Astudy showed that the mortality risk for human babies goes up as birth weight decreases below the average. another study shows an increase in mortality risk as birth weight increases above the average. what can be said about human birth weight?
it is not a trait, and therefore it is not affected by natural selection.
it is a trait, but is not affected by natural selection.
it is a trait that is shaped by stabilizing selection.

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.

Lymphatic vessels remove excess fluid from tissues. often after mammexront( the surgical procedure to remove of all or part of a breast) the lymphatic vessels draining the arm are damaged. explain a consequence of this damage. what can be done to reduce the symptoms?

Which nucleotide component contains nitrogen