What is the principal component of the thickest layer of the skin? a: collagen b: elastin c: mast cells d: phagocytes what is the tough protein that is one of the primary components of bones? e: collagen f: fibrinogen g: peptin h: periosteum what is the role of the proteins actin and myosin? i: attaching bones to bones j: attaching muscles to bone k: contacting the muscles l: storing energy

Astudy was performed on 20 trees to test the effectiveness of a new fertilizer. the results of this specific study is brought into question. what would possibly improve the reliability of the results?

You have a solution that contains phospholipid vesicles in a test tube. these vesicles have phospholipid bilayers, but do not contain any membrane transporters. you add a number of different molecules to the solution, and wait a period of time for them to equilibrate. if you could measure the concentration of each molecule, for which of the following would you expect to measure equal concentrations inside and outside of the vesicles? assume for this question that the overall osmolarity inside and outside the vesicles is the same (that is, there is no appreciable diffusion of water across the membrane). (select two answers) an amino acid with a hydrophobic side-chain a small non-polar molecule a negatively charged ion a small polar molecule a small lipid hormone

Adrought killed all the plants in an agricultural farmland. gradually, due to wind and some birds for. nearby areas, new plants started sprouting l. what stage of succession was taking place in the farmland? a) competition b) nudation c) ecesis d) reaction e) migration