Diffusion

Question 1

What is diffusion?

Answer 1

The net movement of particles in a solution or a gas from an area of high concentration to a lower concentration

Question 2

What affects rate of diffusion?

Answer 2

Temperature, concentration gradient, surface area to volume ratio

Question 3

Order of lungs (smallest to largest)

Answer 3

Alveoli, bronchioles, bronchi, trachea

Question 4

What do you find in a alveoli?

Answer 4

Tiny blood vessel called capillary, only one rbc can pass at a time

Question 5

What is low and high levels in blood from body before capillary?

Answer 5

Low=oxygen high=CO2

Question 6

What is low and high levels in blood from body after capillary?

Answer 6

High=oxygen low=CO2

Question 7

What happens in alveoli

Answer 7

Oxygen flows to capillary and co2 leaves capillary

Question 8

Human What is the steep concentration gradient?

Answer 8

Ventilation circulation

Question 9

How far is oxygen in alveoli from capillary?

Answer 9

2 cells

Question 10

How do fish breath?

Answer 10

Through gills breathing oxygen dissolved in water

Question 11

What do you find zooming in gills

Answer 11

Filaments, feathery like extensions

Question 12

Fish Steep concentration gradient?

Answer 12

Well ventilated - oxygenated water constantly forced over gills
Rich blood supply to each lamellae of deoxygenated blood that flows in the opposite direction to the water, fully saturating with oxygen before visiting the body cells of the fish

Question 13

What do you find zooming in filaments

Answer 13

Lamellae

Question 14

Fish Short diffusion distance?

Answer 14

Thin membranes between the capillaries and the water (1 cell thick)

Question 15

Fish Large surface area

Answer 15

Having lots of filaments, each studded with several lamellae

Question 16

How does co2 enter leaf

Answer 16

Stomata

Question 17

Where does photosynthesis occur

Answer 17

Palisade cells

Question 18

Where does the co2 go after entering leaf

Answer 18

Moves into and fills the air spaces between the cells in the lower layer of the leaf before diffusing down the concentration gradient toward the palisade cells at the upper side of leaf

Question 19

How does water enter roots

Answer 19

Though root hair cells by osmosis

Question 20

What happens after water enters root

Answer 20

It will keep moving through several other root hair cells until it reaches the xylem vessel

Question 21

What is a xylem vessel

Answer 21

A tube that goes all the way up the stem

Question 22

What happens when water reaches the leaves

Answer 22

Xylem vessels are all bundled together in the veins of the leaf

Question 23

What happens when water reaches the xylem tubes within the leaf vein?

Answer 23

Water diffuses by osmosis out of the xylem tubes through the air spaces in the leaf, and will meet the co2 in the photosynthesising palisade cells in the upper layer of the leaf, closest to sun and when the sun is shining co2 and water will react in the palisade cell to produce the products of photosynthesis

Question 24

Plants Steep concentration gradient

Answer 24

Constant use of water and co2 in the leaf for photosynthesis creates a ‘void ‘ for more carbon dioxide and water to fill

Question 25

Plants short diffusion distance

Answer 25

Leaves are thin and flat (approx. 0.5 mm)

Question 26

Plants Large surface area

Answer 26

Lots of cell membrane in contact with air spaces in the leaf
Large extended cell membrane in the root hair cell’s hair-like extensions
Often many leaves

Question 27

What is the small intestine?

Answer 27

A tube that forms part of your digestive system

Question 28

Where does the food travel?

Answer 28

Through the lumen of the tube in small intestine

Question 29

What happens in the lumen

Answer 29

Food is broken up into smaller pieces so that it can go all the way out from this lumen and into the blood stream

Question 30

What is in the lumen?

Answer 30

Villus=1 villi=many

Question 31

Small intestine large surface area?

Answer 31

Good blood supply

Question 32

Small intestine (villus) short diffusion distance?

Answer 32

1 cell thick

Question 33

Small intestine steep concentration gradient

Answer 33

Continuous blood flow