1. A widely accepted explanation for the transport of sugar in phloem is called
A. root pressure theory
B. transpiration
C. pressure flow hypothesis
D. cytoplasmic streaming
2. Phloem is composed of
A. vessel elements and companion cells
B. tracheids and vessel elements
C. sieve-tube elements and companion cells
D. tracheids and sieve-tube elements
3. The movement of most minerals, including potassium into root cells is by
A. osmosis
B. diffusion
C. bulk flow
D. active transport
4. The evaporation of water from leaves is called
A. transpiration
B. cohesion
C. tension
D. pressure flow
5. Normally CO2and O2enter a plant by
A. osmosis
B. active transport
C. diffusion
D. evaporation