At the end of the third half-life, 5.25 grams of a radioactive material remains. What was the total amount of radioactive material at the start? 42
84
21
20

Maria wanted to grow a fern in her backyard. acting on a suggestion from a friend, she collected brown dots from the underside of a fern's leaves and then potted them. after a few days, maria saw small fern leaves erupting from the pot. which statement explains this phenomenon? a. the fern transitioned from gametophyte generation to sporophyte generation. b. the fern grew as a result of mitosis. c. the fern transitioned from sporophyte generation to gametophyte generation. d. the fern grew to be genetically identical to its parent plant.

Control of the body is accomplished by which of the following body systems? nervous system and circulatory system endocrine and repertory system circulatory and respiratory systems nervous system and endocrine systems

You are observing different types of cells in your science lab. one cell has many chloroplasts. what is the most likely function of this cell? a. energy production b. photosynthesis c. reproduction d. digestion