You are given a 50 g sample of a gray mineral with a metallic luster and easily visible ortho-rhombic crystals. You are able to scratch it with your thumbnail, but doing so requires a considerable amount of pressure. When you suspend it in water from a spring scale, the spring scale reads 39 g. It leaves a gray streak on a porcelain tile. What mineral is this probably a sample of?

Chlorophyll is found in plant leaves and absorbs light from the sun to enable plants to perform photosynthesis. magnesium is an important component of chlorophyll. the concentration of magnesium ions is higher in the root-hair cells of plants than in the soil. which mechanism of ion uptake would best enable a plant to produce a steady supply of chlorophyll? osmosis diffusion passive transport active transport

There are specialized producers that live in warm water vents deep in the ocean. these producers do not per-form from photosynthesis, but instead perform a similar process with iron and other chemicals. why do you think these producers use this process instead of photosynthesis?

How does the study of genetic disorders such as pku biologists understand normal alleles?