1) A class collected water samples from a nearby pond and wants to observe the samples for microorganisms. Which microscope would be the most appropriate for the students to use?
A. Dissecting microscope
B. Compound light microscope
I
C. Transmission electron microscope
D. Scanning electron microscope

Compound light microscope

Explanation:

This is the ideal microscope because it requires the passage of  harmless beam of light through the specimen.Since the pond contain living creatures this is best to use.

C and D both require the transmission of beam of electrons through a sample. D depends on the reflection of the electron  after scanning the specimen surfaces and sent this to the lenses of the observer.(C)involved the  passing of the beam of electrons through the specimen the interaction of the electrons with the atoms in the specimen(,therefore in both cases  these specimens can not be wet and living.

The specimen should be dry in both cases and therefore non -living ,because the chamber for the specimen must be a vacuum,and living organism can not survive in the vacuum. Thus pond water can not be used as specimen because the specimen in the water but me be living.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure