IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: PurpleKnife on June 05, 2009, 08:07:48 am
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In Ecology, I don't understand the food chain which demonstrates energy flow.
Please explain.
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Grass-->Goat--->Fox
in the following food chain energy is transferred from the grass to the goat and then from the goat to the fox.
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In Ecology, I don't understand the food chain which demonstrates energy flow.
Please explain.
ANDDD as each organism is eaten, it looses 90% of the energy. So each trophic level, wil have less and less energy, hence the biomass getting smaller, as it goes up
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if sewage leaks into the lake
can someone tell me wot happens?
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if sewage leaks into the lake
can someone tell me wot happens?
oxygen level will decreease.
plants will die.
so will fish.
disease. ***
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if sewage leaks into the lake
can someone tell me wot happens?
oxygen level will decreease.
plants will die.
so will fish.
disease. ***
but algae increase right?
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sewage as a source of nitrate (nitrogen compounds) it will be considered as fertilisers which will be used by aquatic plants as algae to grow with high rate...they will grow to a great extent where they will block light from reaching the aquatic plants on the river bed or underwater....they will eventually die, so the aerobic bacteria will on them and so they will consume oxygen in the water......decreasing its concentration so the aquatic plants or animals will die due to suffocation or migrate. This is call EUTROPHICATION.
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algae increases i think..
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yes they DO!
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if sewage leaks into the lake
can someone tell me wot happens?
oxygen level will decreease.
plants will die.
so will fish.
disease. ***
but algae increase right?
Algae increase, and they rot, on the sea bed. therefore the bacteria use up all the oxygen therefore the fish dont have enough oxygen and die, this is called eutrophication
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please help:O/N 2007, paper 1, Question No.29
And can u please tell me the reason the answer is not B, because I think since there is light, the plant should bend, as auxin will be destroyed....
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Whos been -repping me.
What did i do??!
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Whos been -repping me.
What did i do??!
hello little girl... r u ready?
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Whos been -repping me.
What did i do??!
someones been doing the same thing 2 me
its very annoying
anywayz thank u all
now i got it
+rep
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Whos been -repping me.
What did i do??!
hello little girl... r u ready?
im sorry but that just sounded wrong :P
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Whos been -repping me.
What did i do??!
hello little girl... r u ready?
im sorry but that just sounded wrong :P
AHAHAHA QUESTION 27 JUNE 2005 explanation please anyone??
someone has been repping me too :(
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+ rep for u :)
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+ rep for u :)
thank you :) could you explain q. 27 june 2005
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+ rep for u :)
thank you :) could you explain q. 27 june 2005
the answer is D BECAUSE plant bends toward the light that is positive phottropism
and the invertebrates is in dark place which is negative phototaxis
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can someonle tell me
if u increase humidity and temperature etc
will the rate of transpiration increase?
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Increasing humidity=decrease transpiration
increasing temperature (not to much)=increases transpiration
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Someone, please answer my question....
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Increasing humidity=decrease transpiration
increasing temperature (not to much)=increases transpiration
thx
+rep
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+ rep for u :)
thank you :) could you explain q. 27 june 2005
It is D. This is because when Invertabrated move away from a light source, this is negative phototaxis.
When a plant bends towards the light, this is positive phototropism.
Also, remember that when invertabrates respond to chemicals, this is called Chemotaxis
When they respond to gravity, this is geotaxis
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bani
its B cuz leaves are green due to photosynthesis
its short cuz its too cold to grow
enzymes are not at their optimum
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please help:O/N 2007, paper 1, Question No.29
And can u please tell me the reason the answer is not B, because I think since there is light, the plant should bend, as auxin will be destroyed....
It has nothing to do with auxins..5 degree celsius is a low temperature..so enzymes are inactive..rate of photosynthesis is low so the plant will grow but not that high!
the answer is B By the way!
Hope u understood my explanation
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+ rep for u :)
thank you :) could you explain q. 27 june 2005
It is D. This is because when Invertabrated move away from a light source, this is negative phototaxis.
When a plant bends towards the light, this is positive phototropism.
Also, remember that when invertabrates respond to chemicals, this is called Chemotaxis
When they respond to gravity, this is geotaxis
thnkss
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please help:O/N 2007, paper 1, Question No.29
And can u please tell me the reason the answer is not B, because I think since there is light, the plant should bend, as auxin will be destroyed....
It has nothing to do with auxins..5 degree celsius is a low temperature..so enzymes are inactive..rate of photosynthesis is low so the plant will grow but not that high!
the answer is B By the way!
Hope u understood my explanation
Oh I meant why is the asnwer not D....So its because it says the colour of the leaf is yellow, but in B its green.
So, since photosynthesis is happening in B, the colour is green, and thats why the asnwer is B
Ok, thanks, +rep :)
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bani
its B cuz leaves are green due to photosynthesis
its short cuz its too cold to grow
enzymes are not at their optimum
Oh thanks, + rep :)
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And can please someone explain me Q31 , O/N 2007, pleaseee. How do we work it out?
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@bani
well a 1:1 ratio is the same as 50%
so which of them produced 50of each characteristic
so ans is C
gettit?
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@bani
well a 1:1 ratio is the same as 50%
so which of them produced 50of each characteristic
so ans is C
gettit?
Oh yaaa, thankssss so much I'll +rep again after 2hrs :D
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haha
thx
glad that u understand