Cell Bio - DNA Structure

Question 1

Describe the structure of DNA and explain its purpose

Answer 1

• Double stranded helix held together by complementary base pairs
• Carries the genetic information for making proteins. It is stored inside the nucleus of the cells in chromosomes

Question 2

State the four bases and their complementary base pairs

Answer 2

BASES
* Adenine
* Thymime
* Guanine
* Cytosine

COMPLEMENTARY BASES
* Adenine always pairs with Thymine
* Guanine always pairs with Cytosine

Question 3

Define the genetic code

Answer 3

It is the sequence of bases along a strand. This sequence determines the amino acid sequence in proteins.

Question 4

Define a gene

Answer 4

A gene is a section of DNA that codes for a protein

Question 5

What are the two strands in DNA held together by?

Answer 5

Weak hydrogen bonds

Question 6

What is a chromosome and how many pairs do humans have?

Answer 6

• DNA stored as long thin threads.
• 23 pairs (46 in total)

Question 7

What is the name of the hundreds of repeating units that make up DNA strands?

Answer 7

Nucleotide bases

Question 8

Describe how the code to make the protein insulin would differ from making the protein amylase

Answer 8

Diiferent proteins have a different order of bases