Exchange Surface and fish and insect

Question 1

What two factors affect the rate of exchange?

Answer 1

size and metabolism

Question 2

What do humans exchange?

How can these be exchanged?

Answer 2

Respiratory gases (o2 and co2)
Nutrients (vitamins, mineral amino acid and glucose)
Excretory Products (urea and co2)
Heat

Actively or passively

Question 3

How have large organism evolved?

Answer 3

Flattened shape and specialised exchange surface

Question 4

What make gas exchange efficient?

Answer 4

large surface area to volume ratio

low metabolism

Question 5

State Fix’s law

Answer 5

diffusion ∝ SA X concentration/ length of dif. pathway

Question 6

State the features of a specialised exchange surface and how that helps

Answer 6

Large SA: Vol ( increases the rate of exchange)
thin ( short diffusion pathway)
 selectively permeable (only select material can cross the medium)
a transport system to ensure the movement of internal medium

Question 7

How are single-celled organisms adapted for exchange?

Answer 7

they are small so have a large SA: Vol,
only cell surface membrane to diffuse through hence a short diffusion pathway.
reference to diffusion and material exchange
they rely on diffusion so limits the size they can go

Question 8

Name the parts of an Insects exchange system

Answer 8

Spiracle
trachea
tracheoles
fluid-filled end

Question 9

Name the four ways respiratory gases move in and out of the tracheal system

Answer 9

Along a diffusion gradient
Mass Transport
End of tracheoles filled with H20
Spiracles

Question 10

Describe the mass transport process in insects

Answer 10

contraction of muscles squeeze trachea

Question 11

Describe the how the end of the tracheoles fill with water and how that benefit exchange in insects

Answer 11

Exercise, muscle produce lactate which lowers water potential of the cell
so H2O moves into cells from tracheoles, less H2O in tracheoles more air quicker tan liquid phase.

Question 12

Describe how concentration gradient are used in insect exchange

Answer 12

Respiration uses up O2 so concentration at end of tracheole falls creating diffusion gradient from atmosphere to trachea to tracheoles
CO2 produced created con. gradient in opposite dir.

Question 13

Describe how the spiracles work in insects

Answer 13

when gases enter and leave the spiracles ( valve) open and close.

when open h2o can be lost

Question 14

Describe the o2 levels in water

Where is it higher?

Answer 14

Water is not rich in O2
Higher at the surface as plants use o2 and o2 dissolves int the water
warm water has less o2 than cool

Question 15

Name the parts of a fish exchange system

Answer 15

gill cover
gill opening
FOUR gill arches
gill filaments ( with lamellae)

Question 16

How is a fish adapted for gas exchange?

Answer 16

Gill filaments/lamellae
increase area for diffusion
counter-current system
thin epithelium 
circulation replaces blood
ventilation replaces o2

Question 17

How does water enter and leave a fishes body?

Answer 17

water is taken in through the mouth and forced over the gills and out through an opening on each side of the body

Question 18

What is counter-current flow?

Answer 18

blood and water flow in opposite dir.
maintains a difference in O2 con.
a high diffusion gradient across all of lamella
ensures o2 con. is always higher in water so oxygen diffuses from the water