B4 - Organising animals and plants Flashcards
What is blood?
A tissue consisting of plasma, red blood cells, white blood cells and platelets.
What is the function of the red blood cell?
Carries oxygen from the lungs to every cell in the body.
How are red blood cells adapted to their function?
Large surface area
Have no nucleus
Contains haemoglobin which oxygen binds to easily
Why does a red blood cell not have a nucleus?
More space for haemoglobin to carry more oxygen.
What is haemoglobin called when it’s joined with oxygen?
Oxyhaemoglobin
What is the function of the white blood cells?
To defend the body against pathogens.
What are the two different types of white blood cells?
Lymphocytes and phagocytes.
What type of white blood cell engulfs microbes?
Phagocyte
What do lymphocytes produce to defend the body against infection?
Anti-bodies and anti-toxins
What is the function of platelets?
Help blood clot around a wound to prevent microorganisms getting in.
Which component of blood carries cells and other dissolved substances?
Plasma
What substances are carried in the blood plasma?
Carbon dioxide, hormones, glucose, amino acids, urea, proteins, antibodies, antitoxins
What is the function of the valves in the heart?
To prevent the back flow of blood.
How do you calculate the rate of blood flow?
Rate of blood flow (ml/min) = volume of blood (ml) / number of minutes (min)
What are the three types of blood vessels?
Artery, vein, capillary
Which blood vessel carries blood away from the heart?
Artery
Which blood vessel carries blood towards the heart?
Vein
What is the lumen?
The space inside the blood vessel.
Describe the structure of a capillary.
The wall is only one cell thick and very small lumen.
Why do capillaries have a small lumen and a wall that is only one cell thick?
To allow substances to diffuse in and out very easily.
Describe the structure of an artery.
Very thick walls made of smooth muscle with elastic fibres and a small lumen.
Why does an artery have thick muscular walls and elastic fibres?
Smooth muscle gives strength due to high pressure of the blood
Elastic fibres allow the artery to stretch and spring back
Describe the structure of a vein
Thinner
less muscular walls than arteries
large lumen
contain valves
Why do veins have thin walls with a large lumen?
Pressure of the blood is lower so thick walls are not needed
Larger lumen helps the blood to flow
Why do veins have valves?
To stop blood flowing in the wrong direction.
Identify the structure of the heart.
A = vena cava B = right atrium C = right ventricle D = left ventricle E = valves F = left atrium G = pulmonary vein H = aorta I = pulmonary artery
How many chambers does the heart have and what are they?
4 chambers, Atria and ventricles.
Which side of the heart carries oxygenated blood?
Left.
Which side of the heart carries deoxygenated blood?
Right
Which blood vessel carries blood to the right atrium?
Vena cava
Where does the vena cava carry blood from?
The body
Which blood vessel carries blood away from the left ventricle and where does it go?
Aorta to the body.
Which side of the heart is made from thicker muscles and why?
Left, to pump blood all the way around the body at high pressure.
Which blood vessel returns blood to the left atrium?
Pulmonary vein
Where does the pulmonary artery carry blood from?
The lungs
Why does the heart pump blood to the lungs?
For gas exchange.
Which blood vessel carries blood from the right ventricle and where does it go?
Pulmonary artery to the lungs.
What are the coronary arteries?
Blood vessels that supply the hearts muscle tissue with oxygen.
Where is the hearts pacemaker found and what is its function?
Group of cells in the right atrium controlling heat rate.
What is the role of an artificial pacemaker?
To correct irregularities in the heart rate.
What is cardiovascular disease?
Diseases of the heart and the blood vessels.
What is coronary heart disease?
Layers of fatty material build up inside the coronary arteries, narrowing them.
Why is blocking the coronary artery a problem?
Blood flow is reduced to the heart therefore reduces the supply of oxygen for the heart muscle.
How can CHD be treated?
Stents and statins.
How do stents treat CHD?
Reopens the blocked coronary artery, restoring blood flow.
What are the advantages of using stents to treat CHD?
Effective for a long time and quick recovery time after surgery.
What are the disadvantages of using stents to treat CHD?
Risk of complication or infection during the operation.
Possible risk of blood clots near the stent.
What can happen to the heart valves if they become faulty?
Not open fully or develop a leak.
What are the consequences of a faulty heart valve?
Blood may flow in both directions in the heart meaning it doesn’t circulate as effectively.
Name 2 sources of replacement heart valves.
Mechanical or biological.
Name a risk associated with surgical intervention in treating heart disease.
Infections
complications (eg. a heart attack and development of a blood clot)
When would an artificial heart be used?
To allow the heart to rest and recover and keep the patient alive whilst they wait for a transplant.
What are the advantages of having an artificial heart transplant?
Less likely to be rejected by the body.
What are the disadvantages of using an artificial heart to treat CHD?
Parts could wear out
The electric motor could fail
Blood moves through less smoothly leading to blood clots and strokes.
How do statins treat CHD?
Decreases blood concentration of cholesterol, which reduces the build up of fatty deposits in the coronary arteries.
What are the advantages of using statins to treat cardiovascular diseases?
Reduces risk of strokes and heart attacks
Increases good cholesterol
Decreases bad cholesterol and so reduces fatty deposit formation
What are the disadvantages of using statins to treat cardiovascular diseases?
Could forget to take them long term Side effects (eg. headaches, kidney failure, liver damage and memory loss) Not instantly effective
Name a treatment used in the case of total heart failure.
Heart transplant.
Label the main structures in the respiratory system.
(remember to add diagram thingy with answers)
What is the function of the alveoli?
Increase surface area of the lungs to maximise gas exchange.
What is the function of the trachea?
Carries air to and from the lungs.
What is the function of the bronchus?
Carries air into and out of the left or right lung.
How are alveoli adapted to make gas exchange rapid and effective?
Spherical shape
Very thin walls
Lots of capillaries
Why does an alveolus have spherical shape?
To give a large surface area.
Why does an alveolus have very thin walls?
Gives a short diffusion distance for gas to travel in and out of the alveoli.
Why are alveoli surrounded by lots of capillaries?
To provide a good blood supply to maintain a steep concentration gradient.
What happens to the volume and pressure inside the chest when inhale?
Volume increases, pressure decreases
What happens to the volume and pressure inside the chest when we exhale?
Volume decreases, pressure increases.
What are the main tissues of a plant?
Epidermal tissues, palisade mesophyll, spongy mesophyll, xylem and phloem, meristem.
What is the function of epidermal tissues?
Covers the surfaces of the leaf and provides protection.
How are epidermal tissues adapted to carry out their function?
Secretes a waxy substance that waterproofs the surface of the leaf.
What is the function of palisade mesophyll tissues?
Main site of photosynthesis.
How are palisade mesophyll tissues adapted to carry out their function?
Contains lots of chloroplasts in palisade cells
What is the function of spongy mesophyll tissues?
Allows the diffusion of gases
How are spongy mesophyll adapted to carry out their function?
Has large air spaces and a large surface area to make the diffusion of gases easier
What are the 3 organs for the plant transport system?
Leaves, stems and roots.
What is the function of xylem?
Transports water and dissolved mineral ions
How are xylem adapted to carry out their function?
They are composed of hollow tubes strengthened by lignin.
What is translocation?
The movement of sugars from the leaves to the rest of the plant.
What is the function of phloem?
Transports dissolved food from the leaves around the plant
How are phloem adapted to carry out their function?
Elongated cells with pores in the end cell walls to allow cell sap to move from one phloem cell to the next.
What is the function of a root hair cell?
To absorb water by osmosis and minerals by active transport
How are root hair cells adapted to carry out their function?
Increases the surface area of the root
What is the role of stomata and guard cells?
To control gas exchange and water loss.
When do stomata open?
When the plant has lots of water
When do stomata close?
When the plant is short of water.
What is transpiration?
The movement of water from the roots to the leaves, eventually leaving the leaves via evaporation.
How does temperature effect the rate of transpiration in a plant?
The warmer it is, the faster transpiration happens. When it’s warm the water particles have more energy to evaporate out of the stomata.
How does humidity effect the rate of transpiration in a plant?
The drier the air around a leaf, the faster transpiration happens.
Humidity increases the amount of water outside the leaf, so the concertation gradient between inside and outside the leaf is smaller.
How does air movement effect the rate of transpiration in a plant?
The stronger the wind, the greater the transpiration rate.
Wind moves water particles away from the leaf, maintaining a steep concentration gradient for diffusion.
How does light intensity effect the rate of transpiration in a plant?
The brighter it is, the greater the transpiration rate. Photosynthesis doesn’t happen in the dark so stomata close, meaning less water escapes.
What is a potometer?
A piece of apparatus to measure the rate of transpiration.
