What dis the difference between auttoroph and heteroph?

The seed coat's most important function is to provide a) a nonstressful environment for the megasporangium. b) the means for dispersal. c) dormancy. d) a nutrient supply for the embryo. e) desiccation resistance.

Why do we perceive objects as retaining their brightness under different lighting levels?

What element is able to combine with itself and hydrogen to form large molecules ?