Biology: Transportation Flashcards
Function of Xylem`
Transports water taken from the root hair cells to the rest of the plant
Function of Phloem
Transports substances made by the plant[assimilates] from sources to places where they are stored
Identify the positions of xylem tissues as seen in transverse sections of unthickened, herbaceous, dicotyledonous roots, stems and leaves.
Xylem is on the top of a leaf and the innermost part of the stem and root.
Phloem is on the bottom of the leaf and the outermost part of the stem and root.
Identify root hair cells, as seen under the light microscope, and state their functions.
They take up water and minerals from the soil
Relate the structure and functions of root hairs to their surface area and to water and ion uptake.
Large surface area. Vacuole has high salt concentration therefore allowing water to perform osmosis quicker.
Define transpiration as evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata.
Evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata.
Describe the effects of variation of temperature, humidity and light intensity on transpiration rate.
Increase of temperature increases transpiration rate as the concentration gradient becomes wider. More kinetic energy in the particles so they can move out of the leaf quicker.
Increase of humidity decreases transpiration rate as the concentration gradient becomes smaller
Increase of light intensity increases transpiration rate as plants begin to photosynthesise quicker which leaves the stomata open.
Describe the circulatory system as a system of tubes with a pump and valves to ensure one-way flow of blood.
System of tubes with a pump and valves to ensure one-way flow of blood.
Describe the double circulation in terms of a low-pressure circulation to the lungs and a high-pressure circulation to the body tissues, and relate these differences to the different functions of the two circuits.
The right hand side of the heart only pumps blood to the lungs therefore have a low-pressure circulation.
The left hand side of the heart pumps blood all around the body and hence need a high-pressure circulation to send it all around the body.
Describe the structure of the heart, including the muscular wall and septum, atria, ventricles, valves and associated blood vessels
Deoxy blood arrives through the vena cava on the right hand side. (Inferior from body, Superior from head). It enters the right atria and is sent through the tricuspid valve into the right ventricle. From here, it is sent to the lungs to re-oxygenate through the pulmonary valve and then the pulmonary artery.
From the lungs, it travels to the heart through the pulmonary vein. From the left atria, it then enters through the mitral (bicuspid) valve to the left ventricle where it then leaves the heart to the head and body through the aortic valve and then through the aorta.
There are tendons that support the valves.
Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible causes (diet, stress and smoking) and preventive measures.
Coronary Heart Disease is caused by factors such as smoking, stress and a fatty diet.
Plaque(cholesterol) builds up and can stick to the sides of the coronary arteries which can then reduce the level of oxygen flowing to the heart. Sometimes, blood clots may form. Heart failure/heart attacks could soon follow CHD.
To prevent CHD, don’t smoke, have a balanced diet and do plenty of exercise.
Describe the function of the heart in terms of muscular contraction and the working of the valves.
The left and right atria contract at the same time with the two valves opening to flow into the two ventricles. The valves then close and the left and right ventricles push blood through the last two valves to move around the body.
Investigate the effect of physical activity on pulse rate.
Physical activity increases pulse rate as your muscles need more oxygen to replace the oxygen that has been used up while exercising.
Identify red and white blood cells as seen under the light microscope on prepared slides, and in diagrams and
photomicrographs.
Red blood cells are biconcave and have no nuclei to optimise the storage of oxygen.
White blood cells are large with weird broken things in the middle?
Describe and explain the structure and functions of arteries, veins and capillaries
Arteries have thick walls and thick layers of muscle and elastic fibres which allows blood to be pumped at high pressure. They pump blood away from the heart and to the different organs. They are more elastic because it’s high pressure.
Veins have thinner walls and thinner layers of muscle and elastic fibres as the blood is being pumped at a lower pressure. They pump blood towards the heart. They are less elastic because it’s low pressure.
Capillaries are branches of an artery. They are one cell thick, very narrow and they reach body cells. Oxygen and glucose can easily diffuse from the capillaries to the cells and carbon dioxide and other waste easily diffuse into the capillaries as well. Arteries split into capillaries which then join together with veins.
