3.3.2 Gas Exchange Flashcards
Why aren’t insects bigger?
More cell more demand of oxygen
Tracheal system could not meet respiratory demand
Especially there’s low oxygen concentration in the air
Mass of exoskeleton increase , decrease the speed of movement
How do you reduce water loss of an insect?
Lipid layer
Hard exoskeleton, polysaccharide chitin
Spiracle close
Small surface area to volume ratio
Hair and waxy cuticle around the body
Describe and explain the tracheal system of insect
tracheae held by rings of chitin
Prevent collapsing, keep them open
Tracheoles is extant throughout all the insects body tissue (thin and permeable)
Carrying oxygen directly to respiring cells and removing carbon dioxide
Short diffusion pathway from tracheoles to body cell only with 1 layer of cell
Spiracle equipped it with valves , atrium, and dust filter to trap humid air
Fluid filled end of tracheoles
What is the movement of gas cause by?
Concentration and diffusion gradient
Contraction of muscles around the tracheal system (rhythmic, abdominal movement)
End of tracheoles are filled with water
Adaptation to gas exchange of insect
Large surface area allowed, a large number of fine tracheoles
Three ways of gas exchange
Diffusion
Mass transport
Contract and relax abdominal muscle which squeeze the air sac to move the air from sacs to tracheoles and use the air when spiracle is closed
Change volume of thorax / Abdomen pressure change in tracheae to push the air in and out
Anaerobic respiration
Produce lactate
decrease water potential of the cell
Allow water to move from tracheoles to the cell by osmosis
Decrease the volume in tracheae, decrease the pressure
So the air is drawn in
The end of trachea this connects directly with the inside tomato tissue and filled with water when flying water is absorbed into the master tissue removal of water from the tracheoles increase the rate of diffusion of oxygen between the tracheoles and muscle tissue. Suggest one reason why.
Guess Move and feels faster in air than water
Increase volume of water
Leaf structure, description
Waxy cuticle: prevent water loss
Upper and lower epidermis : allow light to penetrate so photosynthesis happen in the chloroplast
Palisade mesophyll : a vertical, compact, maximise chloroplasts exposed to light
Spongy mesophyll: with air, space, increase surface area exposed to the air, faster diffusion
Stomata : open in a day allowed water to get in and become turgid, dehydrated loose, water flaccid closed
Guard cell : expand/ strink , open and close the stomata
How old is guard cell Open the stomata?
When I get enough water, it doesn’t matter to lose some when open it
Inner wall can’t expand as much
adaptation of leaf structure
Thin and flat, large surface area to volume ratio
Stomata on the lower surface , reduce evaporation rate as it is shady, and damp
No cell far from the source of air because there is interconnecting air space, so the diffusion distance are short
Adaptation of Xerophytes
Thick waxy cuticle : prevent water loss, waterproof, impermeable
Needle leaves : decrease surface area to volume ratio
Spikes : defends from insect , drinking the water, decrease surface area to volume ratio
Stomata sunken in the folded area : shady prevent sunlight and wind, so to reduce concentration gradient, and conserve, water, high humidity, saturatedlayer of still there inside
Hair and curled leaves : trap moisture, increase local humidity, maintain shallow concentration gradient
Longer route network : to reach water underneath
Some herbicides cause the stomata of plans to close. Such as how do use herbicide might lead to the death of the plant.
When there’s herbicide the stomata close, there is the need to get exchange happen, and some interexchange of O2 and CO2 for photosynthesis. Near the process can continue indefinitely by relying exclusively on gas produced by the other. Some gas must be obtained from the environment. no supply both photosynthesis and respiration will ultimately stopped and the plants will die
Why does bird need more gas than jellyfish?
More energetic
Maintain body temperature
Nutrients for maintain metabolic rate
Why fish can’t leave water?
Gills, will clumps together, due to water, cohesion and adhesion, reduced surface area for gas exchange
A lot of nutrients in water
One-way respiration, water is denser
Two types of flow in the fish
Counter current flow
Parallel flow
Describe and explain counter current flow
Water and blood flow in opposite direction
Blood is always meeting water with a higher oxygen concentration
Concentration gradient is maintained across the whole length of gills lamellae
Diffusion of oxygen into the blood can occur across the whole length of gills
This ensure maximum possible gas exchange
Describe and explain, parallel proof
Water and blood flow in the same direction
Equilibrium is reached halfway across the gills
No gas diffusion across the whole length
Two. Type of fish
Cartilaginous fish
Bony fish