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Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 356810 times)

Offline the_grim_reaper

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3180 on: June 07, 2010, 07:29:48 pm »
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?

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...
« Last Edit: June 07, 2010, 07:32:59 pm by deadman786 »
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3181 on: June 07, 2010, 07:30:30 pm »
Quote from: Ivo on June 07, 2010, 07:16:47 pm
Please can someone explain these doubts.

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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Offline Ivo

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3182 on: June 07, 2010, 07:32:20 pm »
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.

LOL, I thought the fruits were carrots and potatoes!
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Offline the_grim_reaper

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3183 on: June 07, 2010, 07:34:47 pm »
Quote from: Ivo on June 07, 2010, 07:32:20 pm
LOL, I thought the fruits were carrots and potatoes!

Fruit is anything formed by fertilization that produces seeds in the ovary in flowering plants. That also makes tomato fruits !!:D.
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Offline SNA

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3184 on: June 07, 2010, 07:35:09 pm »
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)
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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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3185 on: June 07, 2010, 07:35:14 pm »
Quote from: ambitious94 on June 07, 2010, 07:26:59 pm
Heyy can anyone please help me out with June 09 Q 3)
How cum it's not B and it's D...doesnt the plant have just four stamen ..UGHHH... ???
I cant manage more than 37 :(



^^Monocot leaf- parallel veins




^^Dicot Leaf- fibered/branched veins
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Offline Ivo

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3186 on: June 07, 2010, 07:35:35 pm »
Another doubt, please help.  I think it's been answered before, but why is the silver thing stopping it?  it's only thin layer, so surely auxins are still exposed on shoot tip.

I mean metal, not silver!  ;P
« Last Edit: June 07, 2010, 07:40:52 pm by Ivo »
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3187 on: June 07, 2010, 07:41:55 pm »
Quote from: Ivo on June 07, 2010, 07:35:35 pm
Another doubt, please help.  I think it's been answered before, but why is the silver thing stopping it?  it's only thin layer, so surely auxins are still exposed on shoot tip.

I mean metal, not silver!  ;P

Don't really break your head because its not it the syllabus! ;)
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Offline Shazizzzle

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3188 on: June 07, 2010, 07:43:00 pm »
Quote from: ~VIN1094~ on June 07, 2010, 07:41:55 pm
Don't really break your head because its not it the syllabus! ;)

*phew* I couldn't answer it. :P
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Offline the_grim_reaper

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3189 on: June 07, 2010, 07:47:07 pm »
Quote from: Ivo on June 07, 2010, 07:35:35 pm
Another doubt, please help.  I think it's been answered before, but why is the silver thing stopping it?  it's only thin layer, so surely auxins are still exposed on shoot tip.

I mean metal, not silver!  ;P


First thing that I can't really get is that have they managed to cut the shoot into two and then placed agar and metal or have they made a hole and passed a shoot through it lol :D.

If they've cut it, they I think the one with agar jelly and the untouched shoot should show tropism. How??? I don't feel right choosing metal lol :D...
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3190 on: June 07, 2010, 07:50:48 pm »
Quote from: deadman786 on June 07, 2010, 07:47:07 pm

First thing that I can't really get is that have they managed to cut the shoot into two and then placed agar and metal or have they made a hole and passed a shoot through it lol :D.

If they've cut it, they I think the one with agar jelly and the untouched shoot should show tropism. How??? I don't feel right choosing metal lol :D...

LOL ... This is what I can't understand too. Anyway, apparently the explanation is :: The sugar agar allows the auxin to pass through as it is organic and the metal doesn't.
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Offline the_grim_reaper

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3191 on: June 07, 2010, 07:51:41 pm »
Guys just one thing, in the circulatory system what is an artery??? I mean an organ, tissue etc. And is blood actually a tissue here??? (LOL my understanding of tissues is limited to colony of cells :D)...
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Offline the_grim_reaper

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3192 on: June 07, 2010, 07:52:24 pm »
Quote from: ~VIN1094~ on June 07, 2010, 07:50:48 pm
LOL ... This is what I can't understand too. Anyway, apparently the explanation is :: The sugar agar allows the auxin to pass through as it is organic and the metal doesn't.

Most probably!!
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Offline Shazizzzle

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3193 on: June 07, 2010, 07:53:46 pm »
Umm, M/J 2000, P1,  Q 27.
How is the answer D?
Shouldn't it be C, because the foliage leaves have begun to develop, and as soon as they do, photosynthesis starts, thus increasing the mass.
Though there is also a possibility that the production and usage is at equilibrium, because they plant is still growing, so the is making use of the resources?
But, point is, the increase should start as leaves have formed, and that is C.
???
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #3194 on: June 07, 2010, 07:55:34 pm »
Quote from: deadman786 on June 07, 2010, 07:51:41 pm
Guys just one thing, in the circulatory system what is an artery??? I mean an organ, tissue etc. And is blood actually a tissue here??? (LOL my understanding of tissues is limited to colony of cells :D)...

Arteries and veins are BLOOD VESSELS

Blood cannot be a tissue, though it may have RBCs or WBCs, collection if cells as you say.. they don't really "join up" to do specific tasks. Let's just say the blood is a mixture of cells, ions etc. etc.
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