DNA Structure, Replication and Protein Synthesis

Student Name: ______

DNA Structure, Replication and Protein Synthesis

Q1

(a) Insert the most appropriate words in each of the following spaces:

A section of DNA that causes the production of a protein is called a ______. Sections of DNA that do not code for a particular protein are called ______. The protein ______is responsible for holding the DNA in its highly coiled state. DNA is made up of units called ______. A sequence of three bases is referred to as a ______.

(b) The diagram shows a representation of a section of a DNA molecule. What is represented by each of the letters A, C, D, G, P and T?

A ______

C ______

D ______

G ______

P ______

T ______

Identify the two purine bases and the two pyramidine bases.

Purine bases ______

Pyramidine bases ______

What name is given to the shape of the DNA molecule? ______

(d) State three differences between DNA and RNA.

1 ______

2 ______

3 ______

(e) Write down the sequence of RNA bases that is complementary to the following DNA sequences

TATCGGCA ______ATGCATA ______

Q2 Give a reason for each of the following steps when isolating DNA from a plant tissue.

Adding salt ______

______

Cooling the mixture after exactly 15 minutes ______

______

Filtering the mixture after blending ______

______

Adding protease enzyme ______

______

Adding cold ethanol ______

______

Q3 What are the three main stages of protein synthesis called?

1 ______2 ______3 ______

Outline a use for each of the following in proteins synthesis:

RNA Polymerase ______

tRNA ______

mRNA ______

rRNA ______

Start codon ______

Anti-codon ______

Amino acid ______

Q4 During what stage of the cell cycle does DNA replication take place? ______

Why is it necessary for DNA to make copies of itself? ______

______

Name the part of a double stranded chromosome to which spindle fibres attach during cell division ______

Outline the process of DNA replication in four stages

1 ______

2 ______

3 ______

4 ______