An important piece of information in the management of a person infected with a chronic virus such as HIV is his/her "viral load" or how many virus particles can be detected. If before PCR, a patient had a viral load of 1.6 x 104 viral particles. What would be the amount of DNA in the sample after the completion of the first PCR cycle?

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

Which of the following is a common response to cell signaling?

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these