For the 3 marker Why did the CO2 levels in the flask increase I wrote:
Microorganisms break down the grass taking in the carbon. When they respire they release CO2 which is trapped due to the cotton wool blocking its escape, causing it to build up in the flask.
For the second part I wrote that all the grass had been decomposed.
Just because the grass has been decomposed doesn't mean the microbes aren't respiring, the second part I think was that the microbes had died because either the they had run out of food(grass) or oxygen
The cotton wool allows gases to flow in and out, by your logic if it prevented gases leaving then oxygen would't be able to enter too. But the marks I think are as follows: 1) Decomposers such as bacteria and fungi will decompose the rotting matter. 2)They then use the nutrients, such as glucose in AEROBIC respiration 3) By product of this is CO2 which is released
The cotton wool allows gases to flow in and out, by your logic if it prevented gases leaving then oxygen would't be able to enter too. But the marks I think are as follows: 1) Decomposers such as bacteria and fungi will decompose the rotting matter. 2)They then use the nutrients, such as glucose in AEROBIC respiration 3) By product of this is CO2 which is released
The cotton wool doesn't gases to flow in and out otherwise the graph wouldn't have shown an increase in CO2, it would have stayed constant the CO2 would have moved out due to diffusion
The cotton wool doesn't gases to flow in and out otherwise the graph wouldn't have shown an increase in CO2, it would have stayed constant the CO2 would have moved out due to diffusion
It allows the gases to seep through, so oxygen can enter. However, some co2 would be lost, since cotton can't cover the entire gap. And secondly, I think you can imply the micro-organisms die as a result of lack of food as its 20 days after, but the main point is that all of the grass had decayed.
For the 3 marker Why did the CO2 levels in the flask increase I wrote:
Microorganisms break down the grass taking in the carbon. When they respire they release CO2 which is trapped due to the cotton wool blocking its escape, causing it to build up in the flask.
For the second part I wrote that all the grass had been decomposed.
theres literally no point in trying to find out whether or not you got a question right or not. The exam is OVER. move on with your life!
The cotton wool allows gases to flow in and out, by your logic if it prevented gases leaving then oxygen would't be able to enter too. But the marks I think are as follows: 1) Decomposers such as bacteria and fungi will decompose the rotting matter. 2)They then use the nutrients, such as glucose in AEROBIC respiration 3) By product of this is CO2 which is released
You don't have to put aerobic because it's not in core
You don't have to put aerobic because it's not in core
Last year the answer to one of the questions was enzymes denatured and ribosomes - these are very easy ideas and are most prominent in B2 yet still turned up.
the microbes had died due to a lack of oxygen in the flask because they had released so much co2 there was not any oxygen left for respiration
The most obvious answer is that decomposition had finished, but you may have got it wrong, because there;s always oxygen in the flask, since the cotton allows gases to move in and out.