Sand dollars are radially symmetrical and have an internal skeleton but no backbone. Which phylum do sand dollars belong in?

A) chordates

B) echinoderms

C) arthropods

D) mollusks

In eukaryotic cells, the timing of the cell cycle is regulated by ... A) Centrioles B) Cyclins C) Spindle fibers D) The nuclear envelope

Why can't a damaged cell in the brain be replaced?

What is the diploid chromosome number for your karyotype

What is the most likely outcome of a disease that kills off the long-spined sea urchins on a reef? A. Staghorn coral cover will increase. B. Star coral cover will increase. C. Sponge cover will increase. D. Algae cover will increase.

What organelle is necessary for your to make your own food in photosynthesis?

How does the amount of uranium in zircon tell us how old the crystal is?

Which organism's are omnivores? A) The snake, the bear, and the fish B) The fish and the eagle C) The bear and the fish D) The snake and the mouse If an omnivore is an animal that eats both plants and animals, I'd choose D because all the other

How are all humans similar?

Why does earth have such a diversity of plant and animal life? give three reasons.

After sequencing a molecule of dna, you discover that 20% of the bases are cytosine. what percentage of the bases would you expect to be thymine? explain why.