Why is it significant that pollen contains a multicellular male gametophyte instead of just male gametes? The non-gamete cells of the male gametophyte provide protection from desiccation and UV radiation. The non-gamete cells of the male gametophyte control the growth and development of the pollen tube. The non-gamete cells of the male gametophyte provide nutrition that supports the development of the embryo. The non-gamete cells of the male gametophyte undergo meiosis.

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.

Any sound above what db can cause hearing loss in human beings

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?