Edexcel IGCSE Biology 2.90 Simple Reflex Arc Questions
Trace a hot stimulus from skin receptor through sensory, relay and motor neurones to an effector; synapses and muscle response add time.
- Syllabus
- First assessment 2019
- Course
- Biology 4BI1
Exam points
- Trace a withdrawal reflex from a skin receptor through sensory, relay and motor neurones to an effector.
- Identify receptors, neurone types, relay cell bodies and effectors in a labelled reflex-arc diagram.
- Define a reflex response as automatic or involuntary.
- Explain how a rapid withdrawal reflex limits damage by moving a finger away from a hot object.
- Explain why measured response time exceeds impulse travel time because impulses must cross synapses and the receptor or muscle takes time to respond.
Edexcel IGCSE Biology 2.90 Simple Reflex Arc Questions question 1
[Maximum number: 4]
Reflexes are responses that protect the body and involve the central nervous system (CNS).
If an animal steps on a sharp object, a reflex arc occurs so that it picks up its foot to prevent further damage.
Describe how named neurones bring about a withdrawal reflex to protect the animal from damage.
A description that makes reference to four of the following points:
- receptor receives / senses / detects (object) / eq
- impulse
- (impulse moves along) sensory neurone to CNS / spinal cord / relay neurone
- (chemical diffusion of) neurotransmitters across synapse
- motor neurone to effector / muscle
- (muscle) contracts
signal /
message
All question bank results loaded