Why are the sources and effects of pollution difficult to track?

I need help plz

Which of the following is true of microbes? a. ninety-nine percent of all microbes are pathogenic.b. gene expression in bacteria is very similar to gene expression in humans, which facilitates the use of bacteria in recombinant biotechnology and gene therapy.c. all bacterial enzymes are harmful to humans and the environment.d. microbes create pollutants and toxins that harm the environment.

If a human has 23 pairs of chromosomes in every muscle cell of its body how many chromosomes will be in a human egg or sperm

Select the correct answer from each drop-down menu. which phase of mitotic division is the highlighted cell undergoing? the cell is undergoing , which is the stage before .