BIOLOGY 101 – SECTIONS 4015, 4016, 4023, 4024
PROFESSOR ALEX IMHOLTZ
EXAM 4 - FRIDAY 14 DECEMBER 2001
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KEY POINTS:
 THIS EXAM IS WORTH 100 POINTS. THERE ARE 30 MULTIPLE CHOICE
QUESTIONS, EACH WORTH 2.5 POINTS. THERE ARE ALSO 7 SHORT
ANSWER QUESTIONS, EACH WORTH 5 POINTS; CHOOSE 5 OF THE SHORT
ANSWER QUESTIONS.
 BUDGET YOUR TIME. SAVE THE HARD QUESTIONS FOR THE END.
 AS ALWAYS, BE SMART AND THINK! TRY AND ELIMINATE THOSE
ANSWERS THAT YOU KNOW ARE WRONG. PAY ATTENTION TO ANY
LIMITING ADJETIVES AND ADVERBS.
 DON’T GET CONFUSED. YOU KNOW THIS STUFF!
And now I’m glad I didn’t know
the way it would all end,
the way it would all go.
Our lives are better left to chance.
I could’ve missed the pain,
but then I’d have missed the dance.
- Garth Brooks, The Dance
MULTIPLE CHOICE – SELECT THE BEST ANSWER!
1.
There’s a structure in your brain called the habenula. The cells
that make up the habenula were undoubtedly created by the
process of:
a.
Meiosis I
b.
Meiosis II
c.
Interphase
d.
Mitosis
e.
Karyokinesis
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 1 of 9
2.
Gametes:
a.
b.
c.
d.
e.
Have a diploid number of chromosomes
Were created via mitosis
Have a haploid number of chromosomes
A and b are both correct
B and c are both correct
3.
A cell that
a.
b.
c.
d.
e.
is not dividing is said to be in:
Prophase
Interphase
M phase
Homeostasis
None of the above
4.
The structure connecting 2 sister chromatids is the:
a.
Centromere
b.
Centrosome
c.
Chromomere
d.
Centriole
e.
Chromatin
5.
The drug Taxol inhibits the formation of the spindle. One can
thus assume that:
a.
Taxol inhibits mitosis but not meiosis
b.
Taxol inhibits meiosis but not mitosis
c.
Taxol inhibits both mitosis and meiosis
d.
Taxol does not affect either mitosis or meiosis
e.
Taxol inhibits meiosis but not sperm or egg
production
6.
Which of the following does NOT belong?
a.
Skin cells
b.
DNA replication
c.
Mitosis
d.
Crossing-over
e.
Cytokinesis
7.
The number of sex chromosomes in a diploid cell is:
a.
44
b.
22
c.
2
d.
1
e.
None of the above
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 2 of 9
8.
Which of the following is TRUE?
a.
TKILLER cells are typically haploid
b.
TSUPPRESSOR cells are made via meiosis
c.
Red blood cells are made via meiosis
d.
2 THELPER daughter cells would NOT be genetically
identical
e.
Plasma cells are made via mitosis
9.
As a result of ____________________, the genetic variability of
the gametes is increased.
a.
Mitotic Prophase
b.
Crossing-over during Metaphase II
c.
Crossing-over during Prophase I
d.
Homologous reassortment during interphase
e.
Polygenic inheritance
10.
You are delighted to receive a microscope for Christmas. You
immediately decide to look at some dividing cells! How would
you know whether a cell was in metaphase of mitosis or
metaphase I of meiosis?
a.
If the chromosomes line up in homologous pairs, it’s
mitotic metaphase
b.
If the chromosomes line up in homologous pairs, it’s
metaphase I of meiosis
c.
If the DNA has replicated, it’s mitotic metaphase
d.
If the DNA has replicated, it’s metaphase I of meiosis
e.
It simply cannot be determined
11.
Duchenne’s muscular dystrophy (a disease in which skeletal
muscles progressively weaken) is an X-linked disorder. Which of
the following is TRUE?
a.
Males are less likely to be have Duchenne’s muscular
dystrophy than females
b.
Both males and females are equally likely to have
Duchenne’s muscular dystrophy
c.
Males are more likely than females to have
Duchenne’s muscular dystrophy
d.
Because it is X-linked, it is impossible for males to
have Duchenne’s muscular dystrophy
e.
None of the above are true
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 3 of 9
12.
A ______________ is a particular series of nucleotides in DNA
that collectively code for the synthesis of a _______________.
a.
Gene;
Protein
b.
Gene;
Lipid
c.
mRNA;
Gene
d.
Protein;
Gene
e.
Gene;
Allele
13.
Given the following DNA sequence:
T-T-T-T-C-C-G
What is the complementary RNA sequence?
a.
A-A-A-A-G-G-C
b.
U-U-U-U-G-G-C
c.
A-A-A-A-C-C-G
d.
U-U-U-U-C-C-G
e.
None of the above
14.
Huntington’s disease is a dominant disorder. Suppose that both
Larry and Beatrice are heterozygous for the disease. Of their 8
children, statistically, how many would be expected to NOT have
Huntington’s disease?
a.
1
b.
2
c.
4
d.
6
e.
8
15.
Consider the following events of protein synthesis and then
choose the option that has placed them in the correct
chronological order.
1.
mRNA transcribed
2.
DNA double helix unwinds
3.
mRNA binds to ribosome
4.
Ribosome bonds amino acids together
5.
tRNA delivers amino acids to ribosomes
6.
mRNA leaves nucleus
7.
Polypeptide chain completed
a.
b.
c.
d.
e.
2-1-3-4-5-6-7
7-6-5-4-3-2-1
1-3-5-7-2-4-6
2-1-6-3-5-4-7
1-3-4-6-2-5-7
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 4 of 9
16.
My DNA is different from your DNA in:
a.
The types of nucleotides it contains
b.
The number of nucleotides it contains
c.
The sequence of the nucleotides
d.
The bonding of the nucleotide pairs
e.
None of the above. Human DNA does not vary from
individual to individual
17.
Which of the following does NOT belong?
a.
Uracil
b.
mRNA
c.
tRNA
d.
Thymine
e.
Cytosine
18.
Genetic engineering can be used to:
a.
Produce healthier foods
b.
Produce human proteins for medical treatment
c.
Clean up pollution
d.
Make plants pest resistant
e.
All of the above
19.
A cross between a black Labrador retriever (a type of large dog)
and a yellow Labrador retriever produces “chocolate” (brown)
offspring. The simplest genetic explanation for this is:
a.
Dominant/Recessive inheritance
b.
Codominance
c.
Polygenic inheritance
d.
Multiple alleles
e.
Incomplete dominance
20.
Cystic fibrosis is a recessive disorder. Monica is homozygous
recessive for cystic fibrosis while Lonny is heterozygous. If
Lonny and Monica have a child…
a.
It is NOT possible for the child to have cystic fibrosis
b.
There is a 50% chance that the child will NOT have
cystic fibrosis
c.
There is a 100% chance that the child will have
cystic fibrosis
d.
It cannot be determined whether or not the child will
have cystic fibrosis
e.
None of the above are correct
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 5 of 9
21.
Consider the following statement. The environment cannot have
an effect on an organism’s genotype or its phenotype.
a.
This statement is TRUE
b.
This statement is FALSE because environment can
have an effect on phenotype and genotype
c.
This statement is FALSE because environment can
have an effect on phenotype ONLY
d.
This statement is FALSE because environment can
have an effect on genotype ONLY
e.
It cannot be determined whether this statement is
true or false
22.
Nondisjunction can:
a.
Occur during meiosis I
b.
Occur during meiosis II
c.
Result in gametes with too many chromosomes
d.
Result in gametes with too few chromosomes
e.
All of the above
23.
The correct
a.
b.
c.
d.
e.
24.
Cells from your cheek would NOT contain sex chromosomes.
a.
This statement is TRUE
b.
This statement is FALSE
25.
In, humans, the number of sex chromosomes in a haploid cell is
EXACTLY ½ the number of sex chromosomes in a diploid cell.
a.
This statement is TRUE
b.
This statement is FALSE
sequence of events in mitosis is:
Anaphase, Metaphase, Prophase, Telophase
Prophase, Metaphase, Telophase, Anaphase
Prophase, Metaphase, Anaphase, Telophase
Prophase, Anaphase, Metaphase, Telophase
Metaphase, Prophase, Anaphase, Telophase
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 6 of 9
26.
27.
Having unattached ear lobes is a dominant trait (E). A male
whose genotype was E? had a child with a female whose
genotype is ee.
a.
It’s theoretically possible that this child could have
unattached ear lobes
b.
It’s theoretically possible that this child could have
attached ear lobes
c.
It cannot be determined whether it is possible for the
child to have either attached or unattached earlobes
d.
A and b are both correct
e.
None of the above are correct
If a DNA triplet is ACT, then:
a.
The mRNA codon will be
anticodon will be ACU
b.
The mRNA codon will be
will be UGA
c.
The mRNA codon will be
will be ACT
d.
The mRNA codon will be
will be TGA
e.
None of the above
UGA and the tRNA
ACU and the tRNA anticodon
TGA and the tRNA anticodon
ACT and the tRNA anticodon
28.
There are 20 different types of amino acids used in protein
synthesis. Thus, there are _____ different types of tRNA.
a.
5
b.
10
c.
20
d.
40
e.
100
29.
Which of the following organelles plays the smallest role in
protein synthesis?
a.
Ribosome
b.
Nucleus
c.
Golgi Apparatus
d.
Endoplasmic reticulum
e.
Chloroplast
30.
The human genome has been sequenced.
a.
This statement is TRUE
b.
This statement is FALSE
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 7 of 9
SHORT ANSWER: THERE ARE 7 QUESTIONS. ANSWER ONLY 5 OF THEM.
EACH IS WORTH 5 POINTS. IF YOU ANSWER MORE THAN 5, ONLY THE 1ST 5
WILL BE GRADED! USE PROPER AND GRAMMAR AND SPELLING AND PLEASE
MAKE IT LEGIBLE. BE CONCISE AND ACCURATE. IF NECESSARY, SHOW YOUR
WORK!
1. Which do you suppose would be more harmful. A mutation
that changed the nucleotide sequence of an mRNA
molecule, or a mutation that changed the nucleotide
sequence of a DNA molecule?
A mutation in DNA would be more harmful because it could
cause the synthesis of multiple nonfunctional proteins,
whereas a mutation in mRNA would be less harmful because it
would only result in very few nonfunctional proteins.
2. All body cells have the same DNA complement yet all body
cells do NOT contain the same proteins. How is this
possible?
Because, not every cell activates the same genes. Different
cells transcribe different genes and synthesize different
proteins.
3. What do transfer RNA and messenger RNA have in
common? How do they differ? (Consider both structure
and function)
They are both nucleic acids involved in protein synthesis. Both
are made up of the pentose sugar, ribose, a phosphate group,
and a nitrogenous base (adenine, cytosine, guanine, uracil).
Both are made in the nucleus and both are single stranded.
They differ in their length (mRNA are, on average, longer) and
function. TRNA function to transport amino acids to the
ribosomes while mRNA carry the instructions for the particular
polypeptide to the ribosomes. For even more
differences/similarities, consult your text.
4. Consider a bacterial gene that is approximately 2100
nucleotides long.
 Approximately how many amino acids would this gene
code for? 700
 How many mRNA molecules will probably be
transcribed from this gene? 1
 How many proteins will probably be made from this
gene? 1
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 8 of 9
5. Can an X-linked trait be passed from father to son? Explain
why/why not? NO. Males have a Y chromosome. Since
females do not have a Y, sons must receive the Y from their
father. Thus they receive the X from the mom and any Xlinked traits from the mom – NOT FROM THE DAD.
6. What is the probability that a mating between 2 carriers
(individuals who have the allele but are phenotypically
normal) will produce an offspring with a recessively
inherited disorder? 1 in 4
7. Tallness is a dominant trait in pea plants. Suppose a tall
pea plant is crossed with a recessive dwarf pea plant. What
will the phenotypic and genotypic ratios of the offspring be
a.
if the tall plant was TT?
Genotypes–100% Tt
Phenotype–100% Tall
b.
if the tall plant was Tt?
Genotypes–50% Tt, 50% tt Phenotype–50% tall, 50% dwarf
BONUS QUESTION: IF YOU HAD A DNA MOLECULE THAT WAS 15% ADENINE,
WHAT PERCENTAGE OF IT WAS GUANINE? (YOU MUST SHOW YOUR WORK TO
RECEIVE ANY CREDIT). 4 POINTS.
15% ADENINE MEANS 15% THYMINE. THUS, IT’S 70% CYTOSINE AND
GUANINE. SO, GUANINE MUST BE 35%.
IMHOLTZ – BIOLOGY 101 – EXAM 4 – PAGE 9 of 9