A level Biology: Post your doubts here!

[Lola_sweet]

View attachment 53214
Why is it B
I know it's passive but the body is infected by a snake bite so shouldn't it be natural ?

toxin was injected into the horse which means the antibodies produced r artificial
antibodies arent produced by one's self when they r injected with the antiserum

 

[Lola_sweet]

D ... but i don't know why :S

higher the magnification lower the resolution

think of it like when u zoom into a picture
picture starts to get blurry the more u zoom in
and thts wht resolution is the distinguishing between 2 points

 

[Lola_sweet]

How do we solve this? PLEASE HELP ASAP!

Correct answer is A.

wht paper is this?

 

[nehaoscar]

wht paper is this?

summer 14 variant 12

 

[Lola_sweet]

summer 14 variant 12

i thought productivity isnt in the syllabus

 

[ashcull14]

if e is the no of 34 amino acids and DNA only contained 2 types of nitrogenous bases ..what would be the minimum no. of bases per codon that could code for proteins?

 

[nehaoscar]

wht paper is this?

i thought productivity isnt in the syllabus

Sorry thats not the papaer i quoted some one else's doubt but yeah productivity is (like not in v. detail but there is some info in the book)

 

[nehaoscar]

if e is the no of 34 amino acids and DNA only contained 2 types of nitrogenous bases ..what would be the minimum no. of bases per codon that could code for proteins?

Isn't it always 3 - the triplet code?

 

[Lola_sweet]

Sorry thats not the papaer i quoted some one else's doubt but yeah productivity is (like not in v. detail but there is some info in the book)

explain how energy losses occur along food chains and discuss the efficiency of energy transfer between trophic levels;
^this is all the syllabus says

 

[nehaoscar]

explain how energy losses occur along food chains and discuss the efficiency of energy transfer between trophic levels;
^this is all the syllabus says

Ohh... but the text book has about gross primary productivity etc...

 

[Lola_sweet]

Ohh... but the text book has about gross primary productivity etc...

Yep ik but qwertypoiu told me it isnt
unless i am mixing things up

 

[Heba A.Moety]

plz if any one has notes about serial and simple dilution in paper 5 can u pass it on !

 

[ShanMMQ]

ariyupki

 

[My Name]

plz if any one has notes about serial and simple dilution in paper 5 can u pass it on !

Take a look at this https://www.xtremepapers.com/community/threads/as-biology-33-2015-m-j.41027/#post-913998
you might find it here

 

[ashcull14]

Isn't it always 3 - the triplet code?

oh ryt thnks

 

[ashcull14]

anyone having nov 2000 markscheme p1?

 

[nehaoscar]

Answer's B
but doesn't it also only occur in A and D?
what else occurs in A and D then? :S

 

[nehaoscar]

I thought cholera is food borne too :/
but its D

 

[Laila39]

PLEASEEEE someone explain this method to me Im not able to do any of these questions please help my exam's tomorrow and also does someone have any notes or tips for A2 P5?

 

[ashcull14]

View attachment 53216
Answer's B
but doesn't it also only occur in A and D?
what else occurs in A and D then? :S

hes talking about ONLY mitosis...if u remember cancer is a result of uncontrolled mitosis ONLY
well its confusing but a combination of 2 nd 3 are more likely bcz the chances of bacterial transmission increases with greater no of people nd lack of washing facilities whereas for the 1st one ...bact transmission can be prevented widout refregeration like proper packing so and so.....