Biology MCQ thread..!!

[Banglarbagh]

Guies post ur problematic bio MCQs here.!
Hope i can help u and inreturn u may help me.!

 

[Banglarbagh]

anyone answer dis please.

A sequence of amino acid may end in either an aminoo group (-NH2) or a carboxyl group (-COOH). wt is the theoritical number of chemically different dipeptides that may be assembled from 20 different amino acids.?

A. 40 B. 80 C. 400 D. 160

 

[RiseAgainst]

 

[Banglarbagh]

bro i gss the ans is A.!

 

[RiseAgainst]

Yeah it is. But why?

 

[imissknow2]

anyone answer dis please.

A sequence of amino acid may end in either an aminoo group (-NH2) or a carboxyl group (-COOH). wt is the theoritical number of chemically different dipeptides that may be assembled from 20 different amino acids.?

A. 40 B. 80 C. 400 D. 160

The answer to your question is C 400

dipeptide means that the chain is only made up of 2 amino acid.
using math permutation calculation the 1st amino acid can be one out of the 20 possible amino acid the second one can also be one of the 20 amino acid.
thus by multiplying 20 by 20 ie 20 x 20. you will get 400 possible combinations

thus 400 different Dipeptides

 

[imissknow2]

Yeah it is. But why?

if the person have a lowest resting heart beat per min, it means that his heart is able to pump the largest amount of blood (oxygenated and deoxygenated) circulating around the body per pump.

same goes to the heart beat per minute after sport, the lower the better cause this means that the heart is not as stressed compared to one who has a much higher heart beat.

Hope this helps good luck for Bio MCQ !

 

[lushpush]

Can anybdy please solve w10/q24

 

[RiseAgainst]

Can anybdy please solve w10/q24

Which variant?

 

[Banglarbagh]

sry man riseagainst i ws bit bzy.! and btw u got ur ans too..!!

and lushpush pls upload ur queston wch can benefit others too..!!!

 

[Banglarbagh]

anyone answer this pls.!

1.Wt effect would b causd by cutting the sympathetic nerve fibres to the heart ?

A. a decrease in heartbeat rate.
B. a decrease in length of diastole phase
C. a decrease in length of systole phase
D. a decrease in stroke volume.

 

[Banglarbagh]

2. Surgery on the septum in the lower region of the human heart may cause damage to the nerve fibers within the septum (bundle of His).

Wch phase of the cardiac cycle wuld b directly affected by such damage.?

A. atrial systole
B. atrio ventricular node stimulation
C. diastole
D. ventricular systole.

 

[Banglarbagh]

3. wch statement explains the significance myoglobin in muscle tissue.?

A. myoglobin can associate wth O2 in conditions of high CO2 tension
B. myoglobin can dissociate from oxygen most readily under aerobic conditions.
C. myoglobin acts as an O2 store delaying the onset on anaerobic respiration.
D. myoglobin acts as a buffer to hydrogen ions produced during anaerobic respiraton.

 

[Banglarbagh]

 

[Banglarbagh]

 

[Banglarbagh]

 

[RiseAgainst]

2. Surgery on the septum in the lower region of the human heart may cause damage to the nerve fibers within the septum (bundle of His).

Wch phase of the cardiac cycle wuld b directly affected by such damage.?

A. atrial systole
B. atrio ventricular node stimulation
C. diastole
D. ventricular systole.

It's D, right?
'cause the bundle of His conducts the excitation wave (from the AVN) causing the ventricles to contract (ventricular systole).

 

[RiseAgainst]

B.
Active transport occurs against a concentration gradient (from a low concentration to a high concentraion).
There's a higher concentration of K+ inside the cell than outside, so K+ is moved into the cell by active transport.
There's a higher concentration of Na+ outside the cell than inside, so Na+ is moved out of the cell by active transport.

This is what I think, anyway.

 

[mrpaudel]

the answer is B...its easy..!! the formation of 1-4 and 1-6 glycosidic bond..!!

 

[Banglarbagh]

thnx guies btw wt abut prblem 1 & 2..! :wink: