Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? See Concept 13.2 (Page) View Available Hint(s) Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? See Concept 13.2 (Page) They need meiosis if the cells are producing organs such as ovaries. They need only meiosis if they produce egg cells. They need both if they are producing plant gametes. They need only mitosis to make large numbers of cells such as sperm. A single-celled organism only needs mitosis.

Which best describes a rhinovirus? o a. a virus that causes a common cold o b. a protective shell around a virus o c. a tube the comes off a virus o d. a piece of dna transferred by a virus

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.

What are the three types of counseling established by marine corps policy?