Why are there no plants in the aphotic zone?
A. There is not enough free space to accommodate a
plant colony.
B. There are too many predators, so plants can't survive
long enough to reproduce.
C. There is not enough light for plants to undergo
photosynthesis.
D. There is too much traffic, and plants get trampled
before they can put down roots.

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.

Q: a: in sexually reproducing animals, once fertilization of the egg takes place, the exists as a single cell until cell division begins

Im inn a ! what"s the answer which of the following is one way creativity can scientists? by ensuring they follow the scientific method by increasing the amount of time it takes to complete scientific experiments by making sure they only try things that have already been proven by leading them to ask more questions about the natural world