DNA and the Genome

Question 1

What is a gene?

Answer 1

A small section of DNA on a chromosome

Question 2

Describe the structure of DNA

Answer 2

a double helix structure

Question 3

What are the three benefits of studying the human genome?

Answer 3

1. It allows us to search for the genes linked to different types of diseases like cancer
2. It allows us to understand and treat inherited diseases like cystic fibrosis
3. It allows us to trace human migration patterns from the past

Question 4

What is a genome?

Answer 4

The entire genetic material of an organism

Question 5

In order of increasing size, how is the genetic material of eukaryotes organised?

Chromosomes
Nucleus
DNA

Answer 5

DNA → Chromosome → Nucleus

Question 6

DNA is a [blank] of molecules called [blank]

full in the blanks

Answer 6

DNA is a polymer of molecules called nucleotides

Question 7

What are the three molecules which make up the structure of the nucleotide?

draw and label a diagram

Answer 7

Phosphate group (circle)

Sugar molecule (pentagon)

Base (rectangle)

Question 8

How many different types of bases are in DNA?

Answer 8

Four

Question 9

What are the names of the different types of bases?

Answer 9

A, T, C and G

Question 10

Which base is complimentary only to the base of A?

Answer 10

T

Question 11

Which base is complimentary only to the base of T

Answer 11

A

Question 12

Which base is complimentary only to the base of C

Answer 12

G

Question 13

Which base is complimentary only to the base of G

Answer 13

C

Question 14

Describe the process of how proteins are synthesised

Answer 14

In the nucleus →

1) The sequence of bases of the gene is copied into a mRNA molecule
2) The mRNA passes out of the nucleus into the cytoplasm

In the cytoplasm →

1) The mRNA attatches to the ribosome
2) Amino acids are brought to the ribosome by carrier molecules
3) The ribosome then reads the triplets of bases on the mRNA and uses this to join the correct amino acids in the correct order

When the protein chain is completed then the protein folds into its unique shape, this hsape determines its function

Question 15

Give three different types of protein in the body

Answer 15

1) Enzymes
2) Hormones
3) Structural proteins

Question 16

What determines the shape of a protein?

Answer 16

The sequence of bases in the gene for the protein

Question 17

What determines the function of the protein?

Answer 17

The shape of the protein

Question 18

Mutations can code for an altered protein with a different shape.

What will an altered shape mea for an ezyme?

Answer 18

It means that it’s active site will change shape and so the substrate will no longer fit in the binding site

Question 19

Mutations can code for an altered protein with a different shape.

What does this mean for structural proteins like collagen?

Answer 19

The structural protein will lose it strength

Question 20

How many bases are in an amino acid?

Answer 20

Three bases

(triplet bases)

Question 21

Mutations are [blank] and occur [blank] at [blank]

fill in the blank

Answer 21

Mutations are random occur continuously at all times