2b.3 - DNA, Meiosis and Mitosis

Question 1

What does DNA contain?

Answer 1

Instructions to put an organism together and make it work

Question 2

Where is DNA found?

Answer 2

In the nucleus of animal and plant cells in long molecules called chromosomes

Question 3

What is a gene?

Answer 3

A section of DNA

Question 4

What do genes contain?

Answer 4

Instructions to make a specific protein

Question 5

How do cells make proteins?

Answer 5

Stringing amino acids together in a particular order

Question 6

How many amino acids are used to make thousands of different proteins?

Answer 6

20

Question 7

How many different proteins can 20 amino acids make?

Answer 7

Thousands

Question 8

What do genes do?

Answer 8

It tells cells in what order to put the amino acids and what proteins the cells produce

Question 9

What are the exceptions to ‘everyone’s DNA is unique’? (2)

Answer 9

• Clones

- Identical twins

Question 10

What is DNA fingerprinting?

Answer 10

It is a way of cutting up a person’s DNA into small sections and then separating them

Question 11

What is DNA fingerprinting used for? (2)

Answer 11

• Forensic science

- Paternity testing

Question 12

What are the advantages to there being a national genetic database?

Answer 12

Easier to solve crimes

Question 13

What are the disadvantages to there being a national genetic database? (3)

Answer 13

• Invasion of privacy
• Sceptical as to what else it could be used for
• False positives or misinterpretations

Question 14

What does mitosis make?

Answer 14

New cells for growth or repair

Question 15

How does mitosis reproduce itself?

Answer 15

By splitting to form two identical offspring

Question 16

Describe the process of mitosis (5)

Answer 16

• Cell gets a signal to divide
• Duplicates itself
• Chromosomes line up along the centre
• Cell fibres pull them apart
• Membranes form and the cytoplasm divides

Question 17

What type of reproduction uses mitosis?

Answer 17

Asexual

Question 18

What are gametes?

Answer 18

Sex cells with half the usual number of chromosomes

Question 19

How many divisions does mitosis involve?

Answer 19

One

Question 20

How many divisions does meiosis involve?

Answer 20

Two

Question 21

Where is the only place meiosis happens?

Answer 21

The reproductive organs

Question 22

What type of cells does meiosis produce?

Answer 22

Cells which have half the normal number of chromosomes

Question 23

Describe the process of meiosis (5)

Answer 23

• DNA duplicates
• Chromosome pair line up along the middle
• Pulled apart by cell fibres
• Chromosomes line up again and pulled again
• Four gametes with a single set of chromosomes