Plant Structure & Growth
These tiny extensions on roots increase surface area for absorption.
What are root hairs?
The main driving force for water entering root cells.
What is osmosis
Plants detect light, gravity, and touch through these types of cells.
What are sensory receptor cells
This tissue in leaves is the main site of photosynthesis
What is mesophyll (ground tissue)?
Vascular bundles in stems and leaves contain these two main transport tissues.
What are xylem and phloem?
This gas is needed for photosynthesis but can increase water loss.
What is CO₂?
These compounds are produced to defend plants against herbivores.
What are secondary metabolites?
The inside of a plant cell is charged ____ compared to the outside.
What is negatively?
In this type of growth, plants increase in length at tips.
What is primary growth?
This type of phloem cell loads sugar into sieve tubes.
What are companion cells?
In plant signaling, these three steps are similar to animal nervous system responses.
What are sensing, processing, and responding?
Small leaves and thick cuticles are examples of these adaptations.
What are structural adaptations to reduce water loss?
This type of meristem is found at shoot and root tips.
What is the apical meristem?
Describe why maintaining low sucrose concentration in sink cells is important.
It ensures a concentration gradient for sugar to keep flowing from source to sink.
Describe the function of systemin in plant defense.
Systemin signals cells to produce defensive proteins when the plant is wounded.
Predict what might happen if stomata stayed permanently open.
The plant would lose too much water and could wilt or die.
Predict how root growth might change if soil nutrients were unevenly distributed.
Roots would grow more toward areas with higher nutrient concentrations
Predict what would happen if a plant could not pump H⁺ ions out of its root cells.
Nutrient uptake would be severely impaired because proton gradients drive ion transport.
Describe the mechanism plants use to open and close stomata.
Opening: K⁺ ions enter guard cells, water follows → cells swell. Closing: K⁺ exits, water leaves → cells shrink.
Predict how root structure might change in a nutrient-poor soil.
Roots may become longer, thinner, or branch more to explore more soil volume.