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.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation: