B4 - Organising Animals and Plants Flashcards
What is the aorta?
the artery that leaves the heart from the left ventricle and carries oxygenated blood to the body
What are arteries?
blood vessels that carry blood away from the heart. They usually carry oxygenated blood and have a pulse
What is an atrium?
the upper chambers of the heart
What are capillaries?
the smallest blood vessels. They run between individual cells and have a wall that is only one cell thick
What are coronary arteries?
the blood vessels that supply oxygenated blood to the heart muscle
What is the double circulatory system?
the circulation of blood from the heart to the lungs is separate from the circulation of blood from the heart to the rest of the body
What is the epidermal?
the name given to cells that make up the epidermis or outer layer of an organism
What are guard cells?
surround the stomata in the leaves of plants and control their opening and closing
What is Haemoglobin?
the red pigment that carries oxygen around the body in the red blood cells
What is the palisade mesophyll?
the upper layer of the mesophyll tissue in plant leaves made up of closely packed cells that contain many chloroplasts for photosynthesis (this layer performs the most photosynthesis)
What is phloem?
the living transport tissue in plants that carries dissolved food (sugars) around the plant
What is plasma?
the clear yellow-liquid part of the blood that carries dissolved substances and blood cells around the body
What are platelets?
fragments of cells in the blood that play a vital role in the clotting mechanism of the blood
What is the pulmonary artery?
the large blood vessel that takes deoxygenated blood from the right ventricle of the heart to the lungs
What is the pulmonary vein?
the large blood vessel that carries oxygenated blood from the lungs back to the left atrium of the heart
What are red blood cells?
biconcave cells that contain the red pigment haemoglobin and carry oxygen around the body in the blood
What is the spongy mesophyll?
the lower layer of mesophyll tissue in plant leaves that contains some chloroplasts and many large air spaces to give a big surface area for the exchange of gases
What are statins?
drugs used to lower blood cholesterol levels and improve the balance of high- to low-density lipoproteins in the blood
What is a stent?
a metal mesh placed in a blocked or partially blocked artery. They are used to open up the blood vessel by the inflation of a tiny balloon
What is translocation?
the movement of sugars from the leaves to the rest of the plant through the phloem
What is transpiration?
the loss of water vapour from the leaves of plants through the stomata when they are opened to allow gas exchange for photosynthesis. It involves evaporation from the surface of the cells and diffusion through the stomata
What is urea?
the waste product formed by the breakdown of excess amino acids in the liver
What are veins?
blood vessels that carry blood back to the heart. They usually carry deoxygenated blood and have valves to prevent the backflow of blood
What is the vena cava?
the large vein that brings deoxygenated blood from the body into the heart
What are ventricles?
chambers of the heart that contract to force blood out of the heart
What are white blood cells?
blood cells involved in the immune system of the body. They engulf pathogens and make antibodies and antitoxins.
What is xylem?
the non-living transport tissue in plants that transports water from the roots to the leaves and shoots
What is blood made of?
Red Blood Cells, White Blood Cells, Platelets and Plasma
What do red blood cells do?
There are more red blood cells in your body than any other cell. They pick up oxygen from your lungs and carry it to cells
How are red blood cells adapted?
They have a biconcave shape, giving them a larger surface area and SA:V ratio for diffusion. They are packed with haemoglobin which binds to oxygen. They have no nucleus to make room for haemoglobin. The shape makes it faster for diffusion of oxygen through the membrane
How are white blood cells adapted and what do they do?
White blood cells are much bigger than red blood cells and there are fewer of them. They have a nucleus and form part of the bodies defence system. Lymphocytes (a type of white blood cell) form antibodies against pathogens. Some types form antitoxins against poisons from bacteria, and others engulf and digest bacteria and viruses
How are platelets adapted and what do they do?
Platelets are small fragments of cells. They have no nucleus. They are very important in helping the blood clot at the site of a wound.
What is blood clotting?
Blood clotting is a series of enzyme controlled reactions to form a scab
What is plasma?
Plasma is a yellow liquid
What does plasma do?
It transports your red blood cells, white blood cells and platelets around your body. It carries the waste CO2 back to your lungs , urea formed in your liver is carried to your kidneys where it is removed to form urine and small soluble products of digestion pass into the plasma and transports to individual cells
The circulatory is system is a _______ ________ system
Closed double
What does a closed double system mean?
It means that blood always stays within the blood vessels and that blood flows through the heart twice on each complete circuit of the body.
What is pulmonary circulation?
The circulation that brings deoxygenated blood to your lungs from your heart and then oxygenated blood from your lungs to your heart
What is systematic circulation?
The circulation that brings oxygenated blood from your heart to the cells all around your body and then deoxygenated back from the body to your heart
What is the structure of an artery?
They have a thick wall and then a thick layer of muscle and elastic fibres. They have a small lumen
What does an artery do?
Arteries carry blood away from your heart. This blood is bright-red oxygenated blood. Arteries have thick walls containing muscle and elastic fibres. This is because blood in arteries is under high pressure. It can be very dangerous if an artery is cut. Arteries stretch as blood goes through them and go back into shape afterwards
What is the structure of a vein?
They have relatively thin walls and have a large lumen. They also have valves to prevent the backflow of blood
What does a vein do?
Veins carry blood away from the organs towards your heart. This blood is deoxygenated and is dark red in colour. Veins do not have a pulse. They have thinner walls than arteries and have valves to prevent backflow of blood. Blood is squeezed towards the heart by the action of skeletal muscles
What is the structure of a cappilary?
Capillaries have 1 cells thick walls and are a tiny vessel with a narrow lumen
What does a cappilary do?
Capillaries form a huge network of tiny vessels linking arteries and veins. Their walls are 1 cell thick. This allows substances such as oxygen and glucose to diffuse quickly into your cells. This also allows waste substances such as CO2 to diffuse into your blood
What are coronary veins/arteries?
Coronary arteries supply oxygenated blood to your heart wall muscle and coronary veins take away the deoxygenated blood from the heart wall muscle
Which side of the heart has thicker walls and why?
The left side of the heart has thicker walls (especially the left ventricle). This is because it has to pump the blood all around the entire body. This requires strong muscles to make sure that the blood makes it all the way around the body.
What is the vena cava?
The deoxygenated blood enters the right atrium through the vena cava
What is the aorta?
The oxygenated blood exits the left ventricle to be pumped all around the boy through the aorta
What is the pulmonary artery?
The deoxygenated blood exits to right ventricle to go to the lungs through the pulmonary artery
What is the pulmonary vein?
The oxygenated blood enters the left atrium from the lungs through the pulmonary vein
What is an atrium?
Blood enters the top chambers of your heart these are called “atria”. The atria contract together and force blood down into the ventricles.
What is a ventricle?
The ventricles are the lower chambers of your heart. They contract and force blood out of the heart
What are atrioventricular valves?
Atrioventricular valves close to stop the backflow of blood in the heart
What are leaky valves?
Over a lifetime, heart valves have to withstand a lot of pressure. This may cause them to leak or become stiff and not fully open. This makes the heart less efficient
How are leaky valves treated?
Doctors can operate and replace them with mechanical heart valves. They could be made of substances such as titanium or polymers. They are long lasting, however blood clots can form around them so patients have to take medicine for the rest of their lives. Doctors can also replace leaky valves with biological valves such as valves taken from pigs or cows. These do not form blood clots. However, they only last 12-15 years
When are artificial pacemakers needed?
The heart has a natural pacemaker called the SA node (it is found in the right atrium). It generates an electrical stimulus which makes the heart chamber contract/relax. the resting rhythm of a healthy heart is 70bpm. If the SA node stops working properly it can cause serious problems. If the heart beats too slowly it cannot pump blood properly. An artificial pacemaker can be inserted to correct the irregularities in the heart rate. They weigh between 20g and 50g. You will need regular check-ups throughout your life
When is an artificial heart needed?
If a heart fails completely an artificial pacemaker cannot save them, in this case they would need a heart transplant. If you have a heart transplant you need to take constant medication to prevent your body rejecting your new heart. If there is not a new heart available they may need a temporary artificial heart. However, artificial hearts can have a risk of blood clot which can lead to death
What is a stent and when is it used?
In coronary heart disease the arteries that supply blood to the heart become narrow. A common cause of this is a build up of fatty material on the inner lining of the vessels. This restricts blood flow and therefore and therefore oxygen supply. This can cause pain, a heart attack and even death. A stent is a metal mesh that is placed in an artery. A tiny balloon is inflated to open up the blood vessel and the stent at the same time. The balloon is deflated and removed, but the stent stays and holds the blood vessel open.
What are statins and when are they used?
Statins are prescribed to anyone who is at increased risk of cardiovascular disease. They reduce blood cholesterol levels and this slows down the rate at which fatty material is deposited in coronary arteries
What % of air breathed in is nitrogen?
~80%
What % of air breathed out is nitrogen?
~80%
What % of air breathed in is Oxygen?
~20%
What % of air breathed out is Oxygen?
~16%
What % of air breathed in is Carbon Dioxide?
0.04%
What % of air breathed out is Carbon Dioxide?
~4%
What are the adaptations of Alveoli?
There are many alveoli and they have a spherical shape, these provide a very large surface area for the diffusion of Oxygen and carbon dioxide. Alveoli have a very thin wall and this allows for rapid diffusion of Oxygen and carbon dioxide. Alveoli have many capillaries surrounding them, this maintains a steep concentration gradient, making gas exchange rapid and effective
Describe how air moves in and out of your lungs
Ventilating the lungs is brought about by the contraction and relaxation of the intercostal muscles between the ribs and the diaphragm, changing the pressure inside the chest cavity so air is forced in or out of the lungs as a result of differences in pressure. When you breath in the oxygen-rich air moves through your mouth/nose then down your trachea (windpipe). It then moves in to your bronchi before splitting into your bronchioles. Finally it moves into your alveoli (air sacs) where it diffuses into the blood
What are the plant organs
Flowers, Leaves, Stem, Roots
What is the role of a flower?
Flowers allow plants to reproduce
What is the role of a Leaf?
Leaves carry out photosynthesis
What is the role of a Stem?
Stem supports leaves and flowers, and transports water and nutrients
What is the role of a Root?
Roots take up water and minerals from the soil and keep the plant stable in the soil
What is the structure of a leaf?
A leaf has an upper epidermis followed by mesophyll tissue which contains palisade mesophyll and spongy mesophyll. The mesophyll tissue is then followed by the lower epidermis. In the lower epidermis there are gaps called stomata. There are xylem and phloem transport systems adjacent to the mesophyll tissue.
What is the structure of a Stem?
A stem has xylem and phloem arranged in vascular bundles
What is the structure of a root?
A root has xylem arranged in an x shape and 4 phloem around the xylem
What does the upper epidermis do?
The upper epidermis covers the surfaces and protects them. These cells often often secrete a waxy substance that waterproofs the surface of the leaf
What does the palisade mesophyll do?
The palisade mesophyll tissue contains lots of chloroplasts, which carry out photosynthesis
What does the spongy mesophyll do?
Spongy mesophyll tissue contains some chloroplasts for photosynthesis but also has big air spaces and a large surface area to make diffusion of gases easier
What does the lower epidermis do?
The lower epidermis covers the surfaces and protects them. These cells often often secrete a waxy substance that waterproofs the surface of the leaf. They also contain gaps called stomata
What does xylem do?
Xylem transports water and dissolved mineral ions from the roots up to the leaves and it supports the plant
What does phloem do?
Phloem transports dissolved food from the leaves to other cells in the plant
What is meristem tissue?
Meristem tissue is at the growing tips of roots and shoots and is made of rapidly dividing plant cells that grow and differentiate into all the other cell types needed
Why do flowering plants need a transport system?
They are multicellular and often large, this means that they have a small SA:V ratio. They have to transport glucose made by photosynthesis and water from the soil to all cells in the plant
What is xylem?
the non-living transport tissue in plants that transports water from the roots to the leaves and shoots
What is phloem?
the living transport tissue in plants that carries dissolved food (sugars) around the plant, this is called translocation
What is Transpiration?
Transpiration is the evaporation of water from the leaves. the water vapour passes out of the open stomata from the lower epidermis
How does water enter the roots?
Osmosis
What do stomata do?
Stomata can be opened when the plant needs to allow air into the leaves. Carbon dioxide from the atmosphere diffuses into the air spaces and then into the cells down a concentration gradient.
How is the opening and closing of the stomata controlled?
Guard cells swell with water and cause the stomata to open. To close the stomata, the guard cells lose water and return to a limp state
How does temperature effect Transpiration rates?
As temperature increases, the rate of transpiration increases. This is because as temperature increases, the molecules gain more kinetic energy and begin to move faster, and the water evaporates this causes diffusion to occur more rapidly. Also, as temperature increases the rate of photosynthesis increases, so more stomata will open for gas exchange to take place.
How does humidity effect Transpiration rates?
As humidity increases, the rate of transpiration decreases. This is because the diffusion of the water vapour out of the leaf is slower. This is due to the leaf already being surrounded by moist air, this makes it harder for the water vapour to diffuse out the leaf
How does Wind Speed effect Transpiration rates?
As the air movement increases, the rate of transpiration increases. This is because the moving air removes the water vapour, increasing the rate of diffusion of water vapour from the leaf
How do plants control water loss?
Plants have a waxy cuticle that to prevent uncontrolled water loss. The stomata are also on the bottom of the leaf so that they are not facing direct sunlight. If the plant begins to lose water faster than it is replaced by the roots, it can result in some drastic measures:
- The whole plant may wilt. Wilting is a protection mechanism against further water loss. The leaves all collapse and hang down. This greatly reduces the surface area available for water loss by evaporation.
- Stomata close, this stops photosynthesis and risks overheating . However, this prevents most water loss and any further wilting
What does a potometer measure?
the uptake of water
Why does a potometer not measure the transpiration rate of a plant?
A potometer measures the uptake of water, not the transpiration rate. This is because although most water taken up by a plant is lost in transpiration, a small amount is used in the plants metabolism
