roots Flashcards
What is the importance of roots in plants?
Roots provide stability and anchorage, ensuring plants remain stable and upright. They also play a crucial role in growth and development by absorbing nutrients and water.
What unique growth examples demonstrate root stability?
Roots can grow over obstacles like decomposing tree trunks and can hold trees above the ground after a fallen tree decomposes.
How do roots contribute to plant growth?
Roots absorb nutrients and water, which are essential for shoot growth. A higher surface-to-volume ratio increases absorption efficiency.
What are the different types of roots?
Types of roots include taproots and fibrous roots, which cater to various functions and adaptations.
What are the main functions of roots?
Roots provide anchorage and support, store carbohydrates, aid in reproduction, and offer protection and competition.
What is an example of carbohydrate storage in roots?
Fleshy taproots store energy during winter.
Examples include carrots, radishes, and beets.
What is the taproot system?
The taproot system originates from the radicle in seeds, forming a large primary root with lateral branches.
Examples include carrots, cassava, and sweet potatoes.
What is the fibrous root system?
The fibrous root system is composed of many similarly sized roots and increases absorption and transport efficiency.
An example is Gladiolus.
What is the role of the root cap?
The root cap protects the delicate meristematic tissue as the root pushes through the soil.
What are the zones of growth in roots?
The zones include the root cap, zone of elongation, and zone of maturation.
What is the function of root hairs?
Root hairs increase the surface area for absorption of water and nutrients.
What is the endodermis?
The endodermis is the innermost layer of the cortex, regulating the flow of water and dissolved substances into the vascular cylinder.
What is the Casparian strip?
The Casparian strip is composed of lignin and suberin in the endodermal cells, blocking apoplastic transport of water and solutes.
What is the difference between the symplast and apoplast pathways?
The symplast pathway involves interconnected cytoplasm of cells, while the apoplast pathway allows free movement through cell walls.
What is the vascular system of plants responsible for?
The vascular system transports water, minerals, and sugars throughout the plant.
What distinguishes eudicot vascular systems from monocot vascular systems?
Eudicot vascular tissue forms a ring structure, while monocots have scattered vascular bundles.
What are storage roots?
Storage roots in some plants store nutrients during favorable seasons, ensuring survival through dormancy.
What are prop roots?
Prop roots are adventitious roots that provide extra support, commonly seen in monocots like corn and eudicots like banyan trees.
What are pneumatophores?
Pneumatophores are specialized aerial roots that facilitate gas exchange in waterlogged environments.
What are aerial roots?
Aerial roots are found in orchids and are covered with velamen for water retention.
What are contractile roots?
Contractile roots help anchor the plant and are found in bulbs and corms.
What are pneumatophores?
Specialized aerial roots produced by some plants in waterlogged environments, facilitating gas exchange for submerged roots.
Example: White mangrove (Laguncularia racemosa).
What are aerial roots?
Roots found in orchids, covered with velamen for water retention.
What are contractile roots?
Roots found in bulbs and corms that help anchor the plant and adjust its depth in the soil.
Example: Hyacinths, bulbs.
What are mycorrhizae?
Mutualistic associations between plant roots and fungi that enhance nutrient uptake, especially phosphorus.
What are the two types of mycorrhizal relationships?
Ectomycorrhizae and Endomycorrhizae.
What is ectomycorrhizae?
Fungal hyphae that penetrate the outermost root cortex but do not enter the plant cells.
What is endomycorrhizae?
Fungal hyphae that penetrate the root cortex and cell walls, forming structures called arbuscules inside the plant cells.
What are root nodules?
Specialized structures formed by the division of root cortex cells that house nitrogen-fixing bacteria.
What is the role of Rhizobium in root nodules?
Converts atmospheric nitrogen into ammonia, which is essential for plant growth.
What are haustorial roots?
Parasitic roots that penetrate host vascular tissue to extract nutrients.
What do haustorial roots do?
Invade the host plant’s tissues, forming a continuous vascular connection to extract nutrients.
