Biology, please help!

[rexsun]

Could anybody explain why the answer is A? I think the observations of all three are all positive....

And.

I think the answer should be C, yet it turns out to be D.
Extremely confused though... Although ER and mitochondria are all extremely small, couldn't them be visible by proper staining?

Any reply is appreciated, thanks, guys.

 

[Nibz]

MCQ 12.

Benedict's Test is positive, so: Reducing Sugar present.
Biuret Test positive, so: Protein present.
Iodine Test negative (positive test gives a dark blue colour), so: Starch not present.
The answer is clearly A. All three tests can't possibly be positive since there is no such answer in the options.

MCQ 22.
No, ER and Mitochondria in plant cells can only be seen under electron microscope.

 

[rexsun]

MCQ 12.

Benedict's Test is positive, so: Reducing Sugar present.
Biuret Test positive, so: Protein present.
Iodine Test negative (positive test gives a dark blue colour), so: Starch not present.
The answer is clearly A. All three tests can't possibly be positive since there is no such answer in the options.

MCQ 22.
No, ER and Mitochondria in plant cells can only be seen under electron microscope.

All right, it seems I misunderstood some material... Thanks very much.