• 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!

J

Jinosupreme

Messages
94
Reaction score
29
Points
28
Jaspreet Dhaliwal said:
ano anyone? :D
Click to expand...

1) it's MICROSCOPE, only can reach till micro μm, hence is 3 and 4
4) use formula (pie)r^2. See properly, there is 100 small divisions along the circle. Since 0.1mm(1 division of bigger scale) covers 40 smaller divisions, use ration method to calculate. 100/40 = (diameter)/0.1mm. Then u get 0.25mm. Then u need radius hence 0.25/2 = 0.125mm. change it to m. Hence (pie)(0.125 X 10^-3)^2 = ur answer. Change unit

15) not A because partially denatured is wrong, should be denatured or not, don't have partial. Other is quite obvious

19) the key of is HAPLOID - Capable of reproduction. Hence since its haploid, should be ASEXUAL REPRODUCTION since it cannot go through reduction division
 
Z

ZulfahSA

Messages
10
Reaction score
13
Points
13
Jinosupreme said:
http://olevel.sourceforge.net/papers/9700/9700_s13_qp_12.pdf

need HELP IN Q3,4, 16, 40
3C
4A
16D
40A
Click to expand...


Jinosupreme said:
http://olevel.sourceforge.net/papers/9700/9700_s13_qp_12.pdf

need HELP IN Q3,4, 16, 40
3C
4A
16D
40A
Click to expand...


For Question 4A
Note that the question is asking for the features that enable you to IDENTIFY that it is a prokaryote.
It is true that prokaryotes have cell wall, nucleus, ribosomes and DNA. However, eukaryotes also have those features. The only difference that tells you that it is a eukaryote or prokaryote is the DNA. Prokaryotes have a circular DNA and eukaryotes have linear molecules (chromosomes).

# The question is just trying to confuse you :)

Question 16D
For factors that increses the fluidity of the membrane are:
1) Unsatured phospolipid tail - Fatty acid tails are bent
2) Increse in temperature
3) Cholestrol

For 1 single bonds between carbon atoms in fatty acid chains means that it is saturated. Thus it decreases the fluidity of the membrane
2 Longer chains of fatty acid does not affect any fluidity of the membrane

Question 3 and 40 somewhat still confuses me

Correct me when I'm wrong! Thank you very much! :D
 
S

Snowysangel

Messages
872
Reaction score
894
Points
103
Kinki Tiffany 12 said:
What's the role of ribosome? It's a 4 mark question. Anyone?
Click to expand...
They're used in protein synthesis. MRNA is made in the nucleus and this contains instructions for protein synthesis. It goes to the ribosomes where amino acids are rearranged to build the specific kind of protein
 
A

Aparajita

Messages
1
Reaction score
0
Points
1
Hey,
I am appearing for Oct/Nov A level Biology examination,I am in serious need of help.Can anybody provide me with the notes of meiosis genetics and gene control ,biotechnology and crop plant notes. Plase.:)
 
mimi1077

mimi1077

Messages
15
Reaction score
3
Points
13
hello everyone, i just wanted to know if there is practical in a-level biology because our school does not offer a-level biology so i am planning to do it outside the school and if i did the as level how many papers are left to complete the full a-level?
thxxxxx for your time :)
 
queen of the legend

queen of the legend

Messages
169
Reaction score
117
Points
38
mimi1077 said:
hello everyone, i just wanted to know if there is practical in a-level biology because our school does not offer a-level biology so i am planning to do it outside the school and if i did the as level how many papers are left to complete the full a-level?
thxxxxx for your time :)
Click to expand...

yes ofcourse there is practical that is paper 3 in AS level
its very important for you to do your as from a good school provided they have good lab, experienced teachers. A2 anyhow you can work on with good tuition only
if you get to have a good base initially ull do well ..
 
Busy Buddy

Busy Buddy

Messages
228
Reaction score
1,685
Points
153
question_3a) explain briefly how the stimulus at the finger produces an impulse in the sensory neuron? May/June 2005_paper 4

This is what the mark scheme says & I don't get it : :(

idea of energy conversion ( linked to receptor) ;
Na+ in / AW ;
depolarization ;
receptor / generator potential ;
ref. to threshold ;
(therefore) action potential / wave of depolarisation ;

How do you even write this in sentences? :confused:
 
Atiqa asl

Atiqa asl

Messages
244
Reaction score
144
Points
53
mimi1077 said:
hello everyone, i just wanted to know if there is practical in a-level biology because our school does not offer a-level biology so i am planning to do it outside the school and if i did the as level how many papers are left to complete the full a-level?
thxxxxx for your time :)
Click to expand...
in as 3 paper are there which r ppr 1 2 3 and in a2 u have 2 paper 4 5 among them u have more weight age for paper 2 and 4
r u planning to give bio privately
 
You must log in or register to reply here.
Top