Sugar / glucose. |
8. What molecules make up an antenna complex?
...lots of chlorophylls with associated proteins
...DNA replication along the
"back" strand, produced in spurts
10. What is a signal region on a protein used for?
...it determines where the
protein is headed in a cell once it's been made...
11. What are the two major types of signals involved in negative feedback?
...effects and material
levels...
12. Electrons "excited" (but not removed) by absorption of radiation may be in a position to
do one of two different, very significant things. What are they?
...destabilize the atom /
molecule so it reacts more easily...
...return to non-excited
state by reradiating energy in another form...
13. What are two reasons that an organism might undergo a metamorphosis that does not
involve alternations of generations?
...to keep larvae and adults
from occupying same niche (no competition)...
...to produce more mobile
adult for more efficient mate-finding...
14. What are the two functions served by ferredoxin?
..."feed"
into electron transport chain...
..."feed" into
NADPH production and back to reaction center...
15. What two basic characteristics are used to determine a karyotype?
...number of
chromosomes and particular physical characteristics of all
the chromosomes...
16. Briefly describe what each term below means:
Parents
cross
Offspring
Qq
x Qq
----->
qq
Dominant showing,
recessive
hidden
Recessive showing
Long Answer.
Select and answer completely any four of the following questions.
Note: if you answer more than four, only the first four will be corrected.
Seven Points Each. Partial credit is possible.
1. Each one of your answers will start with the DNA ½ strand given!! Fill in the sequences
____________________________________________________________
DNA ½ Strand: C A G G C
A T T C A G C C C A
T A A G C A T C A
Other DNA
Strand:
G T C C G T A A G
T C G G G T A T T
C G T A G T
mRNA
Strand:
G U C C G U A A G
U C G G G U A U U
C G U A G U
How many codons are on this strand? _____8_______
2. Give the name and function of the molecules involved in the four steps of typical transduction pathways.
| RECEPTOR | Picks up external information, send message through membrane |
| G PROTEIN |
Relays information on inner side of message |
| 2ND MESSENGER |
Used to activate next molecules |
| PROTEIN KINASE |
"Turns on" appropriate enzyme, usually by phosphorylation |
3. Describe the main things that happen during each stage that make it different from regular mitosis:
| Meiosis I:
Homologous chromosomes pair up during prophase, may swap pieces, are
separated (but strands are not) at metaphase and anaphase
|
| Meiosis II:
Very little difference - cell only has one set of chromosomes
instead of 2.
|
4. At the points labeled with the stars, attach the appropriate labels from this list:
Violet. X-Ray. InfraRed. Red. Blue. UltraViolet.
Short Wavelength \ <-------------Visible Range --------------> / Long Wavelength
| DNA strands are separated and promoter aids in the production of messenger RNA (mRNA) using RNA Polymerase |
| mRNA goes from nucleus, feeds through ribosome |
| As mRNA moves through ribosome, transfer RNA (tRNA) attaches to it - one tRNA for each codon. |
| tRNA carry in amino acids, one at a time, which
bind as tRNAs connect to codons. |
| Amino acid sequence becomes full-length;
chaperonins aid folding of functioning protein |
|
PROPHASE
|
THERE ARE AT LEAST A COUPLE OF DIFFERENT THINGS THAT COULD BE SAID FOR EACH PHASE. |
|
METAPHASE
|
|
|
ANAPHASE
|
|
|
TELOPHASE
|
7. Give three different, specific functions in the cell for:
| MICROFILAMENTS | MICROTUBULES |
| Cytoskeleton element. Produces cell cortex (kind of same thing) |
Cytoskeleton element (both of these can be) |
| Involved in extensions / withdrawals of the cell membrane | Move materials around inside of cell. Spindle fibers position & separate chromosomes |
| Various types of movement - inside cell, muscle contraction, etc. | Movement core of cilia or flagella; there are a couple more, too... |
BONUS QUESTIONS. Answer as many or as few as you wish. You can't lose points on the rest of the exam by getting these wrong. Partial credit is possible.
Sorry, Bonuses come from being in class and absorbing the implication & connections of the material - no key here.
What sorts of non-photosynthetic uses do plants have for carotenoids? Three Points each.
How / why did Gregor Mendel wind up doing his work with pea plants? Four Points.
For Three Points each, which lines of medical research are interested in telomeres, and for Five
Points each, how do telomeres figure into that line of research?
How does an antibiotic you're given today lead to a antibiotic resistance in a disease bacterium
you pick up a year later? Six Points.
It's fairly typical for a sperm tail to drop off during fertilization. What potential problem is this
thought to avoid? Four Points.
In what sorts of situations are organisms
benefitted by alternation of generations?
Four Points each (there's more than one).
Under what genetic conditions should a
color-blind son be born to a color-blind
father and non color-blind mother? Four
Points.