| Date | November 2015 | Marks available | 1 | Reference code | 15N.3.SL.TZ0.13 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Suggest | Question number | 13 | Adapted from | N/A |
Question
Lizards living in the Kalahari Desert of southern Africa are diurnal (active in daylight). Scientists studied this rhythmical behaviour during different seasons of the year. Observations were made of the number of lizards active each hour and this was recorded as a percentage of the total number of lizards that were active. The graph shows the results for the Southern Spiny Agama (Agama hispida) lizard. Between the hours of 19:00 and 7:00 the lizards were inactive.
State one time in spring when 5 % of the lizards were active.
Winter and summer weather conditions differ in the Kalahari Desert. Compare the results for summer and winter.
The temperatures differ in summer and winter. Suggest one other possible reason why the lizard activity differs in summer and winter.
The body temperature of the lizard is similar to environmental temperature. State the type of receptors that could detect changes in external temperature.
Markscheme
17:00
a. change in behaviour/availability of their prey/food sources;
b. changes in presence of predators;
c. protection from sun (in the middle of the day in summer);
d. amount of daylight hours (is reduced in winter);
Do not accept answers related to temperature eg: cold blooded or poikilothermic.
thermoreceptors/thermo
Examiners report
Most scored 2 marks. A significant number did not compare as required.
Weaker candidates referred to temperature.
