Module 3.1 - Exchange and Transport Flashcards
1
Q
Why do organisms need to exchange things with their environment? (2)
A
- Organisms need oxygen and glucose for metabolic activities
- Organisms need to excrete waste products
2
Q
What does the rate of exchange depend on? (1)
A
- Organism’s surface area to volume ratio (SAV)
3
Q
How to calculate SA:V? (1)
A
- Divide the surface area by the volume
4
Q
Why do single-celled organisms not need exchange surfaces? (2)
A
- Substances can diffuse across the cell surface membrane
- Diffusion rate is quick because the distance of travel is small
5
Q
Why do multicellular organisms need exchange surfaces? (4)
A
- Diffusion across the outer membrane is too slow
- Big distance between cells within the body and the outside environment
- Low surface area to volume ratio
- High metabolic rate
6
Q
Adaptation of root hair cells? (1)
A
- Large surface area which increases the rate of transport mechanisms
7
Q
Adaptations of alveolus? (6)
A
- Made of a single layer of thin, flat cells called the alveolar epithelium
- Decrease the distance for the diffusion of O2 and CO2
- Surrounded by a large capillary network
- The blood takes O2 and CO2 to and from the alveoli
- Well ventilated
- Help to maintain concentration gradients of O2 and CO2
8
Q
Adaptations of fish gills? (4)
A
- Gills are the gas exchange surface in fish
- Has a large network of capillaries
- Well ventilated - fresh water passes over them
- Help to maintain concentration gradients of O2 and CO2
9
Q
Structure of the lungs? (2)
A
- Trachea → bronchi → bronchioles → alveoli
- The ribcage, intercostal muscles and diaphragm work together to move air in and out
10
Q
Goblet cells? (2)
A
- Lines the airways
- Secrete mucus
11
Q
Mucus? (2)
A
- Traps microorganisms and dust particles in the inhaled air
- Stops them from reaching the alveoli
12
Q
Cilia? (4)
A
- Beat the mucus
- Waft the mucus upward and away from the alveoli towards the throat
- Mucus is swallowed
- Prevent lung infections
13
Q
Elastic fibres? (4)
A
- Found in the walls of the trachea, bronchi, bronchioles and alveoli
- Help the process of breathing out
- On breathing in, the lungs inflate and the elastic fibres are stretched
- The fibres recoil to help push the air out when exhaling
14
Q
Smooth muscle? (2)
A
- Found in the walls of the trachea, bronchi and bronchioles
- Allows their diameter to be controlled
15
Q
Rings of cartilage? (4)
A
- In the walls of the trachea and bronchi
- Provides support
- Strong but flexible
- Stops the trachea and bronchi collapsing when breathing and pressure drops
16
Q
Trachea? (5)
A
- Large C-shaped cartilage
- Smooth muscle
- Elastic fibres
- Goblet cells
- Ciliated epithelium
17
Q
Bronchi? (5)
A
- Smaller pieces of cartilage
- Smooth muscle
- Elastic fibres
- Goblet cells
- Ciliated epithelium
18
Q
Larger bronchiole? (4)
A
- Smooth muscle
- Elastic fibres
- Goblet cells
- Ciliated epithelium
19
Q
Smaller bronchiole? (3)
A
- Smooth muscle
- Elastic fibres
- Ciliated epithelium
20
Q
Smallest bronchiole? (2)
A
- Elastic fibres
- No cilliated epithelium
21
Q
Alveoli? (2)
A
- Elastic fibres
- No ciliated epithelium
22
Q
Inspiration? (7)
A
- External intercostal and diaphragm muscles contract
- Ribcage moves upwards and outwards
- Diaphragm flattens
- Volume of the thorax increases
- Lung pressure decreases to below atmospheric pressure
- Air flows into lungs
- Inspiration requires energy
23
Q
Expiration? (6)
A
- External intercostal and diaphragm muscles relax
- Ribcage moves downwards and inwards
- Diaphragm curves
- Volume of the thorax decreases
- Lung pressure increase to above atmospheric pressure
- Air flows out of lungs
24
Q
Forced expiration? (2)
A
- Internal intercostal muscles contract
- Ribcage is pulled down and in
25
Q
Tidal volume (TV)? (2)
A
- Volume of air in each breath
- Usually about 0.4 dm³
26
Q
Vital capacity? (1)
A
- Maximum volume of air that can be breathed in or out
27
Q
Breathing rate? (1)
A
- How many breaths are taken in a minute
28
Q
Oxygen consumption/ oxygen uptake? (1)
A
- Rate at which an organism uses up oxygen
29
Q
Spirometer? (1)
A
- A machine that can give readings of tidal volume, vital capacity, breathing rate and oxygen uptake
30
Q
How does a spirometer work? (8)
A
- Spirometer has an oxygen-filled chamber with movable lid
- Person breathes through tube connected to oxygen chamber
- Person breathes in and out lid of chamber moves up and down
- Movements recorded by pen attached to the lid writes on a rotating drum
- A spirometer trace is made
- Spirometer can be hooked to a motion sensor that use movements to produce electronic signals
- Electron signals are picked up by a data logger
- Soda lime in the tube the subject breathes into absorbs CO2
31
Q
Use of soda lime? (2)
A
- Air that’s breathed out is a mixture of O2 and CO2
- CO2 is absorbed by soda lime so there’s only oxygen in the chamber
32
Q
How to analyse a spirometer trace? (4)
A
- Breathing rate: number of peaks in the first minutes
- Tidal volume: difference in height of the peaks
- Vital capacity: difference in height of the largest peak
- Oxygen consumption: gradient of the slope, should be negative
33
Q
Gill? (7)
A
- Gill filaments/ primary lamellae - thin branches
- Gill filaments increase surface area for gas exchange
- Gill filaments covered in gill plates/ secondary lamellae
- Gill plates increase surface area even more
- Gill plates have lots of blood capillaries to increase diffusion
- Gill plates have thin surface layer of cells to increase diffusion
- Each gill is supported by a gill arch
34
Q
Counter-current system? (5)
A
- Water enters fish through mouth and passes out through gills
- Blood flows through the gill plates in one direction
- Water flows over in the opposite direction
- Concentration of oxygen in water is higher than in blood
- Oxygen diffuses from the water into the blood
35
Q
Water entering during fish ventilation? (5)
A
- Fish opens its mouth
- Floor of buccal cavity lowers
- Volume of buccal cavity increases
- Pressure decreases inside the cavity
- Water enters cavity
36
Q
Water leaves during fish ventilation? (5)
A
- Fish closes its mouth
- Floor of buccal cavity rises
- Volume of buccal cavity decreases
- Pressure increases inside cavity
- Water leaves cavity across the gill filaments
37
Q
Role of operculum? (3)
A
- A bony flap that covers and protects the gills
- Increase in pressure from water leaving gills forces operculums to open
- Allows water to leave the gills
38
Q
Gas exchange in insects? (7)
A
- Insects have trachea for gas exchange
- Air through spiracles
- Trachea → tracheoles
- Tracheoles has thin permeable walls
- Tracheoles contain fluid
- O2 diffuse down concentration gradient through fluid into body cells
- CO2 diffuses in the opposite direction
39
Q
How do insects mechanically move air in and out? (2)
A
- Use rhythmic abdominal movements to change volume of bodies to move air through spiracles
- Larger insects fly and use wing movements to pump their thoraxes
