Transport in Plants

Flashcards about Transport in Plants

Why do plants have a less elaborate transport system than animals?

Plants are less active than animals and do not need to be supplied with materials as quickly. Branching allows cells to get oxygen and carbon dioxide directly from the air by diffusion.

What materials do plants need to transport?

They need transport systems to carry water and minerals and food materials made by the plant.

What are vascular plants also known as and why were they so successful?

Vascular plants are also known as tracheophytes, which means 'tube plants'. They dominated terrestrial ecosystems due to their tube-like vascular tissues.

What do xylem vessels and phloem tubes transport?

Xylem vessels transport water and minerals from the roots to the leaves, while phloem tubes carry food materials from the leaves to the rest of the plant.

Describe the structure of Xylem Vessels

Xylem vessels are made up of many hollow cells joined end to end, with no end walls, and run from roots through the stem branching into every leaf. They contain no cytoplasm or nuclei, and their walls are made of cellulose and lignin helping to keep plants upright.

Describe the structure of Phloem Tubes

Phloem tubes are made of cells with end walls (sieve plates) that have not completely broken down, called sieve tube elements, each with a companion cell to provide requirements.

Vascular Bundle

A group of xylem vessels and phloem tubes.

Where is the vascular bundle located in roots versus shoots?

In roots, vascular tissue is at the center, whereas in shoots, vascular bundles are arranged in a ring near the outside edge.

How do plants take in water from the soil?

Plants take in water from the soil through their root hairs, and the water is carried up the xylem vessels to all parts of the plant.

How do root hairs absorb water?

Water gets into a root hair by osmosis, diffusing down its concentration gradient through the partially permeable membrane.

Transpiration

Transpiration is the evaporation of water from a plant.

Transpiration Stream

Water is constantly taken from the top of the xylem vessels to supply the cells in the leaves reducing the effective pressure at the top of the xylem vessels so that water flows up them.

List Conditions That Affect Water Transportation Rate

Temperature, humidity, wind speed, light intensity, and water supply.

Storage Organ

Any part of the plant that has been modified to store energy (in the form of starch), nutrients, and water for future growth.

Why is food stored in Plants?

Overcome the need for continuous food manufacture, provide food reserves for periods of scarcity, like during drought or low temperature, and provide food reserves for special functions

Food Reserves for Special Functions

Succulent or juicy fruits, store mainly sugars to attract animals that use the fruits as a food source, aiding in seed dispersal. The cotyledons of seeds store starch, proteins and lipids to provide energy.

Bulbs, Storage Roots, Tubers

Examples of Storage Organs

What do storage organs store individually?

Nutrients, Water or Food, Carbohydrates

Vegetative Organs Storage

Include Rhizomes, Stem Tubers, Corms Root tubers, Tap Roots Bulbs Underground Stems Roots Underground Leaves