Chapter B4- Organising Animals And Plants Flashcards
What are the components of blood?
Plasma
Red blood cells
White blood cells
Platelets
What colour is blood plasma?
A yellow liquid
What does plasma do?
Transports all of your blood cells and some other substances around your body
Give an example of other substances plasma carries
Waste carbon dioxide is carried to the lungs
Urea formed in the liver is carried to your kidneys
What do red blood cells do?
Pick up oxygen from the air in your lungs and carry it to the cells where it is needed
Name an adaptation of red blood cells
They are biconcave discs for a larger surface area
They are packed with haemoglobin that binds to oxygen
They have no nucleus, making more space for haemoglobin
What do white blood cells do?
They are part of your bodies defence system against harmful microorganisms
What do platelets do?
Help the blood to clot if you are wounded- this means you will not bleed to death. It also protects you from harmful bacteria entering your body with a scab over the harmed area.
What are the three main types of blood vessels?
Arteries, veins and capillaries
What do arteries do?
Carry blood away from your heart to the organs around your body
What colour is the blood in arteries?
Bright red- oxygenated
What are the traits of an artery?
Arteries have thick walls containing muscles and elastic fibres
They stretch as the blood goes through them and go back into shape afterwards (pulse)
Why is it dangerous if an artery is cut?
As the arteries are under pressure, blood will squirt out each time your heart pumps which is a large problem as you will eventually die of blood loss
What do veins do?
The veins carry blood away from the organs towards your heart
What is the colour of the blood in veins?
Blue- deoxygenated
What are traits of a vein?
They have much thinner walls than arteries and often have valves to prevent the backflow of blood
What do valves do?
if blood tries to flow backwards due to the skeletal muscles then the valves close preventing backflow
What do capillaries do?
Capillaries link arteries and veins
What are the traits of capillaries?
Capillaries have thin walls and are very narrow
Why do capillaries have thin walls?
To enable substances such as oxygen to diffuse easily out of the blood and into your cells.
What is a double circulatory system?
One transport system carries blood to the heart, then lungs then back again
Another carries blood from your heart to the other organs of your body
What does your heart do?
Pump blood around the body
What are the walls of your heart made up of?
Muscle
Explain the process of the pumping of blood in the heart
Deoxygenated blood enters the right side of the heart through the veins cava, into the right atrium. The tricuspid valve pumps this through to the right ventricle. The pulmonary vein then carries this blood to the lungs where it becomes oxygenated. Then the pulmonary vein carries the blood to the left atrium, where the bicuspid valve pumps it through to the left ventricle. Finally the aeorta takes the blood from the left ventricle, and pumps it to the rest of the body
What does the term oxygenated blood mean?
More oxygen, less carbon dioxide
What does the term deoxygenated blood mean?
More carbon dioxide, less oxygen
Which side of the ventricles walls are thicker and why?
The left as they are pumping blood all around the body, whilst the right are only pumping to the lungs
Why do ventricles have thicker walls than atrias/atriums?
Because they pump blood around the body, whilst the atrias only pump blood through the valves through to the ventricles
What happens when someone has coronary heart disease?
The heart muscle becomes too narrow, commonly due to a build up of fatty material. If the blood flow is reduced, then the supply of oxygen is also reduced, resulting in pain, a heart attack or even death.
How can coronary heart disease be solved?
A stent- small metal mesh is placed in the artery. A tiny balloon is then I faked to open up the blood vessel and the stent at the same time. The ballon is removed, but the stent remains, holding the artery open.
A bypass surgery- replacing the blocked arteries with parts of veins from other parts of the body. This is expensive and risky.
Statins- reduce blood cholesterol, this slowing down the levels at which fatty material is deposited in the coronary arteries m.
Why may valves leak?
The pressure over time can become too much
How can you fix a faulty valve?
Replace it with a mechanical valve or a biological valve
What is a disadvantage if a mechanical valve?
You would need to take medicine for the rest of your life to prevent clotting
What is a biological valve and what are the advantages and disadvantages?
A valve based on valves from animals like pigs
Advantage- no medicine needed
Disadvantage- only last 12-15 years
What happens if your heart beats too slow?
Not enough oxygen will get around the body
What happens if the heart beats too fast?
It cannot pump blood properly
How can you fix problems with the rhythm of the heart?
A pacemaker
What is a pacemaker and how do they work?
An electronic device that corrects irregularities of the hearts rhythm- two wires send signals to your heart to stimulate it to beat again.
Advantages and disadvantages of a pacemaker
Advantages- you are alive and will increase the quality and length of your life
Disadvantages- will need regular medical checkups
What is an artificial heart?
An electronic device that uses air pressure to pump blood around the body
Advantages and disadvantages of an artificial heart?
Advantages- improve your quality and length of life
A good short term method as heart transplants are not widely available
Disadvantages- potential risks of blood clotting
Very expensive
Why are heart transplants not common?
As people have to wait for a donor heart that is a tissue match
How does breathing in draw air to your lungs?
As ribs move up and out due to the diaphragm and intercostal muscles contract, the volume of the chest increases. Increased volume means lower pressure in the chest- atmospheric air is then at a higher pressure than the chest, so air is drawn into lungs.
Name the basic travel of oxygen to your blood cells?
Nasal cavity, throat, voice box, trachea (wind pipe), broncos, bronchiole, alveoli, blood cells
What is breathing?
Inhalation and exhalation
Why do humans need a gas exchange system?
To oxygenate our blood and remove waste carbon dioxide
What does the diaphragm do?
Strong sheet of muscle that expands your lungs when breathing in.
How does breathing out expel air from the lungs?
As the ribs fall due to the diaphragm and intercostal muscles relaxing, the volume of the chest gets smaller. This increases the pressure inside the chest due to decreased volume, thus air is forced out of the lungs.
By what process does oxygen move into your lungs, and carbon dioxide moves out?
Diffusion
What are some adaptations of the alveoli?
- Larger surface area- most effective diffusion.
- Rich supply of blood flow from capillaries- maintains concentration gradient for diffusion of oxygen into the body and carbon dioxide out of the body
- Thin layer of cells between lungs and the blood in capillaries- diffusion has shortest possible distance
How does ventilation result in quick gas exchange?
By constantly breathing- the concentration of oxygen in your lungs is always very high, and so diffusion down the concentration gradient (oxygen diffusing into the blood) happens extremely quickly. By constantly breathing, the concentration of carbon dioxide in the lungs is lower than the carbon dioxide in the blood, and so diffusion down the concentration gradient (carbon dioxide diffusing from the blood to the lungs) happens extremely quickly.
How is the trachea adapted to aid respiration?
Contains rings of cartilage that prevent it from collapsing
What are the organs in a plant?
Leaf, stem and roots
What is the leaves function?
Carries our photosynthesis
What is the function of the stem?
Supports the leaves and flowers
What is the function of the roots?
Take up water and minerals from the soil
What are the plants tissues?
Epidermal tissue, palisade mesophyll, sponges mesophyll, xylem, phloem, meristem tissue
What is the role of the epidermis?
To protect the surface of the leaf
How is the upper epidermis adapted?
Transparent- allows light to pass to the photosynthetic cells below
Has a waxy cuticle- prevents the evaporation of water from the leaf- this prevents the leaf from drying out
How does the lower epidermis help gas exchange?
Contains stomata- allow carbon dioxide to enter the leaf and oxygen to leave.
How is the palisade mesophyll adapted?
- Contains lots of palisade cells- contain chloroplasts for photosynthesis
- At the top of the leaf to get as much light as possible
How is the spongey mesophyll adapted?
- Contains lots of air space that allows carbon dioxide to diffuse from the stomata through to the palisade cells, and oxygen to diffuse from the palisade cells to the stomata
What is the role of the xylem tissue?
- To carry water for the plant from the stem to the leaves- some is then used in photosynthesis
- To transport dissolved mineral ions such as magnesium which is used to make chlorophyll
What is the role of the phloem tissue?
- Transports dissolved sugars produced by photosynthesis from the leaves to the rest of the plant- some is used immediately in respiration whilst others are stored such as starch
What is the scientific name describing the movement of sugars and other particles trough the phloem tissues?
Translocation
What is the role of meristem tissue?
Contains stem cells which can differentiate for the pants needs
Where do you find meristem cells?
Shoots and roots
Describe the structure of the cross section of a leaf?
- At the top there is a translucent upper epidermis.
- Beneath this there is palisade mesophyll, high on the leaves for optimum photosynthesis, and containing lots of palisade cells for photosynthesis
- Then there is a sponges mesophyll layer with lots of air space to ensure the diffusion of oxygen from the palisade cells to the stomata and carbon dioxide from the stomata to the palisade cells
- Below this is the lower epidermis, containing a stomata which aids gas exchange
What is the plants organ system?
The whole body of the plant (roots stem and leaves) form an organ system for the transport of substances around the plant
What are dissolved sugars in a plant needed for?
Needed for the growing of the plant to make new cells
Provides an energy store for the winter
What do aphids do?
Plant pests that push their sharp mouthparts into the phloem and eat the sugary fluid. Too many of these can lead to a plant dying due to having no food
Why are young trees susceptible to damage by animals?
The xylem makes up the bulk of wood, and the phloem is found in a ring just underneath. If a complete ring of bark is eaten, the transport systems stop and the tree will die
Why are mineral ions needed within a plant?
Production of proteins and other molecules within the cells
Why does a plant need water?
For photosynthesis (to provide glucose) To hold itself upright, as the vacuole presses the cytoplasm against the cell wall, it gives the cell structure and thus the plant support
What does cilia do in the lungs?
Pushes mucus from the lungs so you don’t drown due to liquid in the lungs
What do guard cells do?
Control the opening and closing of the stomata
What is transpiration?
Loss of water vapour from the leaves of a plant through the stomata when they are open for gas exchange
What is the transpiration system?
Water moves into the plant roots from the soil by osmosis. This water then moves up the plant, into the stem, and then into the leaves ( as it is replacing the water already lost by transpiration). This water then evaporates from the leaves of the plant (through the open stomata), and so more water is pulled up through the xylem to take its place. This constant movement of water molecules through the xylem from the roots to the leaves is known as the transpiration system.
Why is it important that plants can close their stomata?
To limit water vapour loss
What factors affect the rate of transpiration?
Temperature, humidity, the amount of air movement, and light intensity
How will an increase in light intensity affect transpiration?
The rate of transpiration will be quicker as the stomata is opening to let in carbon dioxide for photosynthesis
How will hot, dry or windy conditions affect transpiration?
They increase the rate of transpiration because more water evaporates from the leaf. Hot and dry air causes water vapour to evaporate quicker, whilst wind physically blows water off of the leaf.
How does temperature affect the rate of transpiration?
The molecules move faster, so diffusion occurs more rapidly. The rate of photosynthesis also increases, and so the stomata will open for more gas exchange to take place, resulting in water vapour loss from the leaves.
How do plants adapt to prevent water loss?
- Most leaves have a waxy cuticle to prevent uncontrollable water loss. In hot weather this cuticle can be very thick- as the stomata is on the underside of the leaf, this protects them from the direct sun light
- The plant will wilt in order to decrease surface area available for water loss by evaporation
- The stomata will close which risks overheating of the plant
What happens when plants begin to lose too much water?
The plant may wilt
