DNA

Question 1

What does DNA stand for?

Answer 1

DeoxyriboNucleic Acid

Question 2

What is it?

Answer 2

DNA is the chemical that all genetic material in a cell is made up from, it contains codes that are instructions for protein synthesis and bodily functions. It determines your inherited characteristics.

Question 3

Where is it found?

Answer 3

In long structures that usually come in pairs called chromosomes, they are found in the nucleus of cells.

Question 4

What shape and type of molecule is DNA?

Answer 4

A polymer in a double helix shape

Question 5

What are genes?

Answer 5

A gene is a small section of DNA

Question 6

What does MRNA do?

Answer 6

They code for a particular sequence of amino acids which are put together to make a specific protein by telling what order to put the amino acids together

Question 7

How many amino acids are there?

Answer 7

20 but they make up thousands of proteins

Question 8

How does DNA determine cell type?

Answer 8

It determines what proteins the cell produces, such as keratin in hair or nail cells

Question 9

What is the genome?

Answer 9

The genome is the entire set of genetic material in an organism, scientists have worked out the complete genome.

Question 10

Why is it important to understand?

Answer 10

It allows scientists to identify genes in the genome that are linked to diseases, knowing which genes are linked to inherited disease helps us to understand them and develop better treatments for them. Scientists can also look at genomes to trace the migration of certain populations of people worldwide

Question 11

What are nucleotides?

Answer 11

Nucleotides are parts of a DNA strand consisting of a sugar, a phosphate (these two make the backbone) and a base

Question 12

What are the four base letters?

Answer 12

A-T G-C

Question 13

What is this pairing called?

Answer 13

Complimentary base pairing

Question 14

What do the order of bases determine?

Answer 14

The order of amino acids in a protein, coded for in triplets

Question 15

What do parts of DNA do if they don’t code for proteins?

Answer 15

They control whether or not a gene is expressed (used to make a protein).

Question 16

Where are ribosomes located?

Answer 16

In the cytoplasm

Question 17

Why can’t DNA move out of the cell, what is used instead?

Answer 17

DNA is too large to move out of the cell so a molecule called mRNA is used instead. It is made by copying the code from DNA and moving through the cell to the ribosomes in the cytoplasm.

Question 18

What is a carrier molecule?

Answer 18

Molecules that bring the correct amino acid to the ribosome

Question 19

Three examples of different proteins

Answer 19

Enzymes, hormones and structural proteins

Question 20

Enzymes

Answer 20

Act as biological catalysts to speed up chemical reactions in the body

Question 21

Hormones

Answer 21

Used to carry messages around the body, such as insulin which is a hormone in the blood released by the pancreas to regulate blood sugar levels

Question 22

Structural Proteins

Answer 22

Physically strong such as collagen which strengthens connective tissues like ligaments

Question 23

What are mutations?

Answer 23

Mutations are random changes in an organism’s DNA and they can sometimes be inherited.

Question 24

When do they occur?

Answer 24

Mutations occur continuously, they can occur spontaneously such as when a chromosome isn’t replicated properly but the chance of mutation is increased by exposure to specific substances or radiation types

Question 25

What do mutations do?

Answer 25

Mutations change the sequence of DNA bases in a gene which produces a genetic variant, because this sequence codes for amino acids that make up a protein- mutations sometimes change the protein the DNA codes for

Question 26

What effects does a mutation have?

Answer 26

It depends on the type of mutation, some can be harmless and have little to no effect on the protein whereas others can be severe and affect its shape so the protein cannot perform its function

Question 27

What is an example of a protein that cannot function without the correct shape?

Answer 27

Enzymes cannot function without the correct shape as their active sit is changed so a substrate won't bind to it

Question 28

Name the three different mutation types

Answer 28

Insertion, deletion, substitution

Question 29

What are insertions?

Answer 29

Insertions are where a new base is added, they can have a knock on effect in the base code further down the sequence so they can have severe effects

Question 30

What are deletions?

Answer 30

Deletions are where a base is removed from the base code so they can also severely affect the protein produced because they can have a knock on effect

Question 31

What are substitutions?

Answer 31

Substitutions are where a base is swapped to a different base, they do not have a knock on effect so they are often less severe.