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Bio P1 DOUBT.

S

sami

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Hey everyone, i need an explanation for the answer to Q24,25 and Q33 in NOV 2005 paper .\\

Thankx in advance.
 
L

lost

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Ans to oct/nov 2005 Q24 ..on sample three when uracil is 25 ,C is nil...which shows that C is thymine. (and since adenine pairs up with thymine and uracil..).so to be adenine it should be that column where all the values coincide or is very near(+-1) to values under C..which we can find under B.
Qn.25= B, and D cannot be the option since water passes to adjacent celss through interconnecting plasmodesmata not the cell wall. and both A and c seems to be corect..in apopplast water enters vacuole but not necessary that it will have to enter there and come out to make apoplast way but in cytoplasm it jas to so a is the answer...its confusing..:p
Qn.33..
vital capacity=full inspiration -full expiration..
Qn.7.o/n 03 its D.
As water potemtial=pressure potential+sloute potential.
since water po. and solute po are equal they cancel out each other ..makin Pressure potential 0...al da best guys..
 
E

elixa

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I am really confused abt the concepts of tidal volume and vital capacity.......Can enyone explain in detail pleaz. For instance i cnt do OCT NOV 2004 P1 Q32...I KNW WHICH ANS IS CORRECT BUT CAN SUM1 EXPLAIN Y THE OTHERS R INCORRECT...................
 
A

ammadb

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@elixa
a is incorrect as breathng normal hai fr the frst 30 seconds by the graph.
c is incorrect cx by counting squares we find that volume isnt 1000cm3
d is incorrect cox there r only 8 complete waves in 30 seconds..
 
A

Ather Hussain

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T

the_giver

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Nov 2004
25. Analysis of DNA produced the following ratios of nitrogenous bases.

bean seeds 0.99
cow heart 1.01
human liver 1.02
rat bone marrow 1.00

Which statement explains the difference in the ratios?
A Animal DNA contains more purines than pyrimidines.
B Different parts of organisms contain different proportions of purines and pyrimidines.
C DNA contains thymine instead of uracil.
D There are variations in the accuracy of analytical techniques.

Ans: D
Explanation: Choices C ans A are not supported. B is too extreme..........D is the best answer

June 04
16 Which process is the movement of molecules that are too large to diffuse in through a cell surface
membrane?
A active transport
B endocytosis
C facilitated diffusion
D osmosis

Ans: B
Explanation: Only endocytosis involves the transport of large molecules like proteins.

June 03
6 Many fresh water animals possess vacuoles which contract regularly, expelling excess water.
Why do plants living in fresh water not require such vacuoles?
A Plant cell sap has a much lower concentration of dissolved solutes than animal cytoplasm.
B Plant cell walls are impermeable to water.
C The water potential is the same inside and outside the plant cells.
D Water movement into plants is controlled by their roots.

Ans:C
Explanation: The water potential inside and outside the cells are the same due to an increase in pressure potential inside plant cells - the effect of cell walls

Nov2002
32 Four people of the same age, sex and mass had their pulse rate taken before and immediately
after taking a standard strenuous exercise.
Which person had the most well developed heart muscle?

pulse rate / beats per minute
person resting after exercise
A 55 160
B 72 190
C 75 180
D 81 175
Ans: A - lowest pulse rate b4 and after exercise

June 2002
I couldn't get the ques paper...............no link
 
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