Communication

Question 1

Why do all cells need to maintain a certain set of conditions inside cells? What are these conditions?

Answer 1

cellular activities rely on enzyme action. Suitable temp, pH, aqueous environment to keep substrates and products in solution, no toxins and excess inhibitors

Question 2

What is a stimulus? What is a response?

Answer 2

any change in environment that causes a response, change in behaviour or physiology as result of environment change

Question 3

What changes in environment will cause gradual response? What is an example of this?

Answer 3

Slowly changing environment: seasons pass, global warming. Artic fox: much thicker white coat in winter, thinner brown coat in summer

Question 4

What does the accumulation of wastes/toxins in the internal environment stimulate?

Answer 4

removal of wastes so cells can survive, may act directly on cells which respond by reducing the activities that produce waste, may not be good for whole organism

Question 5

How is the internal environment of cells maintained?

Answer 5

blood flows throughout body and transports substances to and from cells, any wastes/toxins in tissue fluid enter blood and carried away, accumulation prevented by excretion

Question 6

What will good communication system do?

Answer 6

cover whole body, enable cells to communicate with each other, enable specific and rapid communication, have short and long term responses

Question 7

What are the 2 major systems of communication that work by cell signalling?

Answer 7

neuronal and hormonal

Question 8

What is neuronal system?

Answer 8

interconnected network of neurones that signal to each other across synapse junctions, can conduct signal quickly, rapid response to quickly changing stimuli

Question 9

What is the hormonal system?

Answer 9

uses blood to transport signal, cells in endocrine organs release hormones directly, carried over body but only recognised by target cells, longer term responses