last minute

Question 1

What happens to the cell cycle as someone gets older?

Answer 1

Gets shorter, slows down after puberty

Question 2

What are the uses of Mitosis?

Answer 2

GROWTH
REPLACE DEAD CELLS
REPAIR TISSUE

Question 3

What cells are replaced as someone gets older?

Answer 3

• blood cells
• hair cells
• skin cells
• lining of small intestine cells

Question 4

Why is it hard to clone animals?

Answer 4

Specialisation is permanent

Question 5

What is therapeutic cloning?

Answer 5

Taking a stem cell from an adult
to produce a cloned early embryo of themselves

-adv= no risk of rejection

Question 6

Chemical defenses in plants

Answer 6

• antibacterial chemicals
• poisons

Question 7

Physical defenses in plants

Answer 7

• thorns
• waxy cuticles
• hairy stems

Question 8

Mechanical

Answer 8

• ## droops or curls when touched

Question 9

Uses of monoclonal antibodies

Answer 9

1. direct use is to send a signal triggering immune system to recognise, attack and destroy cancer cells
2. using monoclonal antibodies to carry toxic drugs or radioactive substances (radioactive therapy) or chemicals to stop it growing and attack cancer cells directly

Adv - doesn’t affect healhy cells
Disadv - expensive to develop

Question 10

Affect of smoking?

Answer 10

1. nicotine –> addictive substance but relatively harmfull –> produces a sensation of calm, well-being and being able to cope
2. CO –> poisonous gas - in pregnant women this leads to premature births, low birthweight babies and stillbirths
3. cilia in trachea and bronchi become anaesthetised by some chemicals in cig smoke –> can’t expel mucus –> more chesty coughs in an attempt to get mucus up and out
4. tar accumulates in lungs
5. can lead to COPD - chronic obstructive pulmonary disease

Nicotine increases heart rate and other chemicals damage lining of arteries
Cigarette smoking makes CHD more likely and increases risk of clot formations
chemicals increases blood pressure