Question 20N.3.HL.TZ0.b
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.3.HL.TZ0.b |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Predict | Question number | b | Adapted from | N/A |
The stomatal density is the number of stomata per area of leaf epidermis. A study was done on the stomatal density of the lower epidermis of leaves from Protium decandrum, a tree found in the Amazon forest.
The image shows the epidermis stripped from the lower surface of a leaf.
[Source: Camargo, M.A.B. and Marenco, R.A., 2011. Density, size and distribution of stomata in 35
rainforest tree species in Central Amazonia. Acta Amazonica, 41(2), pp.205–212. Image courtesy of Miguel from
Camargo & Marenco (2011).]
The mean stomatal density for the lower epidermis of P. decandrum was around 600 per mm2. Predict how the stomatal density for the upper epidermis would compare.
[1]
(upper surface/epidermis usually has) fewer stomata/lower stomatal density/no stomata/OWTTE
Do not accept a numerical value only.
Most predicted that the upper epidermis would have a lower density, although some stated the reverse.
