Iii. Which two substances need to be supplied to the muscles in larger amounts during exercise? a) Glucose.
b) Lactic acid.
c) Oxygen.
d) Urea.

Exit what always affects measurement error in an experiment? a. investigator bias b. variability in nature c. instrument precision d. misreading the instrument

Which direction does the energy flow in this energy pyramid ?

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water.b. they use chlorophyll and oxygen to make carbon dioxide and water.c. they use sunlight, water, and carbon dioxide to make sugars.d. they use sunlight, water, and oxygen to make chlorophyll.