Ninety-five percent of all living organisms were killed by the deadliest mass extinction in history. It is known as the what mass extinction.

Why does salad become soggy and wilted when the dressing has been on it for a while? Explain in the terms of osmosis.

You are given two white powdery substances. how would you use solubility to identify them?

Which part of the plant cell directs the cell activities including reproduction?

Rheumatic heart disease develops because of an antigen-antibody reaction several weeks after an untreated staphylococcal infection. True / False.

Which of the following phyla have representatives that exhibit radial symmetry throughout their entire lives? A. Cnidarians B. Mollusks C. Arthropods D. Annelids

Marks: 1 the circulatory movement that occurs in a gas or fluid with areas of differing temperatures due to the variation of the density and the action of gravity is called:

there is 30 percent more what in earth's atmosphere today than there was before the start of the industrial revolution

Scientists say that conditions must be "just right" for a hurricane to start up. Which is the first step of "just right" in the development of a hurricane? A) Cool ocean water replaces warmer surface water.

What is another name for a tropical savanna?

What is a substance in plant sources that cannot be digested that is 5 letters