coordination

Question 1

Why are communication systems needed in animals and plants?

Answer 1

Most animals and plants are multicellular.

Different parts perform different functions.

Activities must be coordinated, so information must be passed around ,done by communication between cells/cell signalling

Animals and plants also need to communicate externally with each other.

Question 2

What is a communication system ?

Answer 2

-Cells communicate

• through chemical signalling/electrical impulses
• enabling communication between

-adjacent and distant cells

Question 3

state features of a good communication system in animals and plants:

Answer 3

Covers the whole body.

Provides specific and rapid communication.

Allows for short term and long term responses.

Cells need to communicate to each other (sometimes multiple cells at once).

Question 4

describe how cells are able to communicate with one another/ describe cell signalling

Answer 4

• one cell release a specific chemical via exocytosis

-that chemical then has an effect only on a target cell

This is because it has the specific receptors which are complimentary to its shape

Question 5

what is a stimulus?

Answer 5

change in the internal/external environment

Question 5

what is a receptor

Answer 5

• they are specialist proteins which detect stimuli-changes in the surroundings

and pass information to effectors so they can produce a response to the stimulus

Question 5

Why do living things need to maintain a certain set of conditions in their cells?

Answer 5

Because of the need for a relatively constant internal environment.- maintained via the process of of homeostasis

Cellular activities rely on enzymes,

• and enzymes require a specific set of conditions to function

such as suitable temperature and pH

, an aqueous environment to keep substrates and products in solution

, and an environment free from toxins and inhibitors.

Question 5

what is the definition for homeostasis

Answer 5

-Homeostasis is the maintenance of a constant internal environment

-by coordinating the function of the organs

-for example many organs work together to maintain a constant blood glucose concentration

-despite external changes.

E.g blood salt concentration, body pH, body temperature, CO_2 concentration , blood pH, blood glucose concentration, blood pressure.

Question 5

what is an effector?

Answer 5

it can be a muscle or gland which produces a response to a stimulus according to the information received by the nervous system

Question 5

what is a communication pathway?

Answer 5

A link between a receptor and effector which may be neuronal or hormonal.

Question 5

state external changes organisms must respond to

Answer 5

-external temperature
-humidity
-light intensity
-new/sudden sound

Question 5

what are the two communication systems we have ?

Answer 5

-nervous system

-hormonal system

Question 5

state examples of internal changes organisms must respond to

Answer 5

-blood glucose concentration
-water potential
-ph of cells
-internal temperature

Question 6

what communication systems do animals and plants use to respond to changes in the environment

Answer 6

animals use both the neural system ,through electrical impulses and the hormonal system though hormones

-animals use the hormonal system only, have many hormonal communication systems which must be coordinated to produce the required response

Question 7

what is coordination

Answer 7

-the working together of various organs/cells in the body of an organism

-to produce a response to a stimulus

Question 7

what is water potential

Answer 7

its the pressure exerted by water molecules on membranes

Question 8

why is coordination necessary?

Answer 8

-organisms need to respond to internal/external changes

-Different organs work together to ensure homeostasis ,for example by cell signalling

-animals respond to environment changes through the nervous and hormonal system ,whereas plants respond to environmental changes only though the hormonal system

As well as that cells rely on other cell for substances like glucose and oxygen

They also rely to other cells for the removal of waste

Question 9

what does cell signalling allow cells to :

Answer 9

• cell can transfer signals locally

-cells can also transfer signals across long distances

Question 10

do plants have a nervous system and how do they respond to environment changes

Answer 10

-plants dont have a nervous system

-they respond to changes via hormonal communication systems using plant hormones

Question 11

state all the difference in the type of messengers used by the nervous and hormonal system

Answer 11

-the hormonal system uses hormones ,whereas the nervous system uses electrical impulses

Question 12

differences in transmission in the two communication systems

Answer 12

-hormonal systems is by the blood ,whereas in the nervous system is by neurones

Question 13

difference in the speed of transmission of the two communication systems

Answer 13

-for hormonal system is relatively slow, whereas for nervous system is relatively fast

Question 14

difference in the speed of response of the two communication systems

Answer 14

-slower in hormonal system and rapid in the nervous system

Question 15

difference in the duration of response of the two communication systems

Answer 15

• response is longer lasting in the hormonal system and short lived in the nervous system

Question 16

difference in the duration of effects of the two communication systems

Answer 16

-effect is permanent and irreversible for the hormonal system and reversible for the nervous system