Biology- Exchange

HideShow resource information
When organisms exhange substances with the outside environment, what must the materials being transferred always cross?
Cell plasma membranes.
1 of 37
What is the environment outside of a cell called in a mulicellular organism?
Tissue fluid.
2 of 37
What maintains the diffusion gradient with regard to transporting material to and from the cell- surface membrane?
A mass transport system.
3 of 37
What characteristics of an organism determine the amount of each material that is exchanged?
The size and metabolic rate of the organsim.
4 of 37
State examples of materials that need to be interchanged between the organism and the environment.
Respiratory gases such as oxygen and carbon dioxide, nutrients such as glucose, fatty acids, amino acids, vitamins, minerals, and excretory products such as urea and carbon dioxide.
5 of 37
Apart from heat, what two ways can materials be exchanged?
Passively by diffusion and osmosis, actively by active transport.
6 of 37
What does passively mean?
No metabolic energy is required.
7 of 37
What does actively mean with regard to metabolic energy?
Metabolic energy is required.
8 of 37
What part of an organism does exchange take place on?
The surface.
9 of 37
As organisms become bigger, what increases at a faser rate?
Volume increases at a faster rate than their surface area.
10 of 37
How may an organsim be adpated to exchange of materials?
A flattened shape so that no cell is ever far from the surface, e.g. in a flatworm or leaf, or a specialised exchange surface with large areas to increase the surface area to volume ratio e.g. in the lungs of mammals or gills in fish.
11 of 37
State the formula for calculating the surface area of a sphere.
4 pie r squared
12 of 37
State the formula for calculating the volume of a sphere.
4 divided by 3 pie r quebed
13 of 37
What are the main features of a specialised exchange surface?
A large surface area relative to the volume ratio of the organism, very thin exchange surfaces so that the diffusion distance is short and therefore materials can cross the exchange surface rapidly, the membrane is selectively permeale.
14 of 37
Why are specialised exchange surfaces often located inside an organism?
Because they can be easily damaged.
15 of 37
What is the relationship between surface area and volume ratio in a single celled organism?
They have a large surface area to volume ratio.
16 of 37
How does oxygen enter single celled organisms?
Diffusion.
17 of 37
What is the name given to the network of tubes involved in the gas exchange in insects?
Tracheae.
18 of 37
How are the tracheae supported to prevent them from collapsing?
Strengthened rings.
19 of 37
What do tracheae divide into?
Smaller dead end tubes called tracheoles.
20 of 37
Where do tracheoles extend throughout?
Throughout all the body tissues of the insect.
21 of 37
What is there a short diffuesion pathway between in insects?
Between a tracheole and any body cell.
22 of 37
How is a diffusion gradient created in tracheoles of insects?
When cells are respiring, oxygen is used up, so the concentration of oxygen towards the end of the tracheoles falls.
23 of 37
What is produced by cells during respiration?
Carbon Dioxide.
24 of 37
If cells produce carbon dioxide during respiration, what is created to remove it, with regard to the concentration of oxygen?
A diffusion gradient is created in the oposite direction.
25 of 37
What causes the mass movement of air in and out of tracheae?
The contraction of muscles can squeeze the trachea.
26 of 37
What are the ends of tracheoles filled with.
Water.
27 of 37
What do muscle cells carry out during periods of major activity?
Anerobic respiration.
28 of 37
What does anerobic respiration produce?
Lactate.
29 of 37
What does Lactate lower in cells?
Water Potential.
30 of 37
What must lactate be if it lowers the water potential in plants?
Soluble.
31 of 37
What does water moving into cells do to the water in the tracheoles? What does this do with regard to air?
The water in the end of the tracheoles decreases, drawing further air into cells.
32 of 37
What are the tiny pores called on the surface of insects which enable them to breathe?
Spiracles.
33 of 37
How are spiracles opened and closed?
By valves.
34 of 37
When the spiracles are open, what can leave the insect, and by what process?
Water, by evaopartion.
35 of 37
Why does the gas exchange system of insects limit th size they can be?
Because diffusion requires a short pathway to take place.
36 of 37
State the gas exchange surface found in fish.
The gills. z\
37 of 37

Other cards in this set

Card 2

Front

What is the environment outside of a cell called in a mulicellular organism?

Back

Tissue fluid.

Card 3

Front

What maintains the diffusion gradient with regard to transporting material to and from the cell- surface membrane?

Back

Preview of the front of card 3

Card 4

Front

What characteristics of an organism determine the amount of each material that is exchanged?

Back

Preview of the front of card 4

Card 5

Front

State examples of materials that need to be interchanged between the organism and the environment.

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Human, animal and plant physiology resources »