Question

1) The simple microscopes used by the earliest practitioners of microscopy contained which of the following?

Select one:

a. Magnifying lens

b. Oil-immersion lens

c. Condenser

d. Ocular

e. Lamp

2) A group of protozoa that are not motile are the ______.

Select one:

a. amoebas

b. ciliates

c. trophozoites

d. Plasmodium sp.

e. dimorphics

3) One technique for staining bacteria for viewing under the microscope is called the Gram stain. In this technique, alcohol is used as a decolorizer because it degrades the outer membrane found in some bacteria. What chemical component of the cell does alcohol affect?

Select one:

a. Protein

b. Carbohydrate

c. Lipid

d. Nucleic acids

4) Why do some animal viruses have an external envelope, while bacteriophages never do?

Select one:

a. Some animal viruses bud out, taking part of the plasma membrane with them, whereas phages always lyse the host bacterial cell when they exit.

b. When bacteriophages bud out, the plasma membrane is beneath the cell wall and therefore cannot be removed.

c. When animal cells are lysed, part of the plasma membrane attaches to the virus; in bacterial cells, it is covered by the cell wall.

d. When phages bud out of the host bacterial cell, they take with them part of the cell wall which forms the capsid, not an envelope.

Answer 1

ANSWER.

1) a. Simple microscope used by the earliest practitioner of microscopy

        contain magnifying lens.

2) d. Group of protozoa that are not motile are the Plasmodium sp.

3) c, Alcohol is lipophilic so it affect the lipid component of the cell.

4) a. Some animal viruses have an external envelop because some

        animal virus bud out,taking part of the plasma membrane with them

        where as phages always lyse the host bacterial cell when they exit.