Which of the following organisms are photosynthetic autotrophs? select all that apply.

a. algae
b. plants
c. all bacteria
d. some bacteria
e. arthropods
f. protists

Which of the following molecules can be broken down into simple sugars? a. nucleic acid b. protein c. lipid d. carbohydrate

Brass gets discoloured in air because of the presence of which of the following gases in air? a. oxygen b. hydrogen sulphide c. carbon dioxide d. nitrogen

1. beginning with all chambers of the heart in the "relaxed" phase, describe the cardiac cycle in mammals, with systole and diastole of the atria and ventricles. for each time point in the cycle you select, state the following: • whether the atria and ventricles are contracting or relaxing • whether the av valves and semilunar valves are closed or open • whether the pressure in the atria and ventricles is high or low