An ecologist studying productivity in a sample of grasses measures gross primary productivity as 1000 kcal / m2 / yr and autotrophic respiration as 100 kcal / m2 / yr. Based on these calculations, the net primary productivity would be kcal / m2 / yr.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.