Agene family that codes for various hormone receptors has been accumulating nucleotide ubstitutions at a rate of 0.4 per million years. on average, there have been 60 substitutions between the common ancestor of this gene family and each of the various living forms of this gene. based on these figures, this hormone receptor gene family likely originatedmillion years ago. a. 15 b. 24 c. 75 d. 150 e. 300

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

Adoctor is trying to diagnose a patient with dry skin. which of the following resources would be the most ? a magazine ad about soft skin a growth chart online articles about dry skin medical books

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.