The correct answer is: physical activity.
Basal energy expenditure is defined as the amount of oxygen (O2) which is consumed while resting and fasting, extrapolated to 24 hrs. Basal energy expenditure is used to determine an individual's caloric needs and it depends on gender, age, activity..
I think its b not sure tho
Protoplasm is what the living material inside a cell called
Scientist study index fossils so they will get an understanding of what life was like back then.
This is a biome.
Biomes really do cover large areas, for example there is one biome stretching from France to central Russia (temperate broadleaf forrest). They are characterized by a similar soil and a shared community of animals and plants.
