Transport Flashcards
What does the xylem transport?
Water and dissolved mineral ions
Explain how plants absorb water and transport the water to their leaves
1) water moves into the root hair cell via osmosis
2) the water continues to diffuse along the cell from a dilute solution to a concentrated solution until it eventually reaches the xylem
3) water then gets sucked up to the leaves in the transpiration stream
What is transpiration?
The evaporation of water from the surface of a plant
What is the xylem made up of?
Lignifies cells which are very strong so can withstand the high pressure
How does high humidity affect the rate of transpiration?
1) decreases the rate of transpiration
2) decreases the concentration gradient
How does light intensity affect the rate of transpiration?
When it is light the guard cells surrounding the stomata fill with water, opening the stomata and when it is dark they become flaccid closing the stomata
How does high temperature affect the rate of transpiration?
1) increases the rate of transpiration
2) water particles have more kinetic energy so there is more evaporation
How does increased wind affect the rate of transpiration?
1) increases the rate of transpiration
2) increases the concentration gradient as moves moist air away
Describe an experiment to investigate the role of environmental factors on the rate of transpiration
Use a potometer to measure the rate of uptake of water (the time taken for the air bubble to move along the scale is measured and the plant can be exposed to different conditions to see how this affects the rate of transpiration)
Why do unicellular organisms not require a transport system?
They have a very high surface are to volume ratio so materials can simply diffuse in and out of the cell
What is the plasma?
The liquid part of the blood (mainly composed of water)
How are red blood cells adapted to store oxygen?
1) biconcave shape to increase surface area
2) no nucleus to increase capacity for haemoglobin
3) thin cell surface membrane to increase the rate of diffusion
What is the function of the plasma?
1) Carries the blood cells, dissolved nutrients, carbon dioxide and urea around the body
2) distributes heat around the body
What is the function of red blood cells?
To transport oxygen around the body (load in the lungs and unload in other parts of the body)
What is the compound formed when oxygen bonds with haemoglobin?
Oxyhaemoglobin
What is the function of lymphocytes?
1) produce antibodies to destroy microorganisms
2) memory lymphocytes provide immunity to certain diseases
What is the function of phagocytes?
To engulf and digest bacteria and other microorganisms which have entered the body
What do antibodies stick to?
Antigens on the surface of pathogens
How do antibodies destroy pathogens?
1) make the pathogens stick together so the phagocytes can engulf them more easily
2) act as a label so the phagocytes can recognise the pathogen more easily
3) cause the bacterial cell to burst open
4) neutralise toxins produced by the bacteria
What are platelets?
Small fragments of other cells
What happens in a double circulatory system?
1) pulmonary circulation (blood piped to lungs to pick up oxygen)
2) systemic circulation (heart pumps oxygenated blood around the body)
What happens in a single circulatory system?
Blood is pumped from the heart to the gas exchange organ and then directly to the rest of the body
Why are double circulatory systems better?
A higher blood pressure can be maintained meaning that blood travels more quickly to the organs
Give an example of an organism with a single circulatory system
Fish
What so the name of the blood vessel which goes from the heart to the lungs?
Pulmonary artery
What so the name of the blood vessel which goes from the heart to the liver?
Hepatic artery
What so the name of the blood vessel which goes from the heart to the kidneys?
Renal artery
What so the name of the blood vessel which goes from the liver to the heart?
Hepatic vein
What so the name of the blood vessel which goes from the kidneys to the heart?
Renal vein
What so the name of the blood vessel which goes from the lungs to the heart?
Pulmonary vein
What so the name of the blood vessel which goes from the heart?
Aorta
What so the name of the blood vessel which goes to the heart?
Vena cava
How does the heart pump blood around the body?
Through a series of contractions of the cardiac muscle (called the cardiac cycle)
What is it called when the cardiac muscle is contracting?
The heart is in systole
What is it called when the cardiac muscle is relaxing?
The heart is in diastole
How is the heart rate increased?
1) sensors in the carotid artery detect the increase in carbon dioxide produced by the muscles when exercising
2) they send nerve impulses to the medulla
3) the medulla sends nerve impulses along the accelerator nerve in rider to increase the heart rate
4) when carbon dioxide production decreases the medulla receives less impulses and sends impulses down the decelerator nerve in order to slow down the heart rate
What are the arteries?
Blood vessels which carry blood from the heart to other organs of the body
What is the difference between veins and arteries?
1) blood is under lower pressure in the veins
2) veins have a larger lumen
3) veins have thinner walls
4) veins have valves to prevent the back flow of blood
What are the capillaries?
Blood vessels which carry blood through the organs and are the site of exchange of materials with cells so their walls are one cell thick to maximise the rate of diffusion
How does coronary heart disease cause death?
1) blocked/narrowed/clogged
2) coronary artery
3) clot
4) fat/cholesterol
5) less blood to heart
6) less oxygen
7) less aerobic respiration
8) lactic acid
9) heart attack
What chamber of the heart does the aorta connect to?
The left ventricle
What chamber of the heart does the pulmonary vein connect to?
The left atrium
What chamber of the heart does the vena cava connect to?
The right atrium
What chamber of the heart does the pulmonary artery connect to?
The right ventricle
Does blood flow from the atrium to ventricles or ventricles to atrium in the heart?
Atrium to ventricles
What are the names of valves in the heart?
Antrioventricular valve
Describe how to measure heart rate
1) place fingers on artery
2) count pulse
Describe the difference between a human and fish heart
1) fewer chambers
2) fewer valves
3) no septum (no separation of left and right sides)
4) fewer blood vessels
What is the bit which divides the left and right side of the heart called?
The septum
Why is the pressure returning to a fish heart under lower pressure than that returning to a human heart?
1) fish have smaller hearts
2) single circulation
On which side of the heart is the muscular wall thicker?
The left (as it has to pump blood all the way around the body)
what does the phloem transport?
sucrose and amino acids
how do vaccinations provide artificial immunity?
they result in the manufacture of memory cells, which enables future antibody production to the pathogen to occur sooner, faster and in greater quantity
what are the stages of a vaccination?
1) the body is injected with a weakened or dead pathogen
2) the body responds by producing antibodies to the antigens of the pathogen and memory cells
how do platelets work?
1) Exposure to air stimulates platelets to produce a chemical which causes the soluble fibrinogen to change into insoluble fibrin.
2) Fibrin forms a clot around cut preventing further blood loss and the entry of pathogens.
what are platelets?
small fragments of other cells
Suggest how dehydration increases the risk of a heart attack
1) less water in blood
2) increase concentration of blood
3) increase blood pressure
Why is a pulmonary embolism (blockage) a heath risk?
1) less blood to lungs
2) less gas exchange (less oxygen in blood)
How do vaccinations protect organisms from disease?
1) dead pathogen
2) antigens
3) memory cells
4) secondary immune response (antibodies produces faster)
Describe what happens to muscle cells if cholesterol builds up in the artery which supplies blood to them
1) less supply of glucose / oxygen
2) less aerobic respiration
3) more anaerobic respiration
4) less energy
5) lactic acid
6) enzymes denature
7) muscle cells die
Explain how the structure of a capillary is adapted to help improve heart function?
1) thin/one cell thick
2) permeable
3) faster diffusion
why is transpiration important to plants?
1) supply mineral ions
2) support / turgidity / prevent wilting
3) cooling / prevent overheating;
4) water for photosynthesis;
Suggest why it is important to have blood that clots
1) less blood loss
2) less entry of pathogens
