Explore how desert organisms conserve water and manage heat, while tropical-rainforest pitcher plants capture insects for mineral nutrients in IB Biology SL B4.1.8.
Convergent evolution increases similarities, despite differences in origins.
Describe adaptations that are typical of plants growing in hot deserts throughout the world.
a. wide-spreading roots
Marking guidance:
allow water collected from large area;
b. water storage tissue/thick leaves/stem survival during (long) droughts/periods without rainfall;
c. deep roots to collect water from greater depths/underground sources;
d. vertical stems to reduce exposure to sun at midday/heating when the sun is overhead/hottest OR pleated stems to allow shrinkage and reswelling/to store water;
e. few stomata transpiration reduced/minimizes;
f. waxy cuticle conserves water;
g. stomata open at night reduces transpiration;
h. no leaves/narrow leaves/leaves as spines/scales decreases surface area/reduces stomata/transpiration/water loss;
i. rolled leaves/hairs around stomata harness humidity/decrease water loss;
j. pitted/sucken stomata reduces transpiration/water loss;
7
max