绿色植物
互联网
1091
Word | Definition | Topic |
---|---|---|
capillarity | the tendency of water to move up a narrow tube - the effect of water molecules clinging to each other and clinging to the sides of the tube | Green plants as organisms |
chlorophyll | the green chemical inside the chloroplasts of plant cells. It enables photosynthesis to take place. | Green plants as organisms |
evaporation | the process in which a liquid turns into a gas | Green plants as organisms |
flaccid | lacking turgor; lacking in stiffness or strength | Green plants as organisms |
guard cells | specialised cells which control the opening and closing of stomata in a green plant's leaves | Green plants as organisms |
impermeable | not allowing water to pass through | Green plants as organisms |
light energy | energy in the form of light (from the sun). It is needed for photosynthesis, which changes light energy into chemical energy. | Green plants as organisms |
lignin | a hard cellulose-like substance which gives rigidity to plant tissues | Green plants as organisms |
limiting factor | Something which prevents or slows down a process. Temperature, carbon dioxide concentration and light intensity can all be limiting factors on photosynthesis. | Green plants as organisms |
mesophyll | the inner tissue of a leaf, whose cells are green because they contain chloroplasts | Green plants as organisms |
mesophyll cells | the inner tissue of a leaf, whose cells are green because they contain chloroplasts | Green plants as organisms |
palisade mesophyll | the upper layer of mesophyll where photosynthesis mostly takes place | Green plants as organisms |
permeable | allowing water to pass through | Green plants as organisms |
phloem vessels | vein-like structures through which food is transported round a plant | Green plants as organisms |
respire | to engage in respiration - the energy-producing process inside living cells | Green plants as organisms |
root hair cells | tiny hairs covering the ends of the smallest roots. They give the root a very large surface area through which to absorb water and mineral salts from the soil. | Green plants as organisms |
spongy mesophyll | the lower layer of mesophyll which contains numerous air spaces where gas exchange takes place | Green plants as organisms |
starch | a type of carbohydrate. Plants can turn the glucose produced in photosynthesis into starch for storage, and turn it back into glucose when it is needed for respiration. | Green plants as organisms |
stomata | tiny holes in the epidermis (skin) of a leaf - usually on the undersides of leaves. They control water loss and gas exchange by openng and closing. Singular is stoma | Green plants as organisms |
sucrose | a complex sugar. Sugar cane and sugar beet store sucrose instead of starch - and we use it to sweeten food | Green plants as organisms |
suction pressure | pressure caused by loss of water through a plant's leaves, which draws or sucks replacement water up the plant from the roots | Green plants as organisms |
transpiration | the loss of water from leaves by evaporation. It is much faster when stomata are open than when they are closed | Green plants as organisms |
transpiration stream | the constant cycling of water from the soil, into the plant through its roots, up the plant by suction pressure and capillarity to the leaves, where it is lost by evaporation to the atmosphere, or used up in photosynthesis. | Green plants as organisms |
tropism | growth or movement towards or away from a stimulus such as light, gravity or moisture | Green plants as organisms |
turgid | having turgor; enlarged and swollen with water | Green plants as organisms |
variegated | with alternating green and white patches. In variegated leaves, photosynthesis only occurs in the green patches, as the white patches contain no chloroplasts. | Green plants as organisms |
vascular bundle | vein-like structure in the roots, stems and leaves of plants, consisting of xylem and phloem tubes | Green plants as organisms |
xylem vessels | vein-like tissues which transport water and minerals up a plant | Green plants as organisms |