Questions Corrections 2923

Question 1

Conversion for g to mg

Answer 1

1g = 1000mg

Question 2

Suggest one reason why a report making claims about the side effects of a chemical may be biased

Answer 2

Financial gain

Question 3

Arteries vs veins

Answer 3

Arteries have thicker muscle tissue
Arteries have thicker elastic tissue
Arteries have narrower lumen
Arteries do not contain valves

Question 4

Explain how one treatment for blockage in a coronary artery works

Answer 4

Insert stent
To open coronary artery

Question 5

Explain the effect of a partly blocked coronary artery

Answer 5

Reduced blood flow to the heart so reduced oxygen and glucose to the heart
So less aerobic respiration and more anaerobic respiration so less energy released
So less muscle contraction so less oxygen around the body from the heart
Less CO2 removed from the body resulting in breathlessness and tiredness with a production of lactic acid causing muscle pain

Question 7

How do salmonella bacteria in food cause symptoms of vomiting and diarrhoea

Answer 7

Bacteria release toxins

Question 8

Three asceptic techniques in when culturing microorganisms

Answer 8

Pass inoculating loop through a flame
Sterilise Petri dish
Secure lid of Petri dish with adhesive tape

Question 9

Explain why scientists use 37 Celsius but students use 25 Celsius

Answer 9

37 is body temperature
Bacteria grows best at 37
So 25 reduces the growth of bacteria that are harmful to students

Question 10

Some antibiotics work as they damage the bacteria’s cell wall
Bacteria die because the cells burst explain why

Answer 10

Water enters the bacterial cell
By osmosis
So damaged cell wall cannot withstand pressure of water

Question 11

Explain two effects of anaerobic respiration on the persons body

Answer 11

Muscle fatigue due to build of of lactic acid
Heavy breathing to repay the oxygen debt

Question 12

Explain how taking anabolic steroids could improve an athlete’s performance

Answer 12

Athlete is stronger
(Because of more muscle mass so) more muscle contractions

Question 13

Describe how scientists make monoclonal antibodies using the cell created when a mouse lymphocyte and tumour cell combine

Answer 13

Cell is clones
Many identical cells are produced
All the cells make the same antibody
Antibody is collected and purified

Question 14

A drug stops the synthesis of new DNA bases in the cell suggest how the drug prevents mitosis occurring

Answer 14

(No bases so)DNA replication cannot occur