2g - Gas Exchange Flashcards
What does the net exchange of gases depend on?
Light Intensity
During the day, do plants make more or less oxygen than they use in respiration?
More
During the day, do plants use up more or less CO2 than they produce?
More
At night do plants take in o2 or release it?
Take it in for respiration
Why is leaves being broad an advantage?
So they have a large surface area for diffusion
Why is leaves being thin an advantage?
So there is short diffusion pathway for the gases
During the day are the stomata open or close?
Open to allow CO2 in for photosynthesis
During the day, do the stomata let water in or out?
Out
At night are the stomata open or closed?
Closed to stop water loss (don’t need to let co2 in)
What happens to guard cells as they open the stomata?
They increase in volume
What happens to guard cells as they close the stomata?
They decrease in volume
What colour is hydrogen carbonate indicator in high co2 levels?
Yellow
What colour is hydrogen carbonate indicator in low co2 levels?
Purple
What colour is hydrogen carbonate indicator in normal CO2 levels?
Red
What’s the function of the ribs?
protects internal organs such as the lungs
What’s the function of the intercostal muscles?
control the movement of ribs - causing inhalation and exhalation
What’s the function of the diaphragm?
Helps change the volume of the thorax
What’s the function of the trachea
Windpipe that connects the mouth and nose to the lung
What’s the function of the alveoli?
Tiny air sacs where gas exchange take place
What’s the function of the pleural membranes ?
Lubricates the lungs to reduce friction
Describing breathing IN:
- intercostal muscles + diaphragm CONTRACT
- rib cage moves UP and OUT
- Thorax INCREASES
- Pressure DECREASES
- Air is drawn IN to lungs
Describe breathing OUT:
- intercostal muscles + diaphragm RELAX
- rib cage moves DOWN and IN
- Thorax DECREASES
- Pressure INCREASES
- Air is drawn OUT of lungs
How are alveoli adapted for gas exchange?
- large surface area
- thin walls
- moist
- good blood supply
- permeable