3A Exchange and Transport Systems Flashcards
Figure 1 shows the filament of the fish.
Fill in the labels:
https://media.discordapp.net/attachments/352951793187029005/805146275426074634/unknown.png
A = Lamella
B = Capillary
C = Water flow
D = Gill Filament
In a fish’s lamella, the flow of blood is located where?
Capillary
In a fish’s gill filaments, the flow of water is left. What is the direction of the flow of blood?
Right
List two features the gill filament has and how it helps the fish with gas exchange.
The lamella on the gill filament give it a high surface area to volume ratio, increasing the rate of gas exchange.
The gill filament uses a countercurrent system which means that blood cells can become fully oxygenated despite getting oxygen by diffusion.
Explain how a countercurrent system leads to blood cells which are fully oxygenated.
In the gill filament of a fish, water flow is opposite to the flow of the blood.
The reason for this is because, as blood goes down the capillaries, it will constantly find new oxygenated water cells coming from the other side and so a constant concentration gradient is established, meaning blood cells do not reach equilibrium with the water until it becomes fully oxygenated, to which it can be sent to the rest of the body.
Explain how a system where water flow is the same direction as blood flow leads to blood cells only having the potential to get about 50% oxygen content by diffusion.
What are the consequences of this if it were to be true for the fish?
If, in the gill filament of a fish, water flow is the same direction as blood flow, blood travels down the capillary and a concentration gradient is not constant and eventually decreases.
Since the concentration gradient between the blood and water decreases as you go across the lamella, this means the rate of oxygen exchange will decrease meaning that blood can only have a maximum of 50% oxygen content.
This can be dangerous to the fish, as less oxygen will be delivered to their cells meaning the fish may suffer from tiredness that may turn extreme.
Name A and name B:
https://media.discordapp.net/attachments/352951793187029005/805151433099575306/unknown.png
A = Water B = Blood
In insects, what are tracheae?
Tracheae are microscopic, air-filled pipes used for gas exchange.
In insects, what are spiracles?
Spiracles are small, circular pores on insects which supply air into tracheae.
In insects, what are tracheoles, and how are they adapted to deliver diffusion quickly?
As well as this, cells have a product of carbon dioxide which must be removed during respiration. How do they get released?
Tracheoles are branches which sprouted off tracheae that are responsible to deliver oxygen to respiring cells.
Tracheoles are one cell thick which means that the diffusion pathway is very short meaning gas exchange occurs faster.
In insects, carbon dioxide, once released, moves down it’s own concentration gradient to the spiracles to be released to the atmosphere.
How do insects move air in and out the spiracles?
Insects have rhythmical abdominal movements which allow the movement of gases in and out the insect.
Name A,B and C.
https://media.discordapp.net/attachments/352951793187029005/805160065794703370/unknown.png
A = Spiracle
B = Tracheae
C = Tracheole
List features of the insect which help the insect control water loss.
Spiracles can open and close, and so when they close the rate of water loss will be lower as they have less places to escape from.
There is a waxy, waterproof cuticle around the insect, which lowers the rate of evaporation.
There are hairs on the spiracles which trap water.
What is the main part of the plant cell responsible for gas exchange?
Mesophyll
Explain an adaptation of spongy mesophyll and how this adaptation allows the plant to have faster gas exchange.
Spongy Mesophyll often feature large spaces of empty air.
These spaces allow oxygen and carbon dioxide to diffuse in and out of the leaves easily.
What part of the plant cell lets gases in and out?
Stomata
Stomata = plural, stroma = singular
Where are stomata located?
The epidermis
What allows stomata to open or close?
Guard cells
How do stomata close when water concentration gets low, and how do stomata open when water concentration gets high?
Guard cells control the entry of gases into the stroma physiologically.
For example, when water concentration is high in the stroma, guard cells will become turgid and will enter the stomata by osmosis, opening up the stroma.
However, when water concentration is low in the stroma, guard cells will become flaccid and will leave the stomata by osmosis, closing the stroma.
Explain the features of the waxy cuticle in insects and plants and how it helps to prevent water loss.
A waxy cuticle is a layer which is on top of the epidermis in plants and on top of insects. It is waterproof and thick and so water loss becomes harder as any that evaporate will find it harder to leave the organism.
The waxy cuticle also has hairs which are mostly present in insects and xerophytic plants which trap moist air. In xerophytic plants, the ability to trap moist air means that there is less water loss by osmosis as the concentration gradient is lower than dry air.
In insects, hairs on the waxy cuticle basically share the same purpose near spiracles.
List 3 features of xerophytic plants which allow them to survive in hot, dry and windy conditions.
Xerophytic plants are curled up, which traps moist air as the collision and entry of dry air is much less likely. Due to this, xerophytic plants will lose less water from the stomata being open as there is a lower concentration gradient between the moist air and the water in the stomata.
Xerophytic plants have many hairs on their waxy cuticle near stomata which allow the trapping of moist air, which again decreases the concentration gradient.
Xerophytic plants have a reduced number of stomata so when they are open less water loss is caused all together.
Waxy, waterproof cuticles on leaves reduces evaporation.
What is the formula for volume in a cube?
x^3
This is because all the sides in a cube are equal so we can account them for the same algebraic expression.
x = cube measurement (e.g. 4 cm)
What is the formula for surface area in a cube?
6(x^2)
Assuming the cube has 6 sides.
x = cube measurement (e.g. 4 cm)
It is squared because all the sides in a cube are equal so 2^2 = 2x2 etc
The link given is a picture of a cube:
https://media.discordapp.net/attachments/352951793187029005/805174454710960249/unknown.png
Give the surface area and volume.
Find the surface area to volume ratio.
Volume = 4^3 = 64
Surface area = 6(4^2) = 6(16) = 96
1.5:1
Divide both sides by volume to get the surface area to volume ratio.
64 / 64 = 1
96 / 64 = 1.5