The unstable isotope nickel-59 can be used to date rocks that contain it. Nickel-59 decays into the more stable cobalt-59. The nickel Isotope has a half-life of 76,000 years. Which statement about nickel-59 is true?
ОА.
After 76,000 years, all the nickel-S9 in a rock decays into cobalt-59.
OB. Nickel-59 can only be used to date rocks that are younger than 76,000 years.
Oc. All the nickel-59 stabilizes after it completes one half-life period of 76,000 years.
OD. The amounts of nickel-59 and cobalt-59 remain the same over a half-life period.
OE. The amounts of nickel-59 and cobalt-59 tell how long ago the rock cooled to closure temperature.

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.

Diagram of the evolution of land plants?

Agene editing technology called crispr-cas9 uses cellular machinery to change the cell's genetic material. how might this technology be useful in treating diseases like cancer?