Adaptations For Gas Exchange💨 Flashcards
What increases the rate of gas exchange?
- Increasing the surface area
- Reducing the length of the diffusion pathway
- Increasing the steepness of the concentration gradient
What properties do gas exchange surfaces need for efficient gas exchange?
- Permeable to gases
- Moist
- A large surface area
- Thin - short diffusion pathway
- Able to maintain a concentration gradient
Why must gas exchange surfaces be moist?
Because gases must dissolve before they can diffuse across membranes
What is the equation for aerobic respiration?🗣
Oxygen + glucose ->
Carbon dioxide + water
Surface area to volume ratio
The quantity of oxygen required by an organism is proportional to its volume.
The rate of uptake of oxygen from the environment is proportional to its surface area.
What happens to the surface area to volume ratio as an organism increases in size?
It decreases
Adaptations of an amoeba🔍
- Large surface area to volume ratio
- Short diffusion pathways
- Moist
Flatworm adaptations🥓
- Short diffusion pathway
* Large surface area to volume ratio - flat and elongated shape
What is respiration?🗣
A series of oxidation reactions taking place in all living cells.
It results in the release of energy from organic compounds such as glucose.
What is gas exchange?
The diffusion of gases into and out of cells so that respiration can take place
Earthworm adaptations🐛
- Use body surface for gas exchange
- Secrete mucus to maintain moisture
- Elongated shape provides a large surface area to volume ratio
- Closed circulatory system with a well developed capillary network
- Short diffusion pathway
- Haemoglobin in the blood
How do insects reduce water loss?🐞
- Exoskeleton has a waxy cuticle over surface
* Spiracles have valves or hairs
Gas exchange in insects🐞
•They have spiracles which lead to tracheae
•These lead to tracheoles which come into contact with every tissue
The tracheoles have fluid in the ends which dissolve the gases, allowing them to diffuse
Why do tracheae have rings of chitin?🐞
To stop the tubes collapsing and prevent gas exchange of the body
What is the gas exchange surface for insects?🐞
The tracheoles
Advantages of tracheal system🐞
- Every tissue is supplied directly with oxygen
- No circulation or haemoglobin is needed
- Reduced water loss
Ventilation in insects🐞
Contract and relax muscles in thorax and abdomen.
This creates rhythmical movements that ventilate the tracheoles.
How is the tracheal system efficient?🐞
- High surface area - many tracheoles
- Short diffusion pathway - direct
- Moist - fluid in tracheoles
- Permeable - no chitin at ends of tracheoles
- Maintained concentration gradient - ventilation
Gas exchange in amphibians such as a frog🐸
- The larval form uses gills
* The adult uses lungs when active and skin when inactive
How is gas exchange in amphibians efficient?🐸
- Moist skin
- Thin tissues in lungs are thin
- Vascular tissues
Gas exchange in reptiles🐍
•More efficient lungs than amphibians