Gas exchange

Question 1

What is gaseous exchange

Answer 1

Diffusion of oxygen from the air in the alveoli into the blood and CO2 in the blood to the air in the alveoli

Question 2

How do you find pulmonary ventilation

Answer 2

tidal volume x ventilation rate

Question 3

adaptation of alveoli

Answer 3

Tiny air sacs therefore large SA for gas exchange

Question 4

Adaptation of epithelium cells

Answer 4

Very thin minimises diffusion distance

Question 5

Adaptation of alveolus

Answer 5

Surrounded by a network of capillaries removes exchanged gases therefore maintains concentration gradient

Question 6

Role of external intercostal muscles (inspiration)

Answer 6

Contracts and pulls the ribs up and out

Question 7

Role of external intercostal muscles (Expiration)

Answer 7

Relax

Question 8

Internal intercostal muscles (inspiration)

Answer 8

Relax

Question 9

Role of internal intercostal muscles (Expiration)

Answer 9

Contract and pulls the rib down and in

Question 10

Role of diaphragm (inspiration)

Answer 10

Contracts to move down and flattens

Question 11

Role of diaphragm (expiration)

Answer 11

Relaxed and moves up and down

Question 12

What happens to the air pressure in lungs (inspiration)

Answer 12

Initially drops as air moves in it rises above atmospheric pressure

Question 13

What happens to air pressure in lungs (expiration)

Answer 13

Initially greater than atmospheric pressure, Drops as air moves out

Question 14

Lung volume (inspiration)

Answer 14

Increases

Question 15

Lung volume (expiration)

Answer 15

Decreases

Question 16

Movement of air ( inspiration)

Answer 16

Air moves into lungs as the atmospheric pressure is higher than thorax

Question 17

Movement of air (expiration)

Answer 17

Air moves out the lungs pressure is higher in thorax than atmosphere

Question 18

Features of insects

Answer 18

Exoskeleton made of hard fibrous material for protection
Lipid layer that prevents water loss
They don’t have lungs (Tracheal system trachea, tracheoles and spiracles)

Question 19

What a spiracles role

Answer 19

Round valve like opening along abdomen Co2 and O2 enter and leave via spiracles Trachea attaches to these openings

Question 20

Role of trachea

Answer 20

Internal tube that has rings to strengthen and keep them open

Question 21

Role of tracheoles

Answer 21

Smaller tubes deep in the abdomen which extends to all the tissues and delivers O2 to all respiring cells

Question 22

Name a method of moving gases (1)

Answer 22

Gas exchange diffing cells respire and use up O2 and produces CO2 creating a concentration gradient from tracheoles to air in atmosphere

Question 23

Name a method of moving gases (2)

Answer 23

Mass transport insects contract abdomen muscles to moves gases on mass

Question 24

Name a method of moving gases (3)

Answer 24

Insects in flight muscles cells respire anaerobically and produce lactate the lowers H2O potential of cells therefore H2O moves from tracheoles into cells by osmosis this lowers volume in tracheoles and more air in the atmosphere is drawn in

Question 25

Name a way of limiting water loss (1)

Answer 25

Small SA to volume ratio (where water evaporates from)

Question 26

Name a way of limiting water loss (2)

Answer 26

Waterproof exoskeleton

Question 27

Name a way of limiting water loss (3)

Answer 27

Spiracles ( gas enters H2O evaporates can open/ close - reduces water loss)

Question 28

Features of a fish

Answer 28

Waterproof Have a small SA to volume ratio Obtains O2 from H2O Has a special adaptation to maintain concentration gradient and allows diffusion to occur

Question 29

How do you calculate rate of diffusion

Answer 29

SA x difference in concentration/ length of diffusion path

Question 30

What are the adaptations of a fish

Answer 30

Large SA to volume ratio (Gill filament covered in lamellae Short diffusion distance (Capillaries in lamellae + very thin Maintaining concentration gradient (counter current system)

Question 31

What is the counter current exchange system

Answer 31

H2O flows over the gills in the opposite direction to the flow of blood in capillaries Ensuring a equilibrium cannot be reached So a diffusion gradient is maintained across the entire gill lamellae

Question 32

Features of a plant

Answer 32

O2 diffuses out stomata CO2 diffuses through stomata To reduce water loss stomata closes at night (photosynthesis wont occur)

Question 33

What are Xerophytic plants

Answer 33

Plants adapted to survive in environments limited with water

Question 34

Adaptations of Xerophytic plants

Answer 34

``` Curled leaves Hairs Sunken stomata (traps moisture to increase humidity ) Thicker cuticle (decreases evaporation) Longer root network ( reaches more H2O) ```