Unit 01 - the Body and Its Diseases Mark Scheme

Mark Scheme – General Certificate of Education (A-level) Human Biology – Unit 1: The Body and its Diseases – January 2012
3
Question
Marking Guidance
Mark
Comments
1(a)
Phospholipid/lipid/bilayer;
1
1(b)(i)
Protein;
1
1(b)(ii)
2 possible functions;;
e.g. carrier; channel; 2
Allow named examples, e.g. facilitated diffusion, active transport
Accept transport of two substances of ion/molecular size
1(c)
Mitochondrion/mitochondria;
1
Mark Scheme – General Certificate of Education (A-level) Human Biology – Unit 1: The Body and its Diseases – January 2012
4
Question
Marking Guidance
Mark
Comments
2(a)
1. (Blood) vessel/artery/vein used (from other part of body);
2. By-passes blockage in (coronary) artery;
3. Restores blood supply to heart (muscle);
2 max
Accept restores oxygen/glucose to the heart
2(b)
1. Fit into receptors on heart muscle;
2. Block effect of adrenaline/noradrenaline;
3. Prevents rise in heart rate/lowers heart rate;
4. Reduces blood pressure;
5. Reduces likelihood of atheroma/MI/stroke/aneurysm;
2 max
Reject regulates heart rate
Reject artery bursting. Accept thrombus/blood clot
2(c)
1. (Angioplasty) opens blocked (coronary) artery;
2. Increases blood flow to heart muscle / in coronary artery;
3. Increases supply of oxygen / glucose to heart;
2 max
Do not credit incorrect artery
Ignore reduces pressure
Mark Scheme – General Certificate of Education (A-level) Human Biology – Unit 1: The Body and its Diseases – January 2012
5
Question
Marking Guidance
Mark
Comments
3(a)
1. Source of fibre;
2. Slows absorption of sugars/lowers GI/prevents constipation/promotes healthy gut flora/protects against colon cancer/promotes fullness;
3. High in vitamins;
4. High in minerals;
5. Specific effect of vitamin/mineral;
2 max
Reject Vitamin D
3(b)
Any four suitable reasons ;;;;
e.g. No
1. Does not give quantities/portion size;
2. So you don’t know how much energy;
3. Different people/sex/activity level;