What is the limit of resolution of a microscope using a 100X oil objective with

Question

What is the limit of resolution of a microscope using a 100X oil objective with a numerical aperture of 1, a condenser with a numerical aperture of 2, and 10X ocular objective if you assume the average wavelength of light used is 600 nm? Select one: a. 300 microns b. 200 nm c. 1000 apertures d. 2 microns e. 0.5 nm Why do you start by mixing the bacteria in water and spreading the cells?

Select one:

a. To remove debris from the slide

b. To dilute the stain

c. Decrease cell density

d. To cause slide adherence e. To kill the bacteria

Basic stains are: Select one:

a. Easier to see with a electron microscope

b. Difficult to see with a microscope

c. Colonizing the cells

d. Attracted to the negative charges on the surface of most bacerial cells

e. Fluorescent stains

What is the primary factor for staining time?

Select one

: a. Heat

b. Cell density

c. Cooling time for stain

d. Booze content

e. Stain color

Which one of the following is NOT likely to happen after adding stain to a specimen?

Select one:

a. Add color to specimen

b. Kills the specimen cells

c. Blocks more light from passing through a specimen

d. Adds contrast between the specimen and surroundings

e. Makes the speciment appear larger

Explanation / Answer

I can only answer the biology part.

So starting with why do we mix the bacteria in water and spread the cells, the answer is C (Decrease cell density). As when we mix the cells the cells will spread on the slide. It's easy to see the cells in the microscope when they are spread rather than when they are clustered on one spot.

Basic stains are  Attracted to the negative charges on the surface of most bacterial cells (D). The cell membrane of bacteria are negatively charged while the basic stains are generally positively charged. So, on adding the stain it sticks to the cell membrane, and thus cell gets stained, and we are able to see it.

What is the primary factor for staining time? Booze content (D). The alcoholic content defines how far the stain will penetrate in the cell. More the alcoholic content more the stain will penetrate. Alcohol precipitates the proteins and helps the stain penetrate.

Which one of the following is NOT likely to happen after adding stain to a specimen?

Makes the speciment appear larger (E). A stain never makes the cells appear larger, it only distinguishes the cells from the surroundings.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.