Question 21N.2.SL.TZ0.4
| Date | November 2021 | Marks available | [Maximum mark: 6] | Reference code | 21N.2.SL.TZ0.4 |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain, Outline, State | Question number | 4 | Adapted from | N/A |
This micrograph shows a transverse section of an artery.
[Source: OpenStax College, 2013. Comparison of artery and vein. [image online] Available at:
https://en.wikipedia.org/wiki/File:2102_Comparison_of_Artery_and_Vein.jpg Attribution 3.0 Unported
(CC BY 3.0) https:/creativecommons.org/licenses/by/3.0/deed.en [Accessed 11 March 2020].]
Explain how the specialized structures of arteries help them to achieve their functions.
[3]
a. arteries carry blood at high pressure;
b. rupture of arteries is prevented by thick muscular/elastic walls;
c. narrow lumen to maintain a high blood pressure;
d. elastic tissue allows artery to stretch and recoil (to even out pressures);
e. arteries have muscle layers which contract to increase/control the blood flow;
f. folding in the endothelium allows stretching
OR
smooth endothelium reduces friction;
Most could state that the arteries carry blood at high pressure, but had difficulty getting the other two marks.
State one process that produces ATP.
[1]
(cell) respiration/photosynthesis;
The production of ATP and its use was well known. Although respiration was expected in b(i), photosynthesis was allowed, as ATP is produced in the light-dependent reactions.
Outline the use of ATP.
[1]
source of energy (for use in the cell)
OR
example of use of ATP
OR
when ATP is converted to ADP + Pi (is hydrolyzed) the energy stored in the phosphate bond is released to be used by the cell;
State one function of epinephrine in the human body.
[1]
increases heart rate
OR
prepares the body for action;
In part 4c, many students would have benefitted from the inclusion of (adrenaline) after epinephrine as they seemed to not know of the latter. Epinephrine is the term used in the syllabus (section 6.2), so it was expected that the students were familiar with it.