Plant Transport Systems Quiz

Xylem is a type of vascular tissue in plants that transports water and dissolved minerals from the roots to the leaves.

Phloem is another type of vascular tissue that transports sugars and other organic compounds produced during photosynthesis from the leaves to other parts of the plant.

Lignin is a complex polymer that strengthens and waterproofs cell walls, particularly in xylem vessels. This makes them rigid and prevents water loss.

Xylem vessels are long, hollow tubes formed from dead cells joined end to end. They are specialized for efficient water transport.

The end walls of xylem cells dissolve, creating a continuous tube, allowing water to move freely from the roots to the leaves. This process is known as transpiration.

The process of transporting food nutrients (like sucrose and amino acids) from where they are made (leaves) to where they are needed (all other plant cells).

The movement of water and dissolved minerals upwards from the roots to the leaves.

The area of the plant where sugars are made, primarily the leaves.

The area of the plant where sugars are used for growth, respiration, and storage. Think of roots, flowers, and growing tips.

The movement of water and dissolved minerals is unidirectional, meaning it only moves upwards.

The movement of food sugars and amino acids can happen in both directions.

Xylem vessels are long, continuous tubes formed by joining cells end-to-end, with no cross walls. This structure allows water to flow freely from the roots to the leaves.

Lignin, a strong and rigid substance, makes up the walls of xylem vessels. Lignin provides structural support, preventing the vessels from collapsing and ensuring efficient water transport.

Xylem cells are dead, lacking cell contents, which allows for unrestricted water flow through the vessel. The absence of cross walls creates a continuous passage for water movement.

Water enters the root hair cells by osmosis, a process where water moves from a region of high water concentration (soil) to a region of lower concentration (root cells). This movement is driven by the water potential gradient.

Water moves from cell to cell within the root, driven by osmosis. As water enters a cell, its water potential increases, creating a gradient that forces water into the next cell.

Water vapor evaporating from a leaf creates a low pressure at the top of the xylem, pulling water upwards from the roots. This pressure difference, along with cohesion and adhesion forces, drives the transpiration stream.

Transpiration is the loss of water vapor from plant leaves through the stomata. Evaporation from mesophyll cells creates water vapor, which diffuses out of the stomata.

The strong attraction between water molecules (cohesion) and between water molecules and the xylem vessel walls (adhesion) helps move water up the transpiration stream. Cohesion helps maintain a continuous water column, while adhesion prevents water from falling back down.

Transpiration is essential for transporting mineral ions from the roots to the leaves. These ions are dissolved in water and carried along with the transpiration stream.

Transpiration helps maintain turgor pressure in plant cells, providing structural support and keeping stems and leaves erect. Water loss due to transpiration creates suction forces that pull water into the cells, maintaining turgidity.

Transpiration provides water for photosynthesis in leaf cells. Water is a key reactant in the process of photosynthesis, providing the required hydrogen atoms for sugar production.

Transpiration helps cool the plant down. As water evaporates from the leaves, it absorbs heat from the surrounding environment, helping to regulate the plant's temperature.

Light intensity, humidity, air movement, and temperature influence the rate of transpiration. Changes in these factors affect the rate of water evaporation from leaves, directly impacting transpiration.

When a plant loses more water through transpiration than it can absorb from the roots, its cells lose turgor pressure, becoming flaccid and causing wilting. Wilting is a sign of water stress in plants.

Xerophytes are plants adapted to survive in arid environments with limited water availability. They have modifications that minimize water loss, such as long roots, reduced leaf surface area, and thick, waxy cuticles.