BIOL4 Biology Unit 4 Exam - 13th June 2011

Reply 520

*Rainbow*

Does anyone get question 2c in Jan 2011? The hardy weinberg? Dont really get why they got 48% I got like 27% :s-smilie:

Reply 521

Rickesh

Original post by *Rainbow*

Does anyone get question 2c in Jan 2011? The hardy weinberg? Dont really get why they got 48% I got like 27% :s-smilie:

You might not have needed to square root the p/q ? or you might need to? If you get me? I havent got the question in front of me

Reply 522

tehsponge

11

Original post by Rickesh

Nitrogen fixation is when the nitrogen in the atmosphere is converted into, firstly nitrite ions by an oxidatio reaction, then into nitrate ions again through oxidation. The nitrifying bacteria do this reaction, in aerobic conditions. Or some bacteria live in the roots of plants in nodules, they give the plant nitrate ions, for growth and the plant must give the bacteria carbohydrates in a mutualisitc relationship.
Is that right?

Nay, in nitrogen fixation the nitrogen fixing bacteria convert gaseous atmospheric nitrogen into ammonia, by a reduction reaction.

Reply 523

SK-mar

1

question:

What are nitrates used for in plants?

I can think of a couple of ideas: production of proteins. production on nucleic acids??? do they produce nucleic acids from nitrates? what else...

Reply 524

Stratos

15

Original post by Rickesh

Nitrogen fixation is when the nitrogen in the atmosphere is converted into, firstly nitrite ions by an oxidatio reaction, then into nitrate ions again through oxidation. The nitrifying bacteria do this reaction, in aerobic conditions. Or some bacteria live in the roots of plants in nodules, they give the plant nitrate ions, for growth and the plant must give the bacteria carbohydrates in a mutualisitc relationship.
Is that right?

It's ammonia first, nitrifying bacteria convert ammonia into Nitrite they also convert it to nitrate which is taken up be the roots of plants(active transport).

Original post by SK-mar

question:

What are nitrates used for in plants?

I can think of a couple of ideas: production of proteins. production on nucleic acids??? do they produce nucleic acids from nitrates? what else...

yes they form nucleic acids(organic bases always contain nitrogen which is why they're also called nitrogenous bases)

(edited 12 years ago)

Reply 525

*Rainbow*

Question: What is the role of ATP in the light dependent reaction?

Reply 526

Master.K

18

Isn't there a 5 marker on eutrophication in the nelson thrones book (examination style questions pg 102 q2b)?

Reply 527

*Rainbow*

Original post by Rickesh

You might not have needed to square root the p/q ? or you might need to? If you get me? I havent got the question in front of me

Thanks lol I got the answer right after i typed the question! D'oh

Reply 528

INeedToRevise

8

Original post by Rickesh

Nitrogen fixation is when the nitrogen in the atmosphere is converted into, firstly nitrite ions by an oxidatio reaction, then into nitrate ions again through oxidation. The nitrifying bacteria do this reaction, in aerobic conditions. Or some bacteria live in the roots of plants in nodules, they give the plant nitrate ions, for growth and the plant must give the bacteria carbohydrates in a mutualisitc relationship.
Is that right?

I think you have confused nitrogen fixation with nitrification.

Nitrogen fixation is where there are two types of bactera
1) Mutalistic think interaction. both get something from each other= live in nodules of plants and plant acquire amino acids from bacteria and the bacteria acquires carbohydrates.
2) Free living= convert gaseous nitrogen into ammonia which is used to make amino acids

Reply 529

User12399

5

Original post by *Rainbow*

Question: What is the role of ATP in the light dependent reaction?

its produced in the light dependent stage. (do you mean in light independent stage?)

Reply 530

tehsponge

11

Original post by SK-mar

question:

What are nitrates used for in plants?

I can think of a couple of ideas: production of proteins. production on nucleic acids??? do they produce nucleic acids from nitrates? what else...

Nitrogen is an element in DNA/amino acids, so the plant needs to get nitrogen from somewhere. Nitrates are water soluble and so can be easily taken up by the root hair cells of the plant. The nitrogen from the nitrates is used to make the DNA bases, and for the formation of amino acids. I think :colondollar:

Reply 531

SK-mar

1

Original post by Stratos

yes they form nucleic acids(organic bases always contain nitrogen which is why they're also called nitrogenous bases)

ok cheers man.

Reply 532

bbeckii

I also find timing so hard in this exam (to whoever said that before), takes so long to analyse the questions! I got an E in january, i'm hoping for at least a C tomorrow! Quickk question though, in respiration, how many molecules of ATP can you make from one glucose molecule? In the CGP textbook it says 32, i've got in my notes that it's 38, and then on some website's it's 36 :/

Reply 533

Master.K

18

Original post by bbeckii

I also find timing so hard in this exam (to whoever said that before), takes so long to analyse the questions! I got an E in january, i'm hoping for at least a C tomorrow! Quickk question though, in respiration, how many molecules of ATP can you make from one glucose molecule? In the CGP textbook it says 32, i've got in my notes that it's 38, and then on some website's it's 36 :/

I'd say 32 just because the CGP says it. :p:

Reply 534

User12399

5

Original post by bbeckii

I also find timing so hard in this exam (to whoever said that before), takes so long to analyse the questions! I got an E in january, i'm hoping for at least a C tomorrow! Quickk question though, in respiration, how many molecules of ATP can you make from one glucose molecule? In the CGP textbook it says 32, i've got in my notes that it's 38, and then on some website's it's 36 :/