Grade 12 Biology: Molecular Genetics
Review Questions
The unit test will be composed of three sections.
Part A: Study Notes. You will create study notes to completely and correctly
answer ALL of the review questions. You will submit your study sheets before the
test. (10 marks)
Part B: Short Answer Questions (25-30 marks).
Part C: Critical Thinking Questions (10-15 marks)
Part B: Short Answer Questions
1. Define heterozygous/homozygous/phenotype/genotype/dominant/recessive.
2. Why should you make study notes every night?
3. What is a Punnett square? How is it used?
4. How is DNA used in crime scene investigations?
a. What is the structure of DNA? What is a nucleotide?
b. How does DNA replicate? Compare the formation of leading and lagging strands.
c. What is PCR (polymerase chain reaction)? How has it changed crime scene
investigations?
d. What is DNA fingerprinting?
5. How is DNA different in different species?
6. How does DNA determine how you look?
a. What is transcription?
b. What is translation?
c. What is the role of DNA, mRNA and tRNA and amino acids in protein synthesis?
d. What is the amino acid sequence of the protein that would be synthesized after
transcription and translation of the following piece of template strand DNA?
5'
3'
_____________________
TCATGCGCAACA
* or some question similar to this one!!
Codon
AGU
ACG
CGU
UGU
UGC
GCA
UGA
codon translations
amino acid
Ser
Thr
Arg
Cys
Cys
Ala
stop
7. How do mutations affect living organisms?
a. What can cause cancer?
b. How are mutations caused by substitution, deletion, addition, inversions and/or
jumping genes?
8. What is genetic engineering?
a. Should we label genetically modified food?
b. Should we produce and eat genetically modified food?
Part C: Critical Thinking Questions
1. a. How did you think scientific discoveries were made BEFORE you started this course?
b. How have your views changed since you learned about the discovery of PCR or DNA
fingerprinting?
2. Initial reluctance among the scientific community to accept that DNA was the molecule
forming genes (carrying a great deal of information) stemmed to some extent from the
knowledge that DNA was a relatively simple molecule, made up of only four
nucleotides—adenine, cytosine, guanine, and thymine. Briefly explain how DNA is
capable of encoding a great deal of information, in spite of its apparently simple
structure.
3. DNA and protein are functionally linked because genes in the DNA code for protein.
How do the roles of DNA and protein in the life of the cell differ?
4. How does DNA determine how you look?
5. Please comment on the following statement: You are your enzymes
6. The view has been expressed that there is really no difference between producing new
plant and animal varieties by genetic engineering and producing new varieties by
traditional selective breeding methods and hybridization. Do you agree? Explain
7. Objections to drugs and other therapeutic agents produced by genetically modified
organisms are rarely heard, but objections to food produced by genetically modified
organisms are often voiced. How do you explain this?
8. Peter Parker was transformed into Spiderman after being bitten by a genetically modified
spider. Is this possible? Why? Why not?