Astudent wants to answer the question "does adding calcium powder to soil make pea plants grow faster? " she adds calcium powder to the soil of 12 plants and does not add it to the soil of a second group of 12 plants. she measures the growth of all of the plants in each group for a month. which statement best summarizes the factors that need to be controlled in this experiment?
a) all plants should be the same age and health and be given equal amounts of water and sunlight.
b) all plants should be placed in separate, equal-sized pots on the same table, where they receive the same amount of sunlight.
c) all plants should be watered in the morning at the same time each day, and given the same amount of soil and sunlight.
d) all plants should be the same health and be given equal amounts of water, calcium, and sunlight.

The many volcanoes located along the edge of the pacific ocean make up the ring of fire. how does subduction play a role in the volcanic activity in the ring of fire?

Consider darwin's first writings on the theory of natural selection. an important point of darwin's essay on the principle of population, written in 1798, was a peer's observation that in nature plants and animals produce far more offspring than can survive, this observation can be attributed to a) charles lyell. b) thomas malthus. c) jean-baptiste lamarck. d) johann friedrich meckel.

18. determine whether each stateme blank space given. ach statement is true (t) or false (f). place your answer in the 8. when a cell is put into an isotonic solution, individual wat put into an isotonic solution, individual water molecules cannot move back and forth across the cell membrane. d. when a cell is put into a hypertonic solution, there is a net movement of water molecules across the cell membrane into the cell. c. when a cell is put into a hypotonic solution, there is a net movement of water molecules across the cell membrane out of the cell. d. the movement of any solvent across a semi-permeable membrane is called osmosis. e. carrier proteins have the ability to change shape and physically move molecules across the cell membrane. f. in facilitated diffusion, the concentration of the molecules to be moved across the cell membrane is higher inside the cell.