AS Biology P1 MCQs Preparation Thread

Jaf

Jaf

Messages
321
Reaction score
232
Points
53
Hey I checked. You're right. It's wrong on the uploaded paper. Scandalous! :sneaky:
 
aliya_zad

aliya_zad

Messages
144
Reaction score
21
Points
28
Nibz said:
Net Primary Productivity is the rate of production of organic food after allowing for that lost via respiration by plant.
So rate at which energy is lost via respiration = 5000 kJm^-2year^-1
Total = 1000,000
5000/1000 000 x 100
= 0.5 %
Click to expand...

Thank u!
 
egy

egy

Messages
292
Reaction score
66
Points
38
Mubarka said:
Q4) One division of stage graticule is of 0.1mm. This covers about 50 divisions of the eyepiece graticule. this means that this can be calibrated as 0.002mm per division. ( by the unitary method, i.e.
mm : divisions on eyepiece gr.
0.1 : 50
x : 1
so, x = 0.1mm/ 50 = 0.002mm)
After four hours, the pollen tubes grow, select the one horizontal i.e. parallel to the scale. This covers approx. 10 divisions, which means that this is
10 x 0.002 = 0.02mm grown in 4 hours.
using again the unitary method,
0.02 : 4
y : 1
y = 0.02/4 = 0.005 mm per hour.
Convert this into μm, answer comes A which is 5μm/h
Click to expand...


Thank U :):):);) a TON
 
shaadhir

shaadhir

Messages
9
Reaction score
1
Points
3
Why does a photosynthetic prokaryote have no chloroplasts
check out M/J 2011 p-12 question no-4
 
L

logophile

Messages
13
Reaction score
8
Points
13
I need help with Nov2010. Paper11. Q39.
I can't figure out why producers give primary consumers lesser energy (10%) than they give to secondary consumers(20%)
 
HuN3yy !!

HuN3yy !!

Messages
24
Reaction score
2
Points
3
18 Male bees are haploid. They develop from unfertilised eggs. Female bees are diploid.
Which statements are correct?
1 All male bees are genetically identical.
2 Male bee sperm cells are produced by mitosis.
3 New combinations of genes only occur in female bees.


A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

guyss em reposting this qst ..plz do help :( :|
 
K

knightrider1994

Messages
8
Reaction score
1
Points
13
Which agricultural practice will not provide an alternative to the use of ammonium nitrate as a
fertiliser to increase the productivity of wheat?
A growing wheat and another cereal crop in the same field in alternate years
B growing wheat and beans in the same field in alternate years
C ploughing animal waste such as dung into the soil
D using synthetic urea as a fertilizer

Answer is A not B. Can someone explain the reason for that ? Confused :S
 
S

Soulgamer

Messages
462
Reaction score
166
Points
53
knightrider1994 said:
Which agricultural practice will not provide an alternative to the use of ammonium nitrate as a
fertiliser to increase the productivity of wheat?
A growing wheat and another cereal crop in the same field in alternate years
B growing wheat and beans in the same field in alternate years
C ploughing animal waste such as dung into the soil
D using synthetic urea as a fertilizer

Answer is A not B. Can someone explain the reason for that ? Confused :S
Click to expand...

They are talking about which will not provide an alternative use of ammonium nitrate. In B beans i.e leguminous plants will fix nitrogen thus providing nitrate's. In C, Animal dung contains nitrate. In D they are using fertilizers so the option A is the one where nitrates are not being provided.
 
S

sagar65265

Messages
227
Reaction score
571
Points
103
Soldier313 said:
can someone please urgently help me with
qn paper: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_11.pdf
ms: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_11.pdf
qn 10 - why B and not D?
qn 11 - explanation pleaaaasee
qn 18 - why not A?
qn 25 - why not A?
qn 29 - why C and not A??

thanx so much and God bless!!!
Click to expand...

Q10: Amino acids have the -COOH group, which gives them acidic properties but they do not HAVE to have 2 or more -OH groups, because 2 of the 4 possible groups on the simplest possible amino acid which has 1 central carbon atom are already used used for an -NH2 group and a -COOH group. One is always reserved for hydrogen, so an amino acid doesn't have to have 2 or more hydroxyl groups, so the first option should be included.
Glycerol is a triol, meaning that it has 3 alcohol/hydroxyl groups already, so while it doesn;t have any -COOH groups, it has to have 3 hydroxyl groups too, so the third option is wrong, giving B.

Q11: It'll take a while to explain this buddy, and I'll do it after some time, because I have to go for something else now, but i'll surely get back to you!

Q18: In the process of cell division, the process of Telophase occurs before cytokinesis:

In this order: Prophase ==> Metaphase ==> Anaphase ==> Telophase ==> Cytokinesis

The reforming of the nuclear membrane occurs in telophase, thus number 3 is invalid. Also, the cell organelles themselves do not divide during this phase - the organelles divide during the cell cycle G1 and G2 phase while S phase is devoted to genetic material division:

http://wiki.answers.com/Q/During_wh...es_duplicate_and_centrosome_replication_begin

This leaves out only the centre option which is true indeed.

Q25: Hair around the leaves traps a static of air if i'm not mistaken, keeping the air around the leaf humid and making the concentration of water in the inner environment similar to the concentration of water in the outer environment, i.e. reducing the gradient of water for diffusion. The gradient is simply the concentration difference.
Sunken stomata also does the same as above but by keeping the stomata away from air currents - the air around the stomata which is humid does not get blown away and the gradient is kept abour constant to prevent excessive water loss.
When leaves roll up, this places the stomata in an enclosed space not exposed to the wind. The groove formed by the rolled leaf also acts as a channel for rain water to drain directly to the specific root of the grass stem. This maintains a very low gradient for diffusion.
Fewer stomata decrease water loss but don't affect the difference between the internal and external water concentrations, i.e. the gradient.
As far as I know, the 5th one doesn't do anything, but it's just a guess. This should help:
http://quizlet.com/2305002/topic-92-continued-flash-cards/

Q29: Tissue Fluid contains NO plasma proteins so the concentration of proteins in tisssue fluid should be less than in Plasma, and about platelets, I don't know but this should help:
http://en.wikipedia.org/wiki/Interstitial_fluid#Composition

Hope this helps!
 
I

Ineedhelp

Messages
35
Reaction score
12
Points
18
xxfarhaxx said:
Q 15- ans B..bt y?? shudnt it be C??
Q 30
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s06_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s06_ms_1.pdf
Click to expand...
for Q 15 the answer is B because they are talking about Active Transport, in which energy is required.
so molecules move from a lower concentration to a higher concentration, AGAINST the concentration gradient (using up energy) .. like climbing up a steep hill. =p
 
xxfarhaxx

xxfarhaxx

Messages
249
Reaction score
90
Points
38
Ineedhelp said:
for Q 15 the answer is B because they are talking about Active Transport, in which energy is required.
so molecules move from a lower concentration to a higher concentration, AGAINST the concentration gradient (using up energy) .. like climbing up a steep hill. =p
Click to expand...
tnx.. i gues didnt read da quatn proply!!! wat abt Q 30??
 
You must log in or register to reply here.
Top