Plant Biology: Root Functions and Systems

Questions and Answers

What are the four primary functions of roots?

Absorption of water and inorganic nutrients, anchoring the plant body, storage of food and nutrients, transport and conduction of water, hormones, and minerals.

Distinguish between a primary root vs a lateral/branch root.

Primary roots originate from the embryonic root and grow downward, while lateral roots extend horizontally from the primary root.

Distinguish between a taproot vs fibrous root system and which plants are most likely to have each.

Taproot systems have a main root that grows downward, found in dicotyledonous plants. Fibrous root systems consist of thin, branching roots, common in monocotyledonous plants.

Why do tropical trees have shallow root systems?

Rainforest soil is poor and nutrients are at surface level, so shallow roots help absorb nutrients before they are washed away. Signup and view all the answers

Define adventitious roots.

Roots produced on internodes or other parts of plant organs above the soil surface. Signup and view all the answers

What takes place in the region of cell division, cell elongation, and cell maturation? In which region are root hairs found and why?

Cell division features active cell division; cell elongation pushes roots forward; cell maturation forms root hairs to increase nutrient absorption. Signup and view all the answers

Why are root hairs important?

They form a surface over which plants absorb most of their water and nutrients. Signup and view all the answers

What are the various functions of the root cap and mucigel?

Root cap protects cells and mucigel lubricates soil, binds roots to soil, mobilizes nutrients, and attracts beneficial microbes. Signup and view all the answers

What is the rhizosphere?

The soil region close to plant roots with high microbiological activity. Signup and view all the answers

What role do mycorrhizal fungi play in plant growth? Distinguish between ecto vs endomycorrhizal fungi.

Mycorrhizal fungi enhance nutrient absorption; ectomycorrhizal fungi grow on the surface, while endomycorrhizal fungi penetrate the root cells. Signup and view all the answers

Why do some plants form root nodules?

Root nodules house nitrogen-fixing bacteria, which help the plant convert nitrogen and regulate oxygen levels for optimal fixation. Signup and view all the answers

Identify which tissue system the following belong to: epidermis, cortex...

Epidermis: protective outer layer; Cortex: storage and transport of substances. Signup and view all the answers

Study Notes

Root Functions

Roots perform four major functions: absorption of water and nutrients, anchoring the plant, food storage, and transportation of water and minerals to the stem.

Primary Root vs. Lateral Roots

Primary roots originate from the embryonic root and grow downward.
Lateral roots branch out from the primary root, enhancing stability and nutrient absorption.

Taproot vs. Fibrous Root System

Taproot systems have a main root growing vertically, typical in dicots like dandelions and carrots.
Fibrous root systems consist of thin, branching roots, common in monocots and ferns.

Shallow Root Systems in Tropical Trees

Tropical trees possess shallow root systems to quickly absorb surface nutrients in poor rainforest soil, preventing nutrient loss during heavy rains.

Adventitious Roots

Adventitious roots grow from stems or leaves, above ground, aiding in support, stability, reproduction, and anchoring vines.

Cell Regions in Roots

The region of cell division is where active division occurs, while elongation pushes roots through soil.
Cell maturation involves root hair formation, which increases surface area for nutrient absorption.

Importance of Root Hairs

Root hairs significantly enhance a plant's ability to absorb water and nutrients.

Functions of Root Cap and Mucigel

The root cap protects delicate cells, while mucigel facilitates soil penetration, binds soil, mobilizes nutrients, and attracts beneficial microorganisms.

Rhizosphere

The rhizosphere is the soil region near plant roots, rich in microbiological activity, enhanced by organic molecules secreted by root cells.

Role of Mycorrhizal Fungi

Mycorrhizal fungi enhance water and nutrient absorption in exchange for carbohydrates from the plant.
Ectomycorrhizal fungi grow on root surfaces, while endomycorrhizal fungi penetrate root cells.

Root Nodules in Plants

Root nodules, primarily found in legumes, house nitrogen-fixing bacteria, and are pink due to leghemoglobin, which regulates oxygen concentration for efficient nitrogen fixation.

Root Anatomy

Familiarity with various root tissues and their corresponding systems is essential, including epidermis and cortex.

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Description

Explore the essential functions of roots in plants, including water absorption, anchoring, and nutrient transport. Delve into the differences between primary, lateral, taproot, and fibrous root systems. This quiz will enhance your understanding of root structures and their adaptations in various environments.