Controlling Change

A Year 11 module from the Salters Key Stage Four double award science course. This module introduces ideas about how living organisms control their internal environment and respond to changes in their external environment. Students are reminded that few living things can survive for long without water. A text exercise is used to review students’ knowledge of the movement of water through plants. On the basis of this, they select from a circus of activities to fill gaps in their knowledge.

Students test their speed of reaction to sight, sound and touch stimuli. A text activity shows the component parts of the central nervous system and the reflex arc. The operation of the nervous system is compared to mechanical and electronic systems. The importance of feedback is considered.

The endocrine system is compared with the nervous system. Students compile information about some important glands, the hormones which they secrete and the functions of those hormones. The importance of feedback control in the endocrine system is also reviewed. Some effects of hormones on plant growth are studied and commercial applications of plant hormones are introduced.

Section 1: Steady as you go
Temperature control is studied as an introduction to how organisms control their internal environment. Methods of temperature control in animals are studied and students consider the structure and functions of skin.

Section 2: Water and plant life
Students study the movement of water across membranes by osmosis. A text exercise is used to review students’ knowledge of the movement of water through plants. On the basis of this, they select from a circus of activities to fill gaps in their knowledge.

Section 3: How fast do your nerves react?
The five senses are considered. Students test their speed of reaction to sight, sound and touch stimuli. A text activity shows the component parts of the central nervous system and how the reflex arc provides fast initial response to danger. The operation of the nervous system is compared to mechanical and electronic systems. The importance of feedback in maintaining stable conditions is considered.
From yr 11 pack: p106 components of the CNS

Section 4: Chemical messengers
The endocrine system is compared with the nervous system. Through a series of text activities, students compile information about some important glands, the hormones which they secrete and the functions of those hormones. The importance of feedback control in the endocrine system is also reviewed. Some effects of hormones on plant growth are studied and possible explanations of phototropism are considered. Commercial applications of plant hormones are introduced.

From yr 11 pack page 111 comparing nervous and endocrine systems