Question 23M.2.SL.TZ1.d
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.2.SL.TZ1.d |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Suggest | Question number | d | Adapted from | N/A |
The spider Dolomedes plantarius usually has white bands down the left and right sides of its body, but some individuals lack these bands. The photograph shows the banded form of D. plantarius with a ball of spiderlings.
[Source: photo: Vėlavičienė, N., 2004. [Dolomedes.] [image online] Available at: https://commons.wikimedia.org/wiki/
File:Dolomedes_fimbriatus.jpg. [Accessed 14 March 2022]. Licensed under the Creative Commons Attribution-Share
Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en).]
Crosses were performed to investigate the inheritance of this trait, by allowing specific males and females to mate. Numbers of banded and unbanded spiderlings that hatched out from all the eggs laid by the female were recorded. Results are shown in the table.
[Source: table: Baillie, A.L., Baillie, S.R. and Smith, H., 2019. The heritability of lateral banding in Dolomedes plantarius. Arachnology, [e-journal] 18(3), pp. 237–244. https://doi.org/10.13156/arac.2019.18.3.237.]
The proportion of banded and unbanded individuals in a population of D. plantarius can change. Suggest how such a change could occur.
[1]
- natural selection could favour one type over the other;
- greater survival of one type
OR
one type better camouflaged than the other type; - one type more attractive during courtship/mate selection;
Do not accept a list. Natural selection or sexual selections alone are not adequate.
