Survival and responseAQA A-Level Biology: Mind map

Exam questions on Survival and response

1. A person touches a hot saucepan handle and snatches her hand away before she feels any pain. The response is a simple reflex that uses a three-neurone pathway.
   Explain why this reflex helps the person to survive.2 marks
2. A pea seedling is laid on its side in complete darkness. After two days the root has curved downwards and the shoot has curved upwards. Measurements show that indoleacetic acid (IAA) has moved to the lower side of both the root and the shoot.
   Explain how the movement of IAA causes the shoot to curve upwards.2 marks
3. A student uses a choice chamber to investigate the response of woodlice to humidity. The chamber has two halves that can be set to different humidities, with a gauze floor above them. She places 20 woodlice in the centre and counts how many are in each half after 10 minutes. She repeats the investigation five times. The numbers of woodlice in the humid half were 15, 16, 13, 17 and 14.
   Describe how the student should set up the choice chamber so that humidity is the only variable that differs between the two halves.3 marks