True or false a doubled chromosomes has one original and one copy

Which statement best describes the nature of science? a. science discoveries using the latest technology are the most valuable. b. scientific theories and laws are based on beliefs and popular opinion. c. scientific ideas change over time as new information is discovered. d. science is superior to other fields such as art, philosophy, and music. i think its c

The endoplasmic reticulum (er) is an organelle in some cells. in these cells, it is continuous with the nuclear membrane and forms a large part of the cell\'s total membrane. sort the phrases below as describing rough er, smooth er, both, or neither. note: if you answer any part of this question incorrectly, a single red x will appear indicating that one or more of the phrases are sorted incorrectly.1) found in prokaryites and uekaryotys2) involved in protein synthesis3) involve in lipid synthesis4) contains molecular chaperones in lumen5) bound with ribosomes6) involved in toxin or drug metabolism7) large systemot internnected tubules,vesicles, and sacs8) "packages" enzymes in vesicles for secretion.

Which structure in the cardiovascular system connect arteries to veins?