1 Some plants can be grown in water using the technique of hydroponics. The roots are in water and
supplied with the ions that they need at the concentrations that support maximum growth. Some
ions can be absorbed both by diffusion and by active transport.
(a) (i) State two features of diffusion that do not apply to active transport.

Which of the following is true of metabolism in its entirety in all organisms? a) metabolism depends on a constant supply of energy from food. b) metabolism uses all of an organism's resources. c) metabolism consists of all the energy transformation reactions in an organism. d) metabolism manages the increase of entropy in an organism.