- Messages
- 167
- Reaction score
- 91
- Points
- 38
-
We need your support!
We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
A level Biology: Post your doubts here!
- Thread starter XPFMember
- Start date
- Messages
- 1,229
- Reaction score
- 740
- Points
- 123
no d
- Messages
- 1,229
- Reaction score
- 740
- Points
- 123
yes can u explain why not B
- Messages
- 139
- Reaction score
- 70
- Points
- 38
no, they need oxygen for working
- Messages
- 1,318
- Reaction score
- 1,374
- Points
- 173
that is very weird, I just double checked with CIE endorsed textbook 2013 third edition as well as the encyclopedia
nitrogen fixation in soil requires
supply of hydrogen, supply of ATP, anaerobic conditions
ONLY nitrogen fixation in the atmosphere which is caused by lightning which directly converts N2 to NO2/NO skipping NH3 requires aerobic condition.
- Messages
- 110
- Reaction score
- 136
- Points
- 53
hydrolytic enz. catalyse the hydrolyses of macromolecules to their constitute monomers by catalysing the breakage of bonds between the monomer units eg.amylase catalyse the hydrolysis of starch to maltose by breaking the glycosidic bondswhat are hydrolytic enzymes??
and yeah it is D
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
Only peptide bonds... Because this is simply a dipeptide... The space is too tight for two adjacent cysteine molecules to form disulfide bond.why can't this be B? disulphide nd peptide???
We need longer chains for such associations to occur.
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
93 seconds... Time is always to a whole number of seconds... Our hands are too inaccurate and our reaction times too slow for having decimal accuracy...
- Messages
- 167
- Reaction score
- 91
- Points
- 38
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
I've taken a guess at this before Here
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
- Messages
- 167
- Reaction score
- 91
- Points
- 38
The answer is 75...
- Messages
- 110
- Reaction score
- 136
- Points
- 53
hope this make things clear
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
A i think
Because yes water moves through membranes everywhere, as a result of random motion.
And yes water moves into cell 1 by osmosis, since it has a low (-7 is lowest number there) water potential.
As for number 3, it is wrong, water DOES move in both directions, just that both rates are same and so overall there is no net movement, but water still moves in both directions.
As for number 4, water does move out but this doesn't necessarily always mean that plasmolysis has occured.
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
- Messages
- 110
- Reaction score
- 136
- Points
- 53
well nitrogen fixing bacteria in root nodules need anaerobic conditions but this is achieved as the legumes mop up the oxygen in the soil this means they can grow in aerated soils but in anaerobic conditions however the nitrifying bacteria needs aerobic conditions and denitrifying bacteria can only grow in anaerobic conditions which needs to be maintained since they are found free in the soil
- Messages
- 110
- Reaction score
- 136
- Points
- 53
well thanksWow amazing.
Good to see effort being put into answers
people here helped me a lot this year and the year before so i thought i should be of some use!
- Messages
- 1,229
- Reaction score
- 740
- Points
- 123
but what if it was stopwatch? :s
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
- Messages
- 924
- Reaction score
- 1,096
- Points
- 153
Yeah of course stopwatch...
But we cannot have so many significant figures..
Because our finger pressing stop button is not very precise...
54.85 seconds seems to imply you're certain to this many decimal places, but everytime you take a reading it won't be exactly the same.