The Need For Communication Flashcards
Define the term response.
A response is a change in behaviour or physiology as a result of a change in the environment.
Define the term stimulus.
A stimulus is any change in the environment that causes a response.
List the specific set of conditions enzymes require to work efficiently.
- a suitable temperature.
- a suitable pH.
- an aqueous environment that keeps the substrates and products in solution.
- freedom from toxins and excess inhibitors.
What does an external environment of an organism consist of?
The air, water or soil around them.
State what protects many of the cells of multicellular organisms from being exposed to the external environment.
They are protected by epithelial tissues and organs such as skin or bark. In animals the internal cells and tissues are bather in tissue fluid.
State one unwanted/byproduct of a cells metabolism and state what effect it has on the cell.
Carbon dioxide, if this is allowed to build up in the tissue fluid outside the cells it could disrupt the action of enzymes by changing the pH of the environment around the cell.
Define excretion.
The removal of metabolic waste (waste from the reactions inside cells) from the body.
Suggest why a multicellular organism is more efficient than a single-celled organism.
A multicellular organisms cells can be differentiated. Meaning that it’s cells can be specialised to perform particular functions.
State what a good communication system do.
Cover the whole body.
Enable cells to communicate with each other.
Enable specific communication.
Enable rapid communication.
Enable both short-term and long-term responses.
State what is meant by the term cell signalling.
A process in which one cell will release a chemical that is detected by another cell. The second cell will respond to the signal released by the first cell.
List the two major systems of communication that work by cell signalling.
The neuronal system: an interconnected network of neurones that signal to each other across synapse junctions. The neurones can conduct a signal very quickly and enable rapid responses to stimuli that may be changing quickly.
The hormonal system uses the blood to transport it’s signals. Cells in an endocrine organ release the signal (a hormone) directly into the blood. It is carried all over the body but is only recognised by specific target cells. The hormonal system enables longer-term responses to be coordinated.
State three examples of a stimulus and a corresponding response. For each suggest whether it uses the neural system or hormonal system for communication.
Stimulus is feeling the insect bite - response is to move away: nervous coordination.
Stimulus is seeing a large barking dog running towards you - response is to run away: nervous and hormonal coordination.
Stimulus is smelling delicious food - response is to salivate: nervous coordination.
Explain the advantages to the arctic fox of having a thicker, white coat in winter.
The thicker hair traps more air for insulation to prevent heat loss. The white colour gives it camouflage against the snow so it’s prey cannot see it.
State the requirements of a good communication system.
A good communication system must:
- be able to send messages or signals
- be able to receive messages or signals
- distinguish between different messages and signals
- extend over the whole body.
