. Your lab technician was to determine the ash content of buttermilk by conventional dry ashing. The technician weighed 5 g of liquid buttermilk into one weighed platinum crucible, immediately put the crucible into the muffle furnace using a pair of all stainless steel tongs, and ashed the sample for 48 h at 800 °C. The crucible was removed from the muffle furnace and set on a rack in the open until it was cool enough to reweigh. (4 marks)

a. What errors were made in the preceding method (there were several)?

b. What were the likely results of these errors?

*will mark brainliest for first correct answer* which of the following is most likely to affect the biodiversity of a park ecosystem? a. less rain than usual for several months b. ongoing pollution from a nearby factory c. park rangers plant a new type of tree d. disease wipes out an entire population

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.

How did alexander fleming’s research solve a societal problem? he developed ways to treat inherited diseases. he advocated for regular hand washing to kill germs. he discovered a new type of medicine that could treat infections. he discovered the cause of mad cow disease, an emerging disease.