Gas Exchange As

Question 1

passage of oxygen being absorbed into lungs

Answer 1

goes into alveoli and dissolves in moist lining of alveolus
diffuses across epithelium
into blood capillary
picked up by red blood cells

Question 2

adaptations of lungs for gas exchange

Answer 2

large SA/volume ratio
short diffusion pathway
partially permeable
concentration gradient maintained with circulation

Question 3

process of muscles in inspiration

Answer 3

external intercostal muscles contract
ribs move up and out volume of thorax increases
diaphragm muscles contract, diaphragm flattens.
pressure decreases
air drawn in
atmospheric pressure higher than pulmonary pressure

Question 4

process of muscles in expiration

Answer 4

internal intercostal muscles contract
ribs move down and in
volume of thorax decreases
diaphragm muscles relax, diaphragm moves up
volume decreases, pressure increases
pulmonary pressure more than the atmosphere so air moves out

Question 5

define pulmonary ventilation

Answer 5

total volume of air moved into the lungs in one minute

Question 6

equation for pulmonary ventilation

Answer 6

pulmonary ventilation=tidal vol X ventilation rate

Question 7

what causes large surface area in lungs

Answer 7

many alveoli

Question 8

what gives a short diffusion pathway in lungs

Answer 8

single layer of epithelial cells and endothelial cells in capillary walls

Question 9

what maintains the concentration gradient in lungs

Answer 9

constant ventilation and circulation

Question 10

adaptations of fish gills for absorption of oxygen

Answer 10

large surface area/volume ratio
short diffusion pathway
high concentration gradient

Question 11

how does a fish gill maintain a high concentration gradient

Answer 11

counter current system maintains high concentration gradient along the whole length of the gill. circulation replaces blood saturated with oxygen

Question 12

how does a fish gill have a high surface area

Answer 12

many lamellae/filaments

Question 13

how does a fish gill keep a short diffusion pathway

Answer 13

thin epithelium

Question 14

adaptations of an insect to absorb oxygen

Answer 14

large SA/volume ratio
prevents water loss
simple diffusion along tracheoles to respiring tissues
maintaining a concentration gradient

Question 15

how does an insect maintain a concentration gradient

Answer 15

oxygen is used in respiration so it diffuses in

Question 16

how do insects keep a large SA/volume ratio

Answer 16

they are small

Question 17

how do insects control water loss

Answer 17

using spiracles

Question 18

do smaller or larger organisms have a higher metabolic rate

Answer 18

larger organisms

Question 19

adaptations of leaves for absorbing CO2

Answer 19

large SA/volume ratio
maintain a concentration gradient of CO2
CO2 are moved by diffusion through stomata controlled by guard cells

Question 20

how do leaves keep a large SA/volume ratio

Answer 20

air spaces between the spongy mesophyll

Question 21

how do leaves maintain a concentration gradient

Answer 21

wind moves around the CO2 near the leaves