8.1 The genetic code

Question 1

What is the flow of genetic information

Answer 1

DNA> RNA> Protein

Question 2

___________ transcibes DNA to produce an RNA transcript

Answer 2

RNA polymerase

Question 3

________ translates the mRNA sequence to synthesise a polypeptide

Answer 3

Ribosomes

Question 4

Experiments demonstrated that 3 nucleotides=

Answer 4

codon= 1 amino acid

Question 5

A gene’s nucleotide sequence is colinear with the _____________ of the encoded polypeptide

Answer 5

amino acid sequence

Question 6

Each nulceotide is part of only one _________

Answer 6

codon

Question 7

The beginining of a gene establishes a __________

Answer 7

reading frame

Question 8

Define reading frame

Answer 8

the grouping of three successive bases in a sequence of DNA that constitutes the codons for the amino acids encoded by the DNA.

Question 9

What does proflavin do

Answer 9

It inserts or deletes one nucleotife creading a frameshift mutation

Question 10

What is a frameshuft mutation

Answer 10

It is a mutation that causes a change in the reading frame of a DNA sequence. They result from insertions and deletions

Question 11

In vitro translation of synthetic mRNAs: (3)

Answer 11

1. Preparation of cellular extracts that allowed translation in a test tube
2. Developed techniques to synthesise artifical RNAs with known nucleotide sequence
3. Allowed synthesis of simple polypeptides

Question 12

What was used to crack the genetic code

Answer 12

The use of mRNAs and in vitro translation

Question 13

All but the simplest mRNAs leave some ___________

Answer 13

ambiguity

Question 14

What are the three stop codons

Answer 14

UAA, UGA, UAG

Question 15

What is the start codon

Answer 15

AUG

Question 16

What are the three ways mutations can be created?

Answer 16

Misense, nonsense and frameshift