Gas exchange

Question 1

what are some examples of passive transport

Answer 1

osmosis, diffusion, facilitated diffusion

Question 2

what are some examples of active transport

Answer 2

active transport and co-transport because thye both require ATP to move against the conc grad

Question 3

why do small organisms not have gas exchange systems

Answer 3

because their surface area to volume ratios are large enough to facilitate the diffusiin of substances without needing a transporter intermediary

Question 4

how are exchange surfaces adapted to the function - generally

Answer 4

thin membranes - shorter diffusion pathway allows for rapid diffusion

large surface area to vol ratio

some may be selectivrly permeable

Question 5

what is ficks law?

Answer 5

diffusion is proportional = surface area x difference in conc /length of diffusion pathway

Question 6

what are the component of an insects gas exchange system

Answer 6

trachea
tracheoles
respiring tissue
spiracles

Question 7

what is the trachea in the insects made of

Answer 7

supported by strengthened rings to prevent collapse

Question 8

what do the tracheoles do

Answer 8

they extend therough the body of the insect - this way o2 is brought directly to the respiring tissue

Question 9

what is the function of the spiracle s

Answer 9

open and close to prevent the loss of water like the stomata

Question 10

what is the structure of the gills
just tell me little words facts

Answer 10

gill filaments
lamellea

Question 11

what are the gill filaments

Answer 11

stacks of gills stacked up high

Question 12

where is the gill lamelea located

Answer 12

at a right angle to the gill filaments

Question 13

what does the gill lamellae do

Answer 13

increase SA of the gills.

Question 14

what is the counter current flow system

Answer 14

where the flow of water and blood will flow in the opposite direction to one another over the lamellae

Question 15

what does the gill lamellae look like

Answer 15

like little stacks on top of the filament to increase the surface area of the gill and so mmore o2 can get to fish

Question 16

what are the organelles in a plant

Answer 16

stomata
- palisade mesophyll
upper epidermis
chloroplasts
vacuole
air space
guard cell
waxy cuticle
lower epidermis

Question 17

what is the function of the stomata

Answer 17

to open and close to allow gaseous exchange. to guard cells control this via keeping them open if they are flaccid - not a lot of water or closed by being turgid

Question 18

what is a xerophyte

Answer 18

plants specially adapted for warm, dry or windy environments where water loss is a problem -water lossss

Question 19

what are some adaptations to xerophytes

Answer 19

stomata in sunken pits that trap moist air therefore reducing conc grad of water between air and the leaf. this reduces the amount of water diffsuing out the leaf and evaporating away
- a layer of hairs on the epidermis to trap air around the stomata

• curled leaves with the stomata inside protecting them from wind

-a reduced number of stomata
- waxy, waterproof cuticles on leaves and stems to reduce evaporation

Question 20

where is the main gas exchange surface on the plant

Answer 20

surface of the palisade mesophyll cells - good because big SA

Question 21

how do insects limit water loss

Answer 21

spiracles
small surface area to vol ratio
waterproof coverings

Question 22

define transpiration

Answer 22

water loss

Question 23

describe the lungs

Answer 23

a pair of lobed structure that are made up of highly branched tubules called bronchioles which end in tiny air sacs

Question 24

describe the human trachea

Answer 24

supported by rings of cartilage that prevents collapse with the fall in air pressure when breathing in

Question 25

what are the tracheal walls lined with

Answer 25

ciliated epithileum cells - wafting
goblet cells - to produce mucus

preventing infection

Question 26

what are alveoli

Answer 26

tiny air sacs at the end of the bronchioles that are laced in a network of capillaries. between the alveoli there are elastic fibres that allow them to stretch as they fill with air and spring back when exhaling

Question 27

describe the mechanism of inspiration

Answer 27

the ribcage moves up and out to increase the volume of the thoracic cavity. external intercostal muscles contract and diaphragm muscle contract whilst the internal intercostal muscles relax. due to the greater volume in the thoracic cavity the pressure decreases to lower than atmospheric and therefore air will be forced in via a pressure gradient

Question 28

describe the mechanism of expiration

Answer 28

the ribcage moves down and in to increase pressure. the external intercostal muscles and diaphragm muscle relax and the internal intercostal muscles contract. the pulmonary pressure is now higher than atmospheric due to the decreased volume. air is forced out along the pressure gradient

Question 29

why are rbcs slowed as they pass through the pulmonary capillary

Answer 29

because they are so large in compariosn to teh capillary so only one can fit in a cross section

Question 30

what are four things that allow diffusion of gases between the alveoli and the rbc to be rapid

Answer 30

-red blood cells are slowed as they pass through the pulmonary capillaries which allows more time for diffusion
- the walls of both the alveoli and capillary are very thin so the diffusion pathway is very thin
- alveoli and capillaries have a very large total syrface area
- blood flow through the capillaries maintains a concentration grad

Question 31

when does a correlation occur

Answer 31

when a change in one of two variables is reflected by a change in the other variable

Question 32

what is emphysema

Answer 32

a break down in elastin in the alveolar tissue which inhibits the stretch and recoil function in inspiration and expiration.
- alveoli can fuse together but this means that there is large air sacs with a smaller surface area to volume ration which therefore decreases the rate of diffusion

Question 33

what is chronic bronchitis

Answer 33

symptoms must persist for more than three months
- more mucus is produced as cilia are destroyed.
- tar in cigarettes which destroy the cilia and causes mucus glands to enlarge as less is able to move up the trachea
- scar tissue will form via fibrosis. the scar tissue replaces the epithelium lining and will therefore narrow the trachea
- bacteria will gather in the mucus will can lead to infection or in severe cases pneumonia

Question 34

describe fibrosis

Answer 34

involves scarring of the lung tissue ( epithelium lining is replaced and therefore elasticity is reduced).
- FEV1 and FVC will reduce -> less o2
- also leads to thicker walls which increases the diffusion pathway distance and therefore slows diffusion

Question 35

what is asthma

Answer 35

there is an obstruction in the airways. there is inflammation and bronchoconstricion ( constriction of bronchioles).
this is all caused by an allergic reaction.
broncocontriction disrupts normal breathing rates and leads to a reduction in normal ventilation. lower FEV1 and could be in a deprivation of O2

Question 36

define FVC

Answer 36

forced vital capacity - the maximum amount of air possible to expel after a deep breath in

Question 37

define FEV1

Answer 37

the maximum volume of air that can breathed out in 1 second