Outline the various stages of the cell cycle.

Define the term transpiration and explain the factors that can affect transpiration in a typical terrestrial plant.

G₁ the cell grows/duplication of organelles;
S is synthesis stage when DNA is synthesized/replicated;
G₂ the chromosomes begin condensing/preparation for cell division;
G₁ , S and G₂ make up interphase;
during mitosis nuclear division occurs/all four stages listed;
during cytokinesis cytoplasm/cell divides/daughter cells formed;

(transpiration is) loss of water vapour from the leaves/stomata (and stems) of plants;
temperature, humidity, light (intensity) and wind all affect transpiration;
high temperatures increase evaporation rate of water/transpiration; (accept converse)
high humidity lowers the rate of water evaporation/transpiration; (accept converse)
air currents/wind increase water evaporation/transpiration; (accept converse)
high light (intensity)/sunlight (usually) increases photosynthesis/water evaporation through the stomata/transpiration;
stomata open to allow gaseous exchange/entry of CO₂;
abscisic acid stimulates closing of stomata;
guard cells open/close the stomata;
adaptations of (xerophyte) plant structures reduce water loss/transpiration;
one example;
(thicker leaf cuticle / reduced surface area/rolled leaves/spines / sunken/reduced stomata / close stomata in day / low growth form / CAM / C4 physiology)
second example; (of above)
Award [8 max] if definition is missing.

In part (a) many students knew the cell cycle and its parts, but did not fully describe each one. Some students went into very detailed descriptions of the stages of mitosis, only worth one mark, instead of describing the others.

Part (c) was often well answered with candidates write detailed accounts of the effects of the different factors on plant transpiration. However, some described the effects of evaporation of the water in anthropogenic terms of cooling the plant. Also some students wasted valuable time describing the transpiration stream in great detail.