Plant Roots and Their Functions Quiz

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Questions and Answers

What is one of the primary functions of roots in plants?

Photosynthesis

Storage of nutrients (correct)

Producing flowers

Generating energy

What percentage of the total plant dry weight can roots account for?

15-25%

30-50% (correct)

70-90%

50-70%

Which type of roots are formed from stem tissue instead of root tissue?

Adventitious roots (correct)

Tap roots

Storage roots

Fibrous roots

What do roots primarily absorb from the soil?

Water and dissolved nutrients Signup and view all the answers

What is the role of roots in providing support to plants?

Anchorage Signup and view all the answers

What type of water use is observed in spring wheat during peak conditions?

7 mm per day Signup and view all the answers

What is one factor that roots help plants resist during environmental stress?

Lodging Signup and view all the answers

Which type of roots develop radiating support structures above the soil surface?

Prop roots Signup and view all the answers

Which type of root system includes a primary root that becomes thicker and deeper?

Tap root system Signup and view all the answers

What is the primary function of root nodules in plants like Medicago italica?

Fixing nitrogen from the atmosphere Signup and view all the answers

What characteristic distinguishes the roots of Asteraceae family plants?

Development of a tap root and lateral roots Signup and view all the answers

Which source is credited with the image of sugar beet harvest?

Pixabay Signup and view all the answers

In the context of root systems, what does the term 'mycorrhizae' refer to?

Symbiotic association between fungi and plant roots Signup and view all the answers

What type of relationship do legumes and Rhizobium form?

Symbiotic relationship Signup and view all the answers

What do Rhizobium colonies in legumes form?

Nodules Signup and view all the answers

Which of the following plants is typically inoculated with Rhizobium?

Peas Signup and view all the answers

What is the primary function of the radicle in seed germination?

Providing water and nutrients Signup and view all the answers

Which type of root system is formed by dicot plants?

Tap root system Signup and view all the answers

What must be ensured when storing Rhizobium inoculants?

They are kept alive and within expiration date Signup and view all the answers

What type of bacteria is Frankia?

Nitrogen-fixing bacteria Signup and view all the answers

What color are the nodules formed by Rhizobium in legumes?

Pinkish Signup and view all the answers

From which part of the plant does the secondary root system develop?

Crown Signup and view all the answers

What structure protects the tip of the root?

Root cap Signup and view all the answers

What is the primary function of root hairs?

Absorb water Signup and view all the answers

How do root hairs primarily take up water?

Osmosis Signup and view all the answers

What is the area behind the apical meristem responsible for cell enlargement called?

Zone of elongation Signup and view all the answers

What process allows the root cap to penetrate hard soils?

Cell elongation Signup and view all the answers

Which tissue in the root is responsible for transporting water to the rest of the plant?

Xylem Signup and view all the answers

What happens to the cells in the area of cell maturation?

They specialize into specific tissues/organs Signup and view all the answers

What is the significance of root storage in biennial plants?

It provides energy for winter survival and growth in spring. Signup and view all the answers

What happens if biennial plants are cut late in the year?

It increases the likelihood of winter kill. Signup and view all the answers

Which of the following crops is a biennial root crop?

Radish Signup and view all the answers

What is done to the sugar beet after harvesting?

The root is washed, shredded, and crushed. Signup and view all the answers

What type of plants perform nitrogen fixation?

Legumes Signup and view all the answers

What can the pulp remaining after juice extraction from sugar beet be used for?

It is a rich food for domestic animals. Signup and view all the answers

During which season are sugar beets typically harvested?

Fall Signup and view all the answers

Which of the following is NOT categorized as a biennial plant?

Cabbage Signup and view all the answers

Study Notes

Plant Organs: Roots

Roots make up one-third to half of a plant's total dry weight.
Roots are vital for several functions including absorption, anchorage, storage, and nitrogen fixation.
Roots need an extensive contact area with soil particles to absorb water and dissolved nutrients.
Roots need oxygen for respiration.

Absorption

Roots absorb water and dissolved nutrients.
Plants need significant amounts of water; for example, spring wheat in southern Alberta requires 420-480 mm of water annually.
Roots absorb simple minerals (e.g., N, P, K, S) and organic substances from decaying matter (vitamins, hormones).

Anchorage

Roots provide stability and support to plants.
Anchorage allows effective photosynthesis.
Environmental factors like wind and rain necessitate anchoring.
Poorly developed roots lead to lodging in susceptible plants.
Adventitious roots, those from stem tissue not roots, provide additional support.
Corn has a unique anchoring system called "prop roots."

Storage

Biennial, perennial, and winter annual plants rely on root storage for survival through winter and subsequent growth.
The plant stores food in its roots at the end of the growing season.
Stored food provides energy for shoot growth in the spring.
Alfalfa requires sufficient root storage, so late harvest can hinder winter survival.
Other root crops for storage include carrots, beets, turnips, and radishes (though not potatoes).
Biennial root crops, such as beets, carrots, and radishes, are harvested during their first year of growth to utilize stored food rather than for seed production.

Root Crops

Common harvested biennial root crops include sugar beets, carrots, and radishes.

Sugar Beet

An important root crop grown in southeastern Alberta for its sugar content.
Harvested in the fall of the year they are planted.
Tops are used as animal feed, and the root is washed, shredded, and processed into sugar.
Sugar produced from sugar beets is similar to sugarcane sugar.

Nitrogen Fixation

Nitrogen fixation occurs in legumes (plants that have their seeds in true pods).
Legume roots form relationships with rhizobium bacteria.
Examples of legumes include peas, soybeans, lentils, chickpea, and alfalfa.
Frankia is a nitrogen-fixing genus of bacteria found in actinorhizal plants—various trees and shrubs in Canada.

Rhizobium (Nitrogen Fixation)

Rhizobium bacteria live within the roots of legume plants.
Rhizobium form colonies in root nodules.
Rhizobium helps plants use nitrogen obtained from the air.
Nitrogen is necessary for plant growth.
Farmers often use inoculation with Rhizobium to enhance soil nitrogen for successful legume crop growth.
Rhizobium viability is temperature-dependent.

Inoculation

When planting peas, lentils, and alfalfa, seeds are inoculated with Rhizobium bacteria for better nitrogen use.
Rhizobium, usually mixed with peat, is applied to the seeds.
Special care is required during Rhizobium handling to maintain its viability.

Monocot and Dicot Roots

Monocot roots differ from dicot roots developmentally.
Dicot roots often have a main tap root, with secondary roots originating from it.
In contrast, monocot roots primarily comprise a fibrous system of branching roots.

Root Development

The radicle, the embryonic root, emerges first from the seed allowing germination to absorb nutrients and water.
Smaller seminal roots develop simultaneously (i.e., side roots).

Tap Roots/Dicot Plants

Dicots have a major, primary root from which numerous secondary roots arise.
Examples include alfalfa.

Fibrous Roots/Monocot Plants

Monocot roots develop from a crown (just below the soil surface), quickly producing fibrous (branched) roots.
Examples include onions.

Crown

The crown is the area of plant stem or roots just below the soil surface.

Root Hairs

Root hairs expand the surface area for improved absorption and efficient water uptake.
Water and nutrients are absorbed through root outer layers and transported to the xylem.
Root hairs are fragile and easily damaged, so precautions during transplanting are necessary.

Water Uptake

Root hairs absorb water via osmosis.
Water moves through outer root layers transporting to xylem in the centre.
Xylem transports water to the shoot and the plant.

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Description

Test your knowledge on the critical functions of roots in plants with this quiz. Explore topics including root composition, types of roots, and their roles in plant support and water absorption. Perfect for students studying botany or plant biology!