The word belongs in a different group than all of the other words in the list.

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.

Which line in the graph above best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during and after a period of exercise? 1.b,2.c,3.a,4.d