1. Fungi in the soil form a symbiotic association with roots. These fungi create a large surface area associated with the root hairs that helps to do which of the following?

a) aid in absorbing minerals and ions
b) maintain turgor in the root epidermal cells
c) provide sugar to the roots
d) anchor the plant

2. Carbon dioxide released by the root hairs helps plants take up positively-charged ions. What process produces the CO2 that root hairs release into the soil?

a) mycorrhizae b) transpiration c) respiration d) photosynthesis

3. Which of the following mechanisms help plant roots acquire negatively-charged ions?

a) proton pumps and co-transporters
b) passive diffusion of the anions along electrochemical gradients
c) small amounts of clay in the soil
d) leaching of ions from soil water