6.2: Gas exchange in single-celled organisms and insects Flashcards
Every cell of an insect is only what, so the diffusion pathway is always short?
Every cell of an insect is only a very short distance from of the:
1. Tracheae
Or,
2. Tracheoles
,so the diffusion pathway is always short
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, what have insects evolved?
For gas exchange, insects have evolved an internal network of tubes called tracheae
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
What are the tracheae supported by?
The tracheae are supported by strengthened rings
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
The tracheae are supported by strengthened rings to do what?
The tracheae are supported by strengthened rings to prevent them from collapsing
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
The tracheae are supported by strengthened rings to prevent them from collapsing.
What do the tracheae divide into?
The tracheae divide into smaller, branched tubes called tracheoles
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
The tracheae are supported by strengthened rings to prevent them from collapsing.
The tracheae divide into smaller, branched tubes called tracheoles.
What do the tracheoles extend throughout?
The tracheoles extend throughout all the body tissues of the insect
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
The tracheae are supported by strengthened rings to prevent them from collapsing.
The tracheae divide into smaller, branched tubes called tracheoles.
The tracheoles extend throughout all the body tissues of the insect.
In this way, what happens to atmospheric air, with the oxygen it contains?
In this way, atmospheric air, with the oxygen it contains, is brought directly to the respiring tissues
As with all terrestrial organisms, insects have evolved mechanisms to conserve water.
For gas exchange, insects have evolved an internal network of tubes called tracheae.
The tracheae are supported by strengthened rings to prevent them from collapsing.
The tracheae divide into smaller, branched tubes called tracheoles.
The tracheoles extend throughout all the body tissues of the insect.
In this way, atmospheric air, with the oxygen it contains, is brought directly to the respiring tissues, as there is a what?
In this way, atmospheric air, with the oxygen it contains, is brought directly to the respiring tissues, as there is a short diffusion pathway from:
1. A tracheole
to
2. Any body cell
What speed up the rate of diffusion of gases from tracheae into body cells?
- Body movements
Or, - Contractions
speed up the rate of diffusion of gases from tracheae into body cells
What is the name of the gas exchange system in insects?
The name of the gas exchange system in insects is the tracheal system
Why are locusts used in Biology?
Locusts are used in Biology, because they:
- Have a small SA and a relatively large volume
- Have no transport system
- Are easy to see and easy to look at
Locusts are used in Biology, because they have a small SA and a relatively large volume (so a what), have no transport system and are easy to see and easy to look at?
Locusts are used in Biology, because they:
- Have a small SA and a relatively large volume (so a large SA:V ratio)
- Have no transport system
- Are easy to see and easy to look at
What are the different parts of an insect’s body?
The different parts of an insect’s body are the:
- Head
- Wings
- Abdomen
- Thorax
- Tracheae
- Tracheoles
- Spiracles
How many tracheae are there?
There are 2 tracheae
There are 2 tracheae, located where?
There are 2 tracheae, located down either side of the insect’s body
There are 2 tracheae, located down either side of the insect’s body, running how?
There are 2 tracheae, located down either side of the insect’s body, running parallel
The tracheoles are smaller, branched tubes that do what?
The tracheoles are smaller, branched tubes that take the oxygen directly to the muscle:
- Tissues
- Fibres
The tracheoles are smaller, branched tubes that take the oxygen directly to the muscle tissues and fibres, as they’re where?
The tracheoles are smaller, branched tubes that take the oxygen directly to the muscle:
1. Tissues
2. Fibres
,as they’re inside the muscle tissue
Where are the spiracles located?
The spiracles are located outside of the body
The spiracles are located outside of the body.
What do spiracles do, similar to stomata in plants?
Spiracles control water loss, similar to stomata in plants
How do insects take in air?
How does the insect ventilate its body?
The insect pumps the abdomen in and out
How do insects take in air?
How does the insect ventilate its body?
The insect pumps the abdomen in and out, which does what?
The insect pumps the abdomen in and out, which draws air:
1. Into
2. Out of
the tracheae via the spiracles
How do insects take in air?
How does the insect ventilate its body?
The insect pumps the abdomen in and out, which draws air into and out of the tracheae via the spiracles.
It is a really simple system.
Air moves into the tracheoles and arrives where?
Air moves into the tracheoles and arrives directly at the muscle tissue
Insects have a very small what system, but it is very efficient?
Insects have a very small mass transport system, but it is very efficient
What is at the bottom of the tracheoles?
At the bottom of the tracheoles is a small amount of fluid that the oxygen can dissolve in
At the bottom of the tracheoles is a small amount of fluid that the oxygen can dissolve in and thus do what more easily?
At the bottom of the tracheoles is a small amount of fluid that the oxygen can:
- Dissolve in
- Thus diffuse into the muscle fibres more easily
How do insects minimise water loss?
Insects minimise water loss by closing spiracles as often as they can
Insects minimise water loss by closing spiracles as often as they can and they have what around the spiracles?
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to do what?
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to trap humid air
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to trap humid air, which therefore results in what?
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to trap humid air, which therefore results in less water loss
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to trap humid air, which therefore results in less water loss.
If insects need to close the spiracles for a long period of time, some of them have what along the tracheae?
If insects need to close the spiracles for a long period of time, some of them have air sacs along the tracheae
Insects minimise water loss by closing spiracles as often as they can and they have hairs around the spiracles to trap humid air, which therefore results in less water loss.
If insects need to close the spiracles for a long period of time, some of them have air sacs along the tracheae, which allow them to do what?
If insects need to close the spiracles for a long period of time, some of them have air sacs along the tracheae, which allow them to store a small amount of oxygen just in case they can’t ventilate for whatever reason
Respiratory gases move in and out of the tracheal system in how many ways?
Respiratory gases move in and out of the tracheal system in 3 ways:
- Along a diffusion gradient
- Mass transport
- The ends of the tracheoles are filled with water
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, what happens to oxygen?
When cells are respiring, oxygen is used up
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so what falls?
When cells are respiring:
- Oxygen is used up
- So its concentration towards the ends of the tracheoles falls
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so its concentration towards the ends of the tracheoles falls.
What does this create?
This creates a diffusion gradient
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so its concentration towards the ends of the tracheoles falls.
This creates a diffusion gradient that causes what to happen?
This creates a diffusion gradient that causes gaseous oxygen to diffuse from the atmosphere along the:
1. Tracheae
2. Tracheoles
to the cells
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so its concentration towards the ends of the tracheoles falls.
This creates a diffusion gradient that causes gaseous oxygen to diffuse from the atmosphere along the tracheae and the tracheoles to the cells
Carbon dioxide is produced by cells during respiration.
What does this create?
This creates a diffusion gradient in the opposite direction
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so its concentration towards the ends of the tracheoles falls.
This creates a diffusion gradient that causes gaseous oxygen to diffuse from the atmosphere along the tracheae and the tracheoles to the cells
Carbon dioxide is produced by cells during respiration.
This creates a diffusion gradient in the opposite direction.
What does this cause?
This causes gaseous carbon dioxide to diffuse along the:
1. Tracheoles
2. Tracheae
from the cells to the atmosphere
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Along a diffusion gradient:
When cells are respiring, oxygen is used up and so its concentration towards the ends of the tracheoles falls.
This creates a diffusion gradient that causes gaseous oxygen to diffuse from the atmosphere along the tracheae and the tracheoles to the cells
Carbon dioxide is produced by cells during respiration.
This creates a diffusion gradient in the opposite direction.
This causes gaseous carbon dioxide to diffuse along the tracheoles and the tracheae from the cells to the atmosphere.
As diffusion in air is much more rapid than in water, respiratory gases are exchanged how by this method?
As diffusion in air is much more rapid than in water, respiratory gases are exchanged quickly by this method
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Mass transport:
What can squeeze the tracheae that are enabling mass movements of air in and out?
The contraction of muscles in insects can squeeze the tracheae that are enabling mass movements of air in and out
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
Mass transport:
The contraction of muscles in insects can squeeze the tracheae that are enabling mass movements of air in and out.
This further does what?
This further speeds up the exchange of respiratory gases
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, what do the muscle cells around the tracheoles do?
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
What does this produce?
This produces lactate
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (what)?
This produces lactate (lactic acid)
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is what and does what?
This produces lactate (lactic acid), which:
- Is soluble
- Lowers the water potential of the muscle cells
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is soluble and lowers the water potential of the muscle cells.
What does water therefore do?
Water therefore moves into the cells from the tracheoles by osmosis
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is soluble and lowers the water potential of the muscle cells.
Water therefore moves into the cells from the tracheoles by osmosis.
The water in the ends of the tracheoles decreases in volume and in doing so does what?
The water in the ends of the tracheoles decreases in volume and in doing so draws air further into them
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is soluble and lowers the water potential of the muscle cells.
Water therefore moves into the cells from the tracheoles by osmosis.
The water in the ends of the tracheoles decreases in volume and in doing so draws air further into them.
What does this mean?
This means that:
- The final diffusion pathway is in a gas rather than a liquid phase
- Therefore diffusion is faster
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is soluble and lowers the water potential of the muscle cells.
Water therefore moves into the cells from the tracheoles by osmosis.
The water in the ends of the tracheoles decreases in volume and in doing so draws air further into them.
This means that the final diffusion pathway is in a gas rather than a liquid phase and therefore diffusion is faster.
What does this do?
This increases the rate at which air is moved in the tracheoles
Respiratory gases move in and out of the tracheal system in 3 ways - Along a diffusion gradient, mass transport and the ends of the tracheoles are filled with water.
The ends of the tracheoles are filled with water:
During periods of major activity, the muscle cells around the tracheoles carry out some anaerobic respiration.
This produces lactate (lactic acid), which is soluble and lowers the water potential of the muscle cells.
Water therefore moves into the cells from the tracheoles by osmosis.
The water in the ends of the tracheoles decreases in volume and in doing so draws air further into them.
This means that the final diffusion pathway is in a gas rather than a liquid phase and therefore diffusion is faster.
This increases the rate at which air is moved in the tracheoles, but leads to what?
This:
1. Increases the rate at which air is moved in the tracheoles
,but
2. Leads to greater water evaporation
Gases enter and leave tracheae through what?
Gases:
1. Enter
2. Leave tracheae
through tiny pores on the body surface
Gases enter and leave tracheae through tiny pores on the body surface, called what?
Gases:
1. Enter
2. Leave tracheae
through tiny pores on the body surface, called spiracles
Gases enter and leave tracheae through tiny pores on the body surface, called spiracles.
Spiracles may be opened and closed by what?
Spiracles may be:
1. Opened
2. Closed
by a valve
Gases enter and leave tracheae through tiny pores on the body surface, called spiracles.
Spiracles may be opened and closed by a valve.
When the spiracles are open, what can happen?
When the spiracles are open, water vapour can evaporate from the insect
Gases enter and leave tracheae through tiny pores on the body surface, called spiracles.
Spiracles may be opened and closed by a valve.
When the spiracles are open, water vapour can evaporate from the insect.
For much of the time, insects keep their spiracles closed to prevent this what?
For much of the time, insects keep their spiracles closed to prevent this water loss
Gases enter and leave tracheae through tiny pores on the body surface, called spiracles.
Spiracles may be opened and closed by a valve.
When the spiracles are open, water vapour can evaporate from the insect.
For much of the time, insects keep their spiracles closed to prevent this water loss.
Periodically, insects open the spiracles to allow what?
Periodically, insects open the spiracles to allow gas exchange
The tracheal system is an efficient method of gas exchange.
However, it does have some limitations.
The tracheal system relies mostly on what to exchange gases between the environment and the cells?
The tracheal system relies mostly on diffusion to exchange gases between the:
- Environment
- Cells
The tracheal system is an efficient method of gas exchange.
However, it does have some limitations.
The tracheal system relies mostly on diffusion to exchange gases between the environment and the cells.
For diffusion to be effective, the diffusion pathway needs to be short, which is why insects are what?
For diffusion to be effective, the diffusion pathway needs to be short, which is why insects are of a small size
The tracheal system is an efficient method of gas exchange.
However, it does have some limitations.
The tracheal system relies mostly on diffusion to exchange gases between the environment and the cells.
For diffusion to be effective, the diffusion pathway needs to be short, which is why insects are of a small size.
As a result, the length of the diffusion pathway does what?
As a result, the length of the diffusion pathway limits the size that insects can attain
The tracheal system is an efficient method of gas exchange.
However, it does have some limitations.
The tracheal system relies mostly on diffusion to exchange gases between the environment and the cells.
For diffusion to be effective, the diffusion pathway needs to be short, which is why insects are of a small size.
As a result, the length of the diffusion pathway limits the size that insects can attain.
Being small hasn’t hindered insects.
Insects are one of the most what groups of organisms on Earth?
Insects are one of the most successful organisms on Earth
