Answer: The correct answer is - 3) olfactory receptors neurons that detect smell. 4) photoreceptors neurons that detect light .
1) and 2) statements are correctly matched in the question..
Olfactory receptors are also called odorant receptors. The olfactory receptor neurons detect smell and thus give a sense of smell to the organism. They are present in the nasal cavity.
Photoreceptor neurons are those that detect light and they are present in the retina of eye.
Answer:
CFU/mL
Explanation:
Given -
a) Number of colonies of bacteria is equal to 
b) Total volume of the solution is equal to
mL
c) Dilution factor is equal to 
As we know that
CFU/mL 
Where N is the number of bacterial colonies, DF is the dilution factor and V is the volume
Substituting the given values in above equation, we get -
CFU/mL 
Explanation:
A hypothesis is defined as an educated guess , while a research question is simplify a research wondering about the world .