Question 23M.2.SL.TZ2.4
| Date | May 2023 | Marks available | [Maximum mark: 5] | Reference code | 23M.2.SL.TZ2.4 |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Explain, Outline, State | Question number | 4 | Adapted from | N/A |
The Chinese pangolin (Manis pentadactyla) is a critically endangered species that has declined in numbers by 80 % since 2000. It inhabits both forest and grassland, where it uses long, powerful claws to open ant and termite nests and ingests the insects using a long, sticky tongue.
[Source: By U.S. Fish and Wildlife Service Headquarters - Manis pentadactyla, CC BY 2.0,
https://commons.wikimedia.org/w/index.php?curid=56589200.
Photo credit to Ms. Sarita Jnawali of NTNC – Central Zoo The United States is
cosponsoring four separate proposals to increase CITES protections for pangolins
from Appendix II to Appendix I, U.S. Fish and Wildlife Service Headquarters -
Manis pentadactyla. CC BY 2.0. File:Manis pentadactyla (29054818144).jpg.
Created: 14 September 2016.]
State with a reason whether pangolins are autotrophic or heterotrophic.
[1]
heterotrophic because it feeds on/eats food/other organisms /eats ants/termites/ doesn’t photosynthesise/does not produce its own food;
Do not accept “it is not autotrophic” as it is part of the stem question.
Many did not give a suitable reason why pangolins are heterotrophs.
Explain what information is needed to find the trophic level of pangolins.
[2]
- what (prey) it eats/feeds on/ stomach content;
- the trophic level of what (prey) it eats/feeds on/the trophic level of ants/termites;
- trophic level is the position an organism occupies in the food chain/web;
Do not award points for indicating that predator information is needed.
(ii) was quite well attempted, with reference to the prey of the Pangolin and what the prey eats. The predators of the pangolin are immaterial as this does not inform about its trophic level.
Outline evidence for evolution from the limbs of mammals such as pangolins.
[2]
- pentadactyl;
- homologous with limbs of other vertebrates;
- due to common ancestry;
- adaptation;
The answers to (b) were probably centre dependent as many could describe the pentadactyl limb, homologous structures and a common ancestor, whilst others struggled.