Biology MCQ thread..!!

[sweetiepie]

have anyone has done specimen papers....

 

[zxc1230]

Can somebody please help me with question 34 on this paper? (may june 06)
http://www.xtremepapers.me/CIE/Internat ... 6_qp_1.pdf
Apparently the answer is D.. i understand that viruses don't have ribosomes and they don't respire, but what i don't get is the cell surface membrane part.. cause mycobacterium tuberculosis is a prokaryote so it has a cell membrane and Plasmodium falc. is a protoctist which is a eukaryote and also has a membrane.. in my textbook it also says the HIV virus has a lipid membrane soo why is there a cross in that box? :/

Also another quick question on that paper.. In question 6 we're supposed to measure that gap in the middle from the start to the end to get the width right? Just making sure cause my answer was different since my paper wasn't the same size

 

[sweetiepie]

look in question 6. C is answer
i measure one phospolipid 1.8 cm ---->8nm

magnification = 1.8x10^7/8 = 2.5x10^6 so answer is C

I HOPE UR CLEAR....

 

[aliya_zad]

Answer to shooting star's question...

Ans is A.

initially during metaphase the sister chromatids are held together by the centromere. The distance btw shud therefore be almost 0 initially, which increases in the later stages of metaphase when the centromere splits and moves towards the polesHence itz 2.
Initially the centromeres and poles of spindle are a distance apart which gradually decreases once they come closer to each other.hence itz 1.
Distance btw poles of spindle will remain almost constant throughout, therefore itz 3.

 

[ShootingStar]

Answer to shooting star's question...

Ans is A.

initially during metaphase the sister chromatids are held together by the centromere. The distance btw shud therefore be almost 0 initially, which increases in the later stages of metaphase when the centromere splits and moves towards the polesHence itz 2.
Initially the centromeres and poles of spindle are a distance apart which gradually decreases once they come closer to each other.hence itz 1.
Distance btw poles of spindle will remain almost constant throughout, therefore itz 3.

Alright, I get it. Thanks. I have another one..

 

[zxc1230]

@sweetiepie- why did you measure one phospholipid when it says the whole lipid bilayer has a length of 8 nm?

 

[Banglarbagh]

In most ecosystems, the greatest amount of energy flows through which trophic level?

A. Secondary consumers
B. Herbivores
C. Decomposers
D. Carnivores

June 99

Suldn't the answer b opton B..!!

 

[zxc1230]

Oh never mind i get it now.. i thought the width would be from left to right.. Thank you! If you could answer my other question id really appreciate it!

 

[sweetiepie]

UR WELCUM IN A LINE OF 2 PHOSPOLIPIDS GIVEN MESURE FRM SCALE U WIL GET 1.8CM SURELY N OTHER QUESTION DINT GET IT...

 

[ShootingStar]

10 views..no answer :roll:

 

[sweetiepie]

hmmm my question m/j 2006 Q.36???

 

[kirashinagami]

Hi, a question here :

The answer is B, if you get the same answer, pleas explain it to MEEE

 

[melon159]

 

[kirashinagami]

hmmm my question m/j 2006 Q.36???

It should be B.
because
P-antigen is present in the cell surface membrane of cells.
Q-T helper is the cells which detect the presence of foreign substance and secrete cytokines to stimulate B lymphocytes to produce antibodies
R-B lymphocyte recognize the pathogen by binding with the antigen of the pathogen and starts to produce the antibodies suited to the antigen of the pathogen

 

[sweetiepie]

thanks....

 

[kirashinagami]

1 division of stage micrometer = 40 divisions of eye piece
0.1 mm = 40 divisions of eyepiece
100 micrometer = 40 divisions of eyepiece
2.5 micrometer = 1 division of eyepiece
10 micrometer = 4 division of eyepiece

so the answer is B

 

[kirashinagami]

Answer to shooting star's question...

Ans is A.

initially during metaphase the sister chromatids are held together by the centromere. The distance btw shud therefore be almost 0 initially, which increases in the later stages of metaphase when the centromere splits and moves towards the polesHence itz 2.
Initially the centromeres and poles of spindle are a distance apart which gradually decreases once they come closer to each other.hence itz 1.
Distance btw poles of spindle will remain almost constant throughout, therefore itz 3.

Alright, I get it. Thanks. I have another one..

to shooting star

the answer is D
because - first convert the anticodon into codon
A. codon = GUA
B. codon = GAA
C. codon = ACU
D. codon = ACG

now you see the question. option A B and C are present in the formation of tRNA molecule of the sickle cell hb,
so the answer is D

 

[kirashinagami]

oh,and anyone can explain me my question?

 

[RiseAgainst]

Hi, a question here :

The answer is B, if you get the same answer, pleas explain it to MEEE

I think this has already been explained somewhere, but I'll answer it.
If you look at row 3, there's uracil in it - which means that column C must be thymine (as there's none of it).
Now that you know which one's thymine you just gotta look for another column that has a similar percentage to thymine ('cause A and T pair up).
The column that has percentages that are very similar to the thymine column is column B, so the answer is B.

I explained it kinda weirdly but that's the best way I could put it.
Hope you understood it!

 

[ShootingStar]

Answer to shooting star's question...

Ans is A.

initially during metaphase the sister chromatids are held together by the centromere. The distance btw shud therefore be almost 0 initially, which increases in the later stages of metaphase when the centromere splits and moves towards the polesHence itz 2.
Initially the centromeres and poles of spindle are a distance apart which gradually decreases once they come closer to each other.hence itz 1.
Distance btw poles of spindle will remain almost constant throughout, therefore itz 3.

Alright, I get it. Thanks. I have another one..

to shooting star

the answer is D
because - first convert the anticodon into codon
A. codon = GUA
B. codon = GAA
C. codon = ACU
D. codon = ACG

now you see the question. option A B and C are present in the formation of tRNA molecule of the sickle cell hb,
so the answer is D

I see!! Thanks