Biology; Chemistry; Physics: Post your doubts here!

[kirann]

ook now these investigations are mind pasturing...pplz explain
1) how can we investigate amout of o2 from inspired air different from expired air ?
2)how can we investigate amout of CO2 from inspired air different from expired air ?
3) is heat produced during respiration?
4)is CO2 given off during fermentation (anaerobic respiration)?

 

[ciesgetoveralready]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w13_qp_62.pdf
Ques 1 part cii. Would'nt it be accuracy ? Sorry but Im confused which I should'nt be.

Why dont you just write " to calculate the average" that would be less confusing. Because honestly things like these confuse me too. So i just go for other words instead

 

[Awesome12]

Can someone give me the answers to this?

 

[kirann]

Can someone give me the answers to this?

View attachment 41236

whats the result b/w A n B... will try to answer according to the question

 

[peacce]

ook now these investigations are mind pasturing...pplz explain
1) how can we investigate amout of o2 from inspired air different from expired air ?
2)how can we investigate amout of CO2 from inspired air different from expired air ?
3) is heat produced during respiration?
4)is CO2 given off during fermentation (anaerobic respiration)?

i know 4 limewater thing

 

[Mahnoorfatima]

Can someone give me the answers to this?

View attachment 41236

If you could post the question...

 

[ciesgetoveralready]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w13_qp_62.pdf
Ques 1 part cii. Would'nt it be accuracy ? Sorry but Im confused which I should'nt be.

Btw, the number of bubbles cannot be accurate. They will be different everytime. Like see the measurement of a chair will always be the same so that is accurate. But the number of bubbles wont be the same everytime so you do the test more than once for reliability because you cant get the accurate answer. Like I hope you understand what Im trying to say

 

[kirann]

i know 4 limewater thing

i want somebody to explain these to me

 

[Mahnoorfatima]

Btw, the number of bubbles cannot be accurate. They will be different everytime. Like see the measurement of a chair will always be the same so that is accurate. But the number of bubbles wont be the same everytime so you do the test more than once for reliability because you cant get the accurate answer. Like I hope you understand what Im trying to say

LOL. Yep I get you! (a bit though) but thanks. I'll probably use the other way! Using easier words would fetch me more marks.

 

[Awesome12]

If you could post the question...

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s03_qp_6.pdf
Question 2

 

[ciesgetoveralready]

LOL. Yep I get you! (a bit though) but thanks. I'll probably use the other way! Using easier words would fetch me more marks.

Lol yeah exactly! I always go for the less complicated things. Too much complication is out of my league *_*

 

[Dark Destination]

Are there any topics that i can skip for Bio atp? Ecology, maybe? It seems useless. .-.

 

[kirann]

at what pH amylase works best acidic or alkaline?

 

[Fate0]

Can someone give me the answers to this?

View attachment 41236

1) Prepare a control experiment with boiled saliva.
2) Keep the amount of water same in both experiments.
3) The temperature of both experiments should be same.

 

[Dark Destination]

at what pH amylase works best acidic or alkaline?

Salivary amylase works in neutral.

 

[Fate0]

at what pH amylase works best acidic or alkaline?

Depends on which amylase you look at.
The amylase in mouth works at a pH of 7 as saliva is neutral.
The pancreatic amylase is alkalin-ic as it works in the alkaline pancreatic juice.

 

[kirann]

Depends on which amylase you look at.
The amylase in mouth works at a pH of 7 as saliva is neutral.
The pancreatic amylase is alkalin-ic as it works in the alkaline pancreatic juice.

actually i was going through an investigation in which they have provided
acidic, slightly acidic, neutral, slightly alkaline and alkaline pH to test which works best, they did not mention if the amylase is salivary or pancreatic, so i am confused which results would be positive

 

[ciesgetoveralready]

actually i was going through an investigation in which they have provided
acidic, slightly acidic, neutral, slightly alkaline and alkaline pH to test which works best, they did not mention if the amylase is salivary or pancreatic, so i am confused which results would be positive

can you post the link of the investigation?

 

[kirann]

can you post the link of the investigation?

its in my book and results are not written

 

[Mahnoorfatima]

Can someone give me the answers to this?u

View attachment 41236

Keeping the temperature constant.
The amount of water in test tubes be the same
Don't know about the third one but I once read this question in pure where they said that a control should be set up but I don't get why? :/