Previous Next

Problem : Describe the two types of vascular tissue that are found in tracheophytes.

The two kinds of vascular tissue in tracheophytes are called xylem and phloem. The xylem of vascular plants consists of dead cells placed end to end that form tunnels through which water and minerals move upward from the roots (where they are taken in) to the rest of the plant. Phloem, which is made up of living cells, carries the products of photosynthesis (organic nutrients) from the leaves to the other parts.

Problem : What does "TATC" stand for, and what is its presumed function?

TATC stands for transpiration-adhesion-tension-cohesion, which is the mechanism that scientists think pulls fluid upward from the roots through the xylem.

Problem : In plants, water potential is responsible for moving fluids from one cell to another. What are the two components of water potential?

The two components of water potential are 1) the differences in osmotic concentration (concentration of solute) between two regions and 2) the differences in water pressure (created because of the rigidity of plant cell walls).

Problem : Name and describe the two mechanisms by which water can move from the root surface to the xylem at the core.

One pathway for water is the symplast, in which water moves across the root hair membrane and through the cells themselves, via channels that connect their contents. With the apoplast pathway, on the other hand, water travels along cell walls and through intercellular spaces (instead of through the cytoplasm of neighboring cells).

Problem : What happens to water in the vascular system once it reaches the leaf?

The water either evaporations through the stomata of the leaf (transpiration) or is passed into the phloem along a water potential gradient.
Previous section Next section

Take a Study Break