10 points
DNA – Replication, Transcription and Translation
Bio 101- Section ________
Name _________________________________
1. A sequence of a short segment of DNA is shown. Write the base sequence in the complementary strand
and label all ends with the appropriate prime number (the first prime number is indicated).
3’
A A T C G T A A G C T _’
2. Following diagram represents the flow of genetic information in protein synthesis
DNA
What term is indicated for the process of DNA creating mRNA? _____________________
mRNA
What is the appropriate term for the process indicated by creating a protein from mRNA?
_________________________________
Protein
3. Nucleotide sequence of a short piece of DNA is given below. Write the codon sequence of the mRNA
strand, RNA sequence and the amino acid chain coded for by this DNA segment. (Use the genetic code in the
text book. Standard three letter abbreviations for amino acids found in your textbook appendix are appropriate.)
DNA
TAC
GTT
GAC
CTT
CGA
CAG
ATT
mRNA
tRNA ________________________________________________________________________________
Amino acid
4.
Give the amino acid sequence if the DNA sequence in question 3 has acquired a mutation. (indicated in bold)
DNA
TAC
GTG
GAC
CTT
CGA
CAG
ATT
mRNA
Amino acid
5. Circle the amino acid(s) above that is/are different in the mutated protein from the normal protein.
6. Now a different mutation has occurred to the same original DNA. Write the new mRNA and amino acid sequences
that will result from this mutated DNA.
DNA
TAC
GT
GAC
CTT
CGA
CAG
ATT
mRNA
Amino acid
7. A tRNA molecule has the anticodon GCC. Which amino acid is transferred by this tRNA to the ribosome?
A) Alanine (Ala)
D) Serine (Ser)
B) Arginine (Arg)
E) Valine (Val)
C) Leucine (Leu)
8. A hypothetical cell containing a single chromosome is placed in a medium containing radioactive
phosphate so that any new DNA strands formed by DNA replication will be radioactive. The cell
replicates its DNA and divides. Then the daughter cells (still in the radioactive medium) replicate their
DNA and divide, and a total of four cells are present. Sketch the DNA molecules in all four cells,
showing a normal (nonradioactive) DNA strand as a solid line and a radioactive DNA strand as a dashed
line.
9. Name the three enzymes involved in DNA replication and explain each role as replication proceeds.
A)
B)
C)
10. What is an Okazaki fragment and what does it have to do with DNA replication? Explain clearly how it is
created.