Chris is preparing a slide with onion cells on it. what does he put on top of the slide after he stains the cells with iodine.

Use the drop-down menu to complete the statement. an electron in the first energy level of the electron cloud has an electron in the third energy level. a. a lower energy thanb. a higher energy thanc. the same energy as

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c. ozone layer hole d. increase in sea levels