2250 - Principles of Genetics - Dr. Carr
Sample exam questions (for Midterms I & II, & Final Exam)
are intended to show the STYLE
of questions that MAY
be asked on exams, NOT the specific questions
that will be asked.
For all exams, you will be given a sheet with the Universal Genetic Code: it is therefore not necessary to memorize the genetic code.
I. MOLECULAR BIOLOGY: For each question, indicate in the space provided the LETTER of the ONE response that best answers the question.
In double-stranded RNA
regions, the bonds that hold complementary nucleotides
together are described as
A. ionic B. covalent C. hydrophobic D. hydrogen E. hydrophilic
The teritary structure of protein is determined by
A. beta sheets B. hydrogen bonds C. disulfide bonds D. alpha helices E. subunit arrangement
______ The active site of an
enzyme is most likely
to be composed of amino acids with the following
A. Polar & Hydrophobic B. Polar & Hydrophilic C. Non-polar & Hydrophobic D. Non-polar & Hydrophilic
Semi-conservative DNA replication was demonstrated by
Watson & Crick B. Meselson &
Stahl C. Hershey &
Chase D. Luria & Delbruck
E. Penn & Teller
II. MOLECULAR GENETICS. Each of the following five statements contains a basic misconception about genetics. In not more than three grammatically complete sentences, identify and correct the error. Do NOT exceed the space provided. Do NOT draw diagrams.
Ex.: "Because it has higher energy, gamma radiation is always more mutagenic than alpha radiation."
Sample answer: Gamma radiation is more
energetic than alpha, but that energy is dispersed over a
much longer path length, so it has a lower linear energy
transfer (LET) than alpha radiation.
The higher LET of alpha radiation means that its lower energy will be dispersed over a very short path.
If the energy is released within the nucleus of a single cell near a chromosome, it will be highly mutagenic.
eyes (B) are dominant to blue eyes (b). Both of my parents
have brown eyes, but I have blue eyes. Since eye colour is
genetic, I must be adopted."
Sample answer: Eye colour is likely a
polygenic trait (with multiple genes involved), so its
inheritance is not that simple.
Even if it were a simple Mendelian trait, your parents might both be Bb heterozygotes for brown eyes, and you could be a blue-eyed bb homozygote with blue eyes.
Ex.: "DNA probes
anneal to particular SNPs and are responsible for genetic
Ex.: "Met- mutants are caused by a defect of methionine that block its synthesis."
Ex.: "Most people do not have Cystic Fibrosis because
they do not have the gene for Cystic Fibrosis."
the template strand of a piece of DNA reads 3'
- AAAAAATTT - 5', its protein product will read:
A. H3N - F F K - COOH B. HOOC - F K K - NH3 C. H3N - K F F - COOH D. HOOC - K K F - NH3
III. MENDELIAN GENETICS. For each question, indicate in the
space provided the LETTER of the ONE response that best answers
______ A woman is heterozygous for an X-linked recessive allele that causes night-blindness. If she marries a man with night-blindness, what proportions of her female & male offspring will carry the night-blindness allele?
A) all, none B) all, half C) half, half D) half, none E) none, half F) none, all
______ In Trufula trees, the locus for leaf colour has three alleles: R (red), G (green), and B (brown). R is dominant to G, G is dominant to B. In the progeny of the cross BR x BG, what fraction will be brown ?
A) All B) 3/4 C) 1/2 D) 1/4 E) 0
______ Two individuals heterozygous for semi-dominant traits
at four loci are crossed: how many F2 genotypes are
A) 4 B) 9 C) 16 D) 27 E) 32 F) 64 G) 81
IV. GENETIC STRUCTURES: The numbers in the left-hand
column refer to structures on the right. For each numbered
structure, write the letter of the correct term [see example].
Several letters are not used; none is used more than once.
The following DNA is part of a gene that
codes for a polypeptide of at least seven amino acids:
3' caattgattagtcagtcaattgat 5'
5' gttaactaatcagtcagttaacta 3'
i. Which strand includes an Open Reading Frame? Top (T) or Bottom (B) [2 pts]
ii. Which DNA strand is the sense strand? Top (T) or
Bottom (B) [2
iii. Give the mRNA sequence that would be transcribed from this gene; label the 5' & 3' ends. [3 pts]
iv. Give the seven amino acids that would be translated from the correct message; label the C & N ends. [5 pts]
ANALYSIS: Given the pedigree shown, which of
the six modes of inheritance are
possible? Which is most likely?
What observations would change this?
TRIHYBRID THREE-POINT TEST
CROSS: From the following recombination data,
draw a physical map to indicate the correct order and
distances between loci.
VIII. RESTRICTION MAPPING: From the following fragment size data, draw a restriction map. Label the sites, provide a scale. [10 pts possible]
Watson & Crick received
the Nobel Prize in what year?
(a) 1953 (b) 1962 (c) 1973
Transcription proceeds in which of the following directions (a) 3' 1' (b) 2' 4' (c) 3' 5' (d) 4' 6' (e) 5' 3'
Which of the following amino
acids is/are non-polar?
Draw the structure of Deoxyadenosine monophosphate.
Outline the process of
What are the clues for sex-linked inheritance?
How many introns are present in the chicken ovalbumin gene? (a) 4 (b) 5 (c) 6 (d)
7 (e) more than 7
Text material © 2013 by Steven M. Carr