Coordination and response: Practice Questions

Which structure in the human body acts as an effector in a reflex arc?

Which table row correctly contrasts the characteristics of the human nervous system and endocrine system?

When a plant shoot is exposed to unidirectional light from one side, how does auxin behave to produce positive phototropism?

Which hormone is produced by the testes in human males?

During thermoregulation in a cold environment, how do human skin arterioles and shunt vessels respond to minimise heat loss?

State the site of the human eye where the optic nerve leaves the retina and no photoreceptor cells are present.

A potted plant placed horizontally in complete darkness develops a root that curves downwards and a shoot that curves upwards.
(a) State the name of this growth response to gravity.
(b) Name the chemical substance that coordinates this response.
(c) State the term used to describe the shoot growing upwards away from the gravitational pull.

Explain how the eye accommodates to focus on an object located close to the face.
In your answer, describe the actions of the ciliary muscles, suspensory ligaments, and the resulting change in the lens shape and light refraction.

Both the nervous system and the endocrine system are involved in communication within the human body.
(a) State the form of transmission used by:
(i) the nervous system.
(ii) the endocrine system.
(b) State two differences in the nature of the responses between the nervous system and the endocrine system, with respect to speed and duration of action.

The human eye detects light using specialised photoreceptor cells located in the retina.
(a) Identify the two types of photoreceptor cells present in the human retina.
(b) State two functional differences between these two types of photoreceptor cells.
(c) Name the specific area of the retina that contains the highest concentration of cone cells and gives the sharpest image.