Which of the following procedures should be followed prior to placing a specimen slide on the stage of the microscope?

a. turn the objective lens to the lowest magnification setting.
b. focus the microscope on the light source.
c. close the diaphragm so no light can enter.
d. spit on the eyepiece to make sure that it is clean.

B) so it can fit on the stage of the microscope.

Explanation:

mark brainliest !!

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

answer; i believe the correct answer is (a)0