DNA structure and function

Question 1

What is a polynucleotide?

Answer 1

Lots of nucleotides joined together

Question 2

What is each DNA nucleotide made up from?

Answer 2

A pentose sugar, a phosphate group and a nitrogenous base

Question 3

What are the 2 DNA strands joined by?

Answer 3

Hydrogen bonds

Question 4

What does C stand for (base)?

Answer 4

Cytosine

Question 5

What does G stand for (base)?

Answer 5

Guanine

Question 6

What does T stand for (base)?

Answer 6

Thymine

Question 7

What does A stand for (base)?

Answer 7

Adenine

Question 8

What shape does DNA form?

Answer 8

A double helix

Question 9

What are genes?

Answer 9

Sections of DNA, found on chromosomes

Question 10

What do genes code for?

Answer 10

Amino acids which make up polypeptides

Question 11

If a section of DNA doesn’t code for an amino acid what do we call it?

Answer 11

Introns

Question 12

If a section of DNA does code for an amino acid what do we call it?

Answer 12

Exon

Question 13

What is a DNA triplet?

Answer 13

A sequence of 3 bases

Question 14

Do parts of DNA that repeat themselves over and over code for amino acids?

Answer 14

NO

Question 15

What does the order of the bases determine?

Answer 15

The order of the amino acids and therefore the type of polypeptide

Question 16

What is an allele?

Answer 16

A form of a gene

Question 17

What is a mutation?

Answer 17

A change in the base sequence of an organism’s DNA

Question 18

What happens if we have a mutation and produce a non- functional enzyme

Answer 18

It won’t work and won’t catalyse the reaction

Question 19

Where do homologous chromosomes come from?

Answer 19

One from Mummy, one from Daddy

Question 20

Where are alleles found?

Answer 20

On the same locus of the chromosome pair