Exchange and Transport Systems-Topic 3A Flashcards
Why do all aerobic organisms require a constant supply of oxygen?
To release energy in the form of ATP.
What is another word for breathing?
Ventilation
What is another word for inhalation and exhalation
inspiration and expiration
Name the 3 muscles responsible for movement in the lungs
Diaphragm
Internal intercostal muscles
External intercostal muscles
What do organisms need to exchange substances with?
Their environment
Cells need to take in …… and ……..
Cells need to take in oxygen ( for aerobic respiration) and nutrients.
Cells need to excrete … …. like ….. and ……
Cells need to excrete waste products like carbon dioxide and urea
Most organisms need to stay roughly the same …………. so ….. needs to be exchanged too
Most organisms need to stay roughly the same temperature so heat needs to be exchanged too.
Will bigger or smaller animals have a higher surface area to volume ratio?
Smaller animals have a higher SA:V ratio.
What does an organism need to supply to every one of its cells for respiration?
Glucose and oxygen.
Why do organisms need to remove waste products?
To avoid damaging itself
In what type of organism can substances diffuse directly into or out of the cell?
Single-celled organisms
Why is diffusion across the outer membrane too slow?
Some cells are deep within the body so there’s a big difference between them and outside environment
Low SA:V ratio so cannot exchange enough substances to supply a large volume of animal through small outer surface
What is mass transport?
A system to carry substances to and from their individual cells
Give examples of behavioural and physiological adaptations
Hippos spend lots of time in the water to help them lose heat
Smaller animals have thick fur or hibernate when weather gets cold.
If an animal is more compact what does this mean surrounding its adaptations?
minimising heat loss e.g. through small ears.
Why does a small mammal need a relatively high metabolic rate compared to a large mammal?
bigger sa:v ratio so heat lost more easily so higher metabolic rate to generate enough heat to maintain a constant body temperature
what are the specialised surfaces mammals evolved to ensure efficient gas exchange?
Lungs
How can the ribs be moved?
By the muscles between them
What are the lungs?
Specialised organs for gas exchange made of bronchioles and alveoli
What is the trachea?
Flexible airways supported by rings of cartilage (windpipe)
What are bronchi?
Two divisions of the trachea each leading to 1 lung. They produce mucus to trap dirt.
What are bronchioles?
Smaller tubes of the bronchi. They control the flow of air into and out of alveoli
What are alveoli?
small “air sacs” where gases are exchanged.
In humans gas exchange happens in the…….
Alveoli
How are the alveoli adapted for gas exchange?
Thin exchange surface (one cell thick) resulting in short diffusion pathway
A large surface area- due to large number of alveoli.
Also a steep conc grad of oxygen and carbon dioxide between alveoli and capillaries
What are bronchioles?
Smaller tubes of the bronchi. They control the flow of air into and out of alveoli
What are alveoli?
small “air sacs” where gases are exchanged.
In humans gas exchange happens in the…….
Alveoli
How are the alveoli adapted for gas exchange?
Thin exchange surface (one cell thick) resulting in short diffusion pathway
A large surface area- due to large number of alveoli.
Also a steep conc grad of oxygen and carbon dioxide between alveoli and capillaries
Why would the specialised exchange surfaces often be found inside an organism?
They are thin for increased diffusion rate however this means they will easily break so are inside organisms for protection.
What have insects evolved for gas exchange?
An internal network of tubes called tracheae which divide into tracheoles.
What does gas enter and leave via in insects?
Pores called spiracles
Spiracles are usually …… to prevent …….
Spiracles are usually closed to prevent water loss.
How does gas exchange in single celled organisms work?
They have a large SA:V ratio and oxygen absorbed by diffusion across their body surface (cell surface membrane)
What is the use of gill lamellae?
To increase the surface area of the gills.
What is countercurrent flow?
Blood and water flow over the gill lamellae in opposite directions therefore maintaining a constant diffusion gradient
What is parallel flow?
The flow of blood and water over the gill lamellae is in the same direction therefore a diffusion gradient is only maintained across part of the length of gill lamellae
How is countercurrent flow more efficient than parallel flow?
As 80% of oxygen available is absorbed compared to 50% of the oxygen available absorbed
A student produced sucrose solutions with different concentrations from a concentrated solution. Name the method she would have used to produce these sucrose solutions.
Dilution series.
Explain advantages of lipid droplets
Lipid droplets increase surface areas for lipase action.
Makes hydrolysis faster.
Name 3 features that increase the rate of diffusion
Large surface area.
Thin (short diffusion pathway)
Maintaining a steep concentration gradient.
Blood enters the lamella with ….. oxygen conc and leaves with ….. oxygen conc
Blood enters the lamella with a low O2 conc and leaves with a high O2 conc.
Name 3 ways which insects minimise water loss
close their spiracles
waterproof waxy cuticle all over their body
tiny hairs around spiracles reducing evaporation.
what is a xerophyte?
a plant specially adapted for life in warm,dry or windy habitats.
give examples of adaptations some plants have to conquer heat loss
Hairs on epidermis (to trap moist air) Stomata sunk in pits to trap moist air which reduces the conc of water between leaf and air. Curled leaves with stomata inside Reduced number of stomata Waxy, waterproof cuticles.
Describe a method you could use to find the surface area of a leaf
Draw around leaf on graph paper
Count squares
Multiply by 2 (for upper and lower leaf surface)
What is the function of the coronary arteries?
To carry oxygen to the heart muscle.
The rise and fall in blood pressure in the aorta is greater than in the small arteries. Suggest why.
Aorta pressure is higher, has elastic tissue for stretch and recoil.
