SBI4U Multiple Choice questions: Unit 4  ANSWER KEY
1) Hershey and Chase used radioactive sulfur in the protein coat to figure out
whether it was the DNA or the protein coat that entered the bacteria. Why
did they use radioactive sulfur instead of radioactive phosphate?
a) Sulfur is highly reactive
b) The protein coat cannot bond with radioactive phosphate
c) It was their favourite chemical
d) The amino acids in the protein coat contain sulfur
2) Rosalind Franklin’s research helped discover what about DNA?
a) How many genes were in it
b) DNA’s helical structure
c) The length between the strands
d) That it was inside the nucleus of the cell
e) That it was 7.84 nm away from the cell membrane
3) What was the name of Chargaff’s findings?
a) Chargaff’s nucleotides
b) Complimentary bases
c) Chargaff’s rules
d) A,T,G,C rules
e) Purine and Pyrimidine
4) What organism did Friedrich Miescher work with specifically?
a) Red blood cells
b) Humans
c) White blood cells
d) Platelets
e) None of the above
5) Nucleotides consist of a 5’ carbon sugar with certain items attached to their
1’ carbon and to their 5’ carbon. Which molecules attach to the 1’ carbon and
the 5’ carbon respectively:
a) Deoxyribose and ribose
b) Hydroxyl and a phosphate group
c) Thymine and adenine
d) Nitrogenous base and a phosphate group
e) Glycosyl and a Phosphodiester bond
6) The phosphate group is attached to the 5’ carbon by a:
a) Glycosyl bond
b) Phosphodiester bond
c) Ester bond
d) Hydrogen bond
e) None of the above
7) 3.4nm is the measurement of one complete turn of the DNA helix. How many
base pairs are there in one complete turn?
a) 2
b) 10
c) 340
d) 20
e) 3.4
8) Two strands of DNA are said to be:
a) Parallel
b) Perpendicular
c) Anti-parallel
d) Anti-perpendicular
e) Non of the above
9) What are Chargaff’s rules?
a) A,T,C,G are all equal in terms of composition in the DNA helix
b) DNA is double stranded
c) A=T and G=C in terms of composition in the DNA helix
d) The amount of purines is always equal to the amount of pyrimidine’s
in the DNA helix
e) RNA is single stranded
10)Which of the following was ONE of Griffith’s experiments?
a) He injected the mice with dead S-strain and the mice died
b) He injected the mice with dead R-strain and the mice lived
c) He injected the mice with live S-strain and the mice lives
d) He injected the mice with live S-strain and dead R-strain, and the mice
lived
e) He injected the mice with dead S-strain and live R-strain, and the mice
died
11)Although Franklin did not get the recognition she deserved for her discovery,
whom else did she work with for her research?
a) Friedrich, Crick, Mendel
b) Wilkins, Watson
c) Crick, Watson, Avery
d) Wilkins, Watson, Crick
e) Crick
12)How did Friedrich Miescher contribute to the discovery of DNA?
a) He discovered that each organism has its own genes
b) He discovered that DNA is a helical structure
c) He discovered transposition, which is the jumping of genes
d) He isolated the material that contained DNA for the very first time
e) Both a and c
13) Mclintock discovered ‘jumping genes’ called transposons. These
transposons:
a) Turn on/off gene expression
b) Can lead to variation in phenotypes
c) Only operate in plants
d) A and c
e) A and b
14) If a strand of DNA has 1.5 billion complete turns, how long is it and how
many nucleotides does it contain?
a) 5.1m, 1.5 X 1010
b) 5.1m, 5.1 X 109
c) 4.4m, 1.5 X 1010
d) 4.4m, 6.2 X 109
e) 6.2m, 5.1 X 109
15)Which is correct about one complete turn in a strand of DNA?
a) It is 100 nucleotides long
b) It is 15 nucleotides long
c) It is 10nm long
d) It is 3.4nm long
e) Non of the above
16)When a bacteriophage (a virus) attacks a bacterium, it injects its hereditary
information inside. Based on this information, what part of the bacteriophage
contains the hereditary information that enters the bacteria?
a) DNA
b) Protein coat
c) Cilia
d) Flagellum
17)Which of the following is correct:
a) A & T have 3 hydrogen bonds, C & G have 2 hydrogen bonds
b) A & T have 2 hydrogen bonds, C & G have 3 hydrogen bonds
c) Purines have 1 hydrogen bond, pyrimidine’s have 2 hydrogen bonds
d) Pyrimidine’s have 1 carbon ring, purines have 2 carbon rings
18)A DNA molecule in a particular chromosome I 50nm long. How many
nucleotide pairs does this molecule have?
a) 1.5 X 10-8 base pairs
b) 1.5 X 10-7 base pairs
c) 1.7 X 107 base pairs
d) 15000 base pairs
e) 1.5 X 108 base pairs
19) What organism did Barbara McClintock work with?
a) Fruit flies
b) Mice
c) Corn
d) Peas
e) All of the above
20)Even though a pyrimidine and a purine together would constitute the desired
diameter within the DNA molecules, why would the molecule be unstable?
a) Two purines are needed to bond together
b) Lack of covalent bonding
c) Two pyrimidine’s are needed t bond together
d) Lack of hydrogen bonding
e) Hydrogen bonding is too strong
21)Which of the following statements are false?
a) A purine is always bonded to a pyrimidine
b) Complementary base pairing is when A & T bond together and C & G
bond together
c) Under some circumstances, A & G and C & T can bond together
d) Base pairing consists of antiparallel strands of nucleotides
22)Griffith worked with a bacteria for:
a) Stomach flu
b) Pneumonia
c) Tuberculosis
d) Bronchitis
e) Strep throat
23)Which of the following is a sugar exclusive to DNA?
a) Ribose
b) Glucose
c) Deoxyribose
d) Adenine
e) Hydroxyl
24)Which scientist(s) helped Watson and Crick with the discovery of the double
helix model?
a) Linus Pauling
b) Rosalind Franklin
c) Gregor Mendel
d) Maurice Wilkins
e) Both b and c