The symbiotic relationship between nitrogen-fixing bacteria and leguminous plants involves complex signaling and structural modifications in the root. Which of the following accurately describes the role of NOD factors in this interaction?
Plant hormones that promote bacterial growth within root nodules
Bacterial signals that trigger root hair curling and cortical cell division
Enzymes produced by the plant to break down bacterial cell walls
Proteins that transport nitrogen from bacteria to plant cells
Related Questions
A root was described as adventitious root because it
developed from a stem cutting
grew downwards into the soil
absorbed water and minerals
developed from the radicle
A researcher observes that a particular plant species exhibits significantly reduced root hair development when grown in a hydroponic solution lacking phosphorus. Which physiological role of phosphorus in root hair formation is MOST likely affected?
Major component of cell wall cellulose
Cofactor for enzymes involved in lignin biosynthesis
Nucleic acid synthesis and energy transfer for cell division and elongation
Regulation of stomatal closure to prevent water loss
Pneumatophores are positively
Positively geotropic
Negatively geotropic
Positively hydrotropic
Negatively phototropic
A plant species adapted to waterlogged conditions exhibits aerenchyma formation in its roots. Which of the following BEST explains the adaptive advantage of this anatomical modification?
Increases root surface area for enhanced water absorption
Provides structural support to prevent root collapse in saturated soil
Facilitates oxygen transport to submerged root tissues, enabling aerobic respiration
Stores excess water for use during periods of drought
Which specific tissue within the root endodermis is primarily responsible for regulating the passage of water and minerals into the stele, and how does its structure facilitate this function?
Pericycle; its meristematic nature allows for selective uptake
Cortex; its large intercellular spaces facilitate diffusion
Casparian strip; suberin deposition in cell walls blocks apoplastic pathway
Phloem; its active transport mechanisms selectively move nutrients
Which of the following BEST explains the physiological significance of the quiescent center in the root apical meristem?
Promotes rapid cell differentiation to form specialized root tissues
Acts as a reserve of stem cells, protecting the meristem from damage and ensuring continuous growth
Synthesizes hormones that inhibit root elongation and promote branching
Regulates the uptake of water and nutrients from the soil
Which of the following plants has haustorial roots?
Pea
Trapa
Lily
Cuscuta
A mutant plant exhibits stunted root growth and reduced gravitropic response. Microscopic analysis reveals disorganized columella cells in the root cap. Which of the following is the MOST likely cause of this phenotype?
Increased production of cytokinin in the root tip
Disruption of amyloplast sedimentation and auxin redistribution
Overexpression of genes involved in cell elongation
Enhanced sensitivity to ethylene
The symbiotic relationship between nitrogen-fixing bacteria and leguminous plants involves complex signaling and structural modifications in the root. Which of the following accurately describes the role of NOD factors in this interaction?
Plant hormones that promote bacterial growth within root nodules
Bacterial signals that trigger root hair curling and cortical cell division
Enzymes produced by the plant to break down bacterial cell walls
Proteins that transport nitrogen from bacteria to plant cells
