E
A is not true ; Does not satisfy condition 2.
B is not true ; Does not satisfy condition 1.
C is not true ; Does not satisfy condition 1 & 2.
D is not true ; Does not satisfy condition 2.
As per the conditions and P on Thursday & N on Friday, 
E
As per the conditions in the above statement A, B, C, D cannot appear on the schedule. Only E adheres to the conditions. If L is on Monday, P could be on Tuesday.
C
The option C is the only relevant and appropriate answer. Apart from C all the other options do not satisfy the given conditions in the premises.
C
Because imitation of coral snake affords the less poisonous species a measure of protection it would not otherwise have. Rest of the alternatives are irrelevant.
E
Other alternatives are inapplicable while A & D are ridiculous.
C
Because the biologist used the information that type X grows only in medium 3.
M1 U V W
M2 T Y Z
M3 T W X Z
A
Because type V & W can be differentiated as only W grows in medium 3. X grows only in medium 3 and Y grows only in medium 2. Therefore X and Y can be differentiated between W and Y, only Y grows in medium 2 and not in medium 1 or 3 which is suitable for W. Between W and X, X grows in only medium 3. Unlike W which also grows in medium 1. Therefore the biologist cannot actually differentiate between T and Z. Because medium 1 is unsuitable for both and 2 and 3 are suitable for both types.