Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
What needs to be interchanged between organisms and the environment?
|
respiratory gases; nutrients; excretory products; heat
|
|
|
What are the two typed of exchange
|
passive, diffusion and osmosis(no energy required); active, active transport (energy required)
|
|
|
what are the features of a specialised exchange surface
|
large surface area to volume ratio; short diffusion path; partially permeable; air; blood
|
|
|
equation for diffusion
|
|
|
|
how does an insect lower water loss
|
waterproof coverings (cuticle), small SA to V ratio
|
|
|
what is the internal network of tubes in an insect/ single celled organism
|
trachae
|
|
|
what are the trachae divided into?
|
trachaeoles
|
|
|
what are the two ways respiratory gases go in and out of an insects tracheal system
|
along a diffusion gradient, ventilation
|
|
|
how do respiratory gases move in and out of the tracheal system along a diffusion gradient
|
when cells respire, oxygen levels fluctuate so conc towards the end of tracheoles falls creating a diff grad. co2 produced when respiring causing a diff grad in the opp direction.
|
|
|
How do respiratory gases move in and out of the tracheal system through ventilation
|
the movement of the muscles create mass movements in air inside and outside of the trachea. This further speeds up the exchange of respiratory gases.
|
|
|
How do gases enter and leave the trachea
|
spiracles, through evaporation
|
|
|
What happens when the spiracles are closed
|
O2 levels decrease and CO2 levels increase
|
|
|
What are the gills made out of?
|
Gill filaments
|
|
|
What are at a right angle to the gill filaments and what’s their function?
|
Lamellae and to increase SA
|
|
|
What is a counter current flow?
|
Where the flow of blood is in an opposite direction to the flow of water over the gill
|
|
|
How much of the oxygen in the water is diffused into the blood
|
80%
|
|
|
What diffusion does the diffusion gradient favour in the gills
|
the diffusion of oxygen
|
|
|
When photosynthesis is not occurring what happens?
|
Oxygen is being diffused into the leaf as it is constantly in use.
|
|
|
Where does the oxygen and carbon dioxide come from?
|
It comes from the air making diffusion more rapid.
|
|
|
What allows for efficient gas exchange?
|
Being thin and flat for a large SA, stomatas in the lower epidermis, interconnecting air spaces in the mesophyll
|
