Qualification > Sciences
CHEM AND BIO HELP AND TIPS HERE
the_grim_reaper:
--- Quote from: Ivo on June 07, 2010, 07:21:03 pm ---Please can someone explain. I thought photosynthesis (plant nutrition) absorbs carbon dioxide and gives off oxygen. Why respiration?
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I think you're confusing it. Look it says which process leads DIRECTLY to the exchange of gases indicated. During the night, plants don't make oxygen from photosynthesis so they have to absorb it. And since they aren't photosynthesising, they release it carbon dioxide directly. During the part of the day with bright sunlight, the oxygen is still produced but its actually a lot more than necessary and released. Carbon dioxide is also made but its a lot less. So the plant has to absorb it from the surroundings...
Secondly, in that question about seeds, its wind for seed 2 cause look at it. They have a large surface area to increase air resistance..
and the other is mammal for attaching to it (I've never seen birds with seeds on em :D.)
Thirdly, that question about the leaf, alcohol (common reference to ethanol) is B. Just recall the process of testing a leaf for starch. First, its boiled to make it permeable, then heated with ethanol (using a water bath since ethanol is flammable) to dissolve chlorophyll then washed with water then iodine is added...
Vin:
--- Quote from: Ivo on June 07, 2010, 07:16:47 pm ---Please can someone explain these doubts.
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1. D, Respiration uses O2 and gives off CO2
2. B, Spiked fruit 1 sticks to mammal fur, fruit 2 feathered and has large surface area so modified to be dispersed by wind
3.B, alcohols are always heated in a water bath to avoid combustion when in direct touch with flame.
Ivo:
--- Quote from: ~VIN1094~ on June 07, 2010, 07:30:30 pm ---1. D, Respiration uses O2 and gives off CO2
2. B, Spiked fruit 1 sticks to mammal fur, fruit 2 feathered and has large surface area so modified to be dispersed by wind
3.B, alcohols are always heated in a water bath to avoid combustion when in direct touch with flame.
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LOL, I thought the fruits were carrots and potatoes!
the_grim_reaper:
--- Quote from: Ivo on June 07, 2010, 07:32:20 pm ---LOL, I thought the fruits were carrots and potatoes!
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Fruit is anything formed by fertilization that produces seeds in the ovary in flowering plants. That also makes tomato fruits !!:D.
SNA:
--- Quote from: aangel42 on June 07, 2010, 07:24:58 pm ---Correction: plants always respire!!!
It involves the same equation as for humans (aerobic respiration = oxygen in, CO2 out)
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during daylight, plants photosynthesis as well as respire, so that all co2 produced by respiration is used up by photosynthesis. at the same time, all oxygen needed by respiration is provided by photosynthesis. when in dark, plants do not photosynthesis. thus the rate of respiration is faster than photosynthesis,thus releasing co2 gas.
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