General Genetics
Exam 1
Name ___________________________
Multiple Choice (Choose the one best answer) (1 pt.)
1. _____ Starting with a P generation with the following genotypes (AABB x aabb). Based on classical Mendelian
inheritance, what is the expected phenotypic ratio observed among the F2 progeny?
a) 9:3:3:1
b) 1:2:1
c) 3:1
d) 1:1
e) 1:1:1:1
2. _____ The technique used to separate molecules on the basis of their different rates of movement in an electric field is
known as ____.
a)
b)
c)
d)
e)
gel electrophoresis
gradient centrifugation
ultracentrifugation
Southern hybridization
PCR
3. _____ In a cross of a yellow hybrid pea with a true breeding yellow parent (Gg x GG), what genotypic proportions would
be observed in the offspring?
a)
b)
c)
d)
Half heterozygous, half homozygous dominant
Half yellow, half green
All heterozygous
All yellow
4. _____ Having an attached earlobe results from an autosomal recessive allele designated a. Two parents with unattached
earlobes have a child with attached earlobes. What is the probability that their next child will have attached earlobes? What is
the probability that the next child will be a girl with attached earlobes?
a) 1/2; 1/4
b) 1/4; 1/2
c) 1/4; 1/8
d) 1/8; 1/4
5. _____ Start with a P generation with the following genotypes (AABB x aabb). I f A = long fur and a = short fur and B = Long tail
and b = short tail, what phenotypic class would be observed in the highest proportion in the F2 generation?
a)
b)
c)
d)
long fur, short tail
long fur, long tail
short fur, short tail
short fur, long tail
6. _____ The process of producing a RNA polymer from a DNA template is called __.
a)
b)
c)
d)
replication
transcription
translation
duplication
7. _____ What is the probability that on three flips of a coin, heads will occur on two flips and tails on one?
a) 1/4
b) 1/2
c) 3/16
d) 3/8
8. _____ Starting with a cross between parents (P generation) with BB and bb genotypes, the proportion of heterozygotes in
the F2 progeny will be ___.
a)
b)
c)
d)
e)
1/8
1/4
1/3
1/2
All heterozygotes
9. _____ In crosses involving two different unlinked traits, the ratio 9:3:3:1 indicates ___.
a)
b)
c)
d)
Codominance
Independent assortment
Intermediate dominance
Three alleles for each trait
10. _____ The chemical bonds in DNA by which the sugar components of adjacent nucleotides are linked through the
phosphate groups are called ____ bonds.
a)
b)
c)
d)
e)
phosphodiester
hydrogen
hydrophobic
hydrophilic
ionic
11. _____ What genotype is present most often among the progeny (F2) of a dihybrid cross (AaBb X AaBb)?
a) AaBb
b) AABb
c) AABB
d) aabb
e) AAbb
12. _____ Which of the following is not an essential attribute that a biological molecule would need to be a useful genetic
material?
a) It must carry all of the information needed to direct the specific organization and metabolic activities of the
cell
b) It must replicate accurately so that the information it contains is precisely inherited by the daughter cells
c) It must be capable of undergoing occasional mutations, such that the information it carries is altered in a
heritable way
d) It must have highly repetitive DNA sequences.
e) All are essential attributes of useful genetic material.
13. _____ In a F1 dihybrid cross (WwGg X WwGg) where W = round, w = wrinkled, G = yellow and g = green, what is the
probability of obtaining an individual that is round, green and true-breeding for both traits?
a) 1/16
b) 1/2
c) 9/16
d) 3/16
e) 1/4
14. _____ The basic structure of a nucleotide includes the following components:
a)
b)
c)
d)
e)
amino acids
tryptophan and leucine
base, sugar, phosphate
mRNA, rRNA, tRNA
phosphorous and sulfur
15. _____ The sequence of one strand of DNA is 5' - GATCGA - 3'. The sequence of the complementary strand would be
a)
b)
c)
d)
e)
5' - AGCTAG - 3'
5' - TCGATC - 3'
5' - CTAGCT - 3'
5' - GCTAGC - 3'
5' - GATCGA - 3'
16. _____ What ratios (genotypic or phenotypic) typically result from crosses dealing with a single genetic locus?
a)
b)
c)
d)
e)
9:3:3:1, 1:2:1
1:1:1:1, 1:4:6:4:1
3:1, 1:1, 1:2:1
9:7, 12:3:1
15:1, 1:2
17. _____ Probabilities are calculated using the addition rule when they ___.
a)
b)
c)
d)
are equally likely
are independent
are mutually exclusive
occur disproportionately
18. _____ Mr. and Mrs. Granger are "normal" Muggles (non-magical) but their daughter Hermione has magical powers. They
think this is pretty cool and would like to have another child with magical powers. Assuming that magical powers is a
classical Mendelian trait, what is the probability that their next child will be another girl with magical powers?
a) 1/2
b) 1/4
c) 1/8
d) 3/4
e) 3/8
19. _____ Mr. and Mrs. Granger from the previous question soon learn that Mrs. Granger is pregnant with dizygotic twins.
What is the probability that one of them will have magical powers?
a) 1/2
b) 1/4
c) 1/8
d) 1/16
e) 1/64
20. _____ Considering the structure of double stranded DNA, what kinds of bonds hold one complementary strand to the
other?
a)
b)
c)
d)
ionic
covalent
Van der Waals
hydrogen
21. _____ Probabilities are calculated using the multiplication rule when they ___.
a)
b)
c)
d)
Are equally likely
Are independent
Are mutually exclusive
Occur disproportionately
22. _____ Genotype is to DNA as phenotype is to
a)
b)
c)
d)
e)
Genotype
Proteins
Expressivity
RNA
Mutation
23. _____ A variety of rose can have white or red flowers and long or short thorns. A cross between red, short-thorned roses
and white, long-thorned roses produce all red, short-thorned roses. Using the gene symbols W for red, w for white, L for
short-thorned and l for long-thorned, what would be the genotype of a white, long-thorned rose?
a) WWLL
b) wwLL
c) wwll
d) not enough information
24. _____ In the previous question (question 23) how many different gametes will a white, long-thorned rose produce?
a) 1
b) 2
c) 4
d) 16
25. _____ In question 23, how many different gametes will the F1 roses produce?
a) 1
b) 2
c) 4
d) 8
26. _____ What would be the dimensions of a Punnett square for the cross Ww x ww?
a)
b)
c)
d)
4x4
2x2
2x1
1x1
27. _____ The Hershey and Chase experiment which offered evidence in support of DNA being the genetic material in
bacteriophage made use of the following labeled components
a)
b)
c)
d)
phosphorous and sulfur
nitrogen and oxygen
tritium
hydrogen
28. _____ Microbiologist who used Streptococcus pneumnia to demonstrated that DNA was the genetic material.
a)
b)
c)
d)
e)
Oswald Avery
Herbert Boyer
Rosalind Franklin
Barbara McClintock
James Watson
29. _____ The process of producing an amino acid polymer (polypeptide) from a RNA template is called __.
a)
b)
c)
d)
replication
transcription
translation
duplication
30. _____ In dihybrid crosses, the ratio 9:3:3:1 indicates ___.
a)
b)
c)
d)
Codominance
Independent assortment
Intermediate dominance
Three alleles for each trait
31. _____ Mendel's First Law, which explains the inheritance of contrasting traits in a monohybrid cross, describes the
process of ____.
a)
b)
c)
d)
e)
segregation
independent assortment
continuous variation
discontinuous variation
dominance or recessiveness
32. _____ What would be the dimensions of a Punnett Square depicting a dihybrid cross?
a)
b)
c)
d)
1x4
2x4
4x4
2 x 2.
33 _____ There are three different genotypes resulting from a monohybrid cross. How many different genotypes would there
be resulting from a dihybrid cross?
a)
b)
c)
d)
4
8
9
16
Short Answer (1 pt.)
34. Black coloration in cattle is dominant to brown. White patches are dominant to solid coloration. Black and white cattle
were crossed over several years producing mostly black and white progeny but also producing some brown and white, some
solid black and even some solid brown. What is the most probable genotype of each parent?
35. In the previous question (question 34) what is the expected phenotypic ratio for all the phenotypes?
36. In your own words, what is the meaning of the term allele?
37. In Dragon genetics the symbol G is for dark green skin color and g is for light green skin color, A is for a straight, pinted
tail and a is for a tail with an arrowhead structure at the end. In the cross GgAa x GgAa what fraction of the Dragons will be:
A) light green with straight, pointed tails?
B) dark green an arrowhead like structure at the end of their tails?
C) have an arrowhead like structure at the end of their tails?
D) light green in color?
38. What type of cross produces a 1:1:1:1 phenotypic ratio?
39. If one of the strands of a piece of DNA has the sequence 5'-GCTAGGACGCTATAGGGTAAC-3', what is the sequence
of the complementary strand? Label the termini as 5' or 3'.
40. Give one reason why the relationship between genes and traits is often complex.
41. A certain type of congenital deafness in humans is caused by a rare autosomal dominant gene. In a mating involving a
deaf man and a deaf woman, could all their children have normal hearing? Explain.
42. I have six sisters and one brother. My brother is the oldest and I am child number 6. What is the probability of parents
having 6 girls and 2 boys in the order I just described?
43. If the G + C content of a DNA molecule is 62%, what are the percentages of all four bases?
44. Synthesis of DNA is catalyzed by an enzyme called ____________________ and synthesis of RNA is catalyzed by an
enzyme known as _____________________.
45. Draw a Punnett square for the following cross: Bb x Bb
46. Draw a Punnett Square for the following cross: AaBb x AaBb. (4 pts)
47. In the pedigree to the right, what are the possible genotypes
of each of the individuals?
I-1
I-2
II-1
II-2
II-3
II-4
48. In the above pedigree, what is the probability that individual II-2 is heterozygous?
49. In the molecular pedigree below, what are the genotypes of the following individuals:
I-1
II-1
II-3
50. Draw in the band(s) you would expect to see for individual II-3.