Information you will need: Uranium-238 to Lead-206 - half-life 4.5 billion years
Uranium-235 to Lead-207 – half-life 713 million years
Carbon-14 to Nitrogen – 14 – half-life 5730 years
1) A zircon crystal from a lava flow was examined for geologic age. The
scientists measured the 235U, and 207Pb, and determined that 25% of
the atoms were 235U, and 75% were 207Pb.
b) What is the absolute age of the Lava flow?

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

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.

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