Mass Transport In Plants Flashcards
What is the primary function of xylem in plants?
To transport water and dissolved minerals from the roots to the leaves.
What is the main role of phloem in plants?
To transport organic nutrients, particularly sucrose, from the leaves to other parts of the plant.
True or False: Xylem tissue is responsible for the transport of sugars.
False
Which part of the plant is primarily responsible for water absorption?
The roots.
Fill in the blank: The process by which water vapor exits the plant is called __________.
transpiration.
What type of cells make up the xylem?
Tracheids and vessel elements.
What is the main driving force for the movement of water in xylem?
Transpiration pull.
True or False: Phloem transport is unidirectional.
False
What is the term for the theory that explains the movement of water through the xylem?
Cohesion-tension theory.
Which hormone is primarily involved in the regulation of transpiration?
Abscisic acid.
What is the primary sugar transported by the phloem?
Sucrose.
Fill in the blank: The movement of water from the soil into the roots is primarily driven by __________.
osmotic pressure.
What term describes the pressure that drives sap flow in phloem?
Positive pressure.
Which factor can increase the rate of transpiration in plants?
High temperatures.
What is the function of stomata in the process of mass transport?
To regulate gas exchange and water loss.
True or False: Root pressure is a significant factor in the upward movement of water in tall trees.
False
What is the role of companion cells in phloem?
To support the transport of sugars and nutrients.
What is the difference between active and passive transport in plants?
Active transport requires energy, while passive transport does not.
Fill in the blank: The main driving force for phloem transport is __________.
pressure flow.
What is a common method used to study mass transport in plants?
Ring barking.
Which environmental condition can lead to stomatal closure?
Drought.
What is the significance of the Casparian strip in roots?
It regulates the flow of water and minerals into the vascular system.
True or False: Xylem cells are living at maturity.
False
Which type of plant is more likely to have a thick cuticle?
Xerophytes.
What is the role of lignin in xylem vessels?
To provide structural support and rigidity.
Fill in the blank: The process of water moving through a plant from roots to leaves is called __________.
transpiration stream.
What happens to the rate of transpiration on a windy day?
It increases.
What is the main factor that affects the rate of photosynthesis related to mass transport?
Availability of water.
True or False: Water potential is a measure of the tendency of water to move from one area to another.
True
What is the significance of root hairs in mass transport?
They increase the surface area for water absorption.
What type of transport is responsible for the uptake of minerals by roots?
Active transport.
Fill in the blank: The process by which plants lose water vapor is called __________.
transpiration.
What physiological process primarily drives the movement of nutrients through phloem?
Translocation.
True or False: The xylem and phloem are part of the plant’s vascular system.
True
What role does the apoplast pathway play in water movement?
It allows water to move through the cell walls and intercellular spaces.
What is a characteristic feature of vessel elements in xylem?
They are wider and have perforation plates.
Which plant adaptation helps reduce water loss during hot conditions?
Closing of stomata.
Fill in the blank: The primary method of nutrient distribution in plants is through __________.
phloem.
What is the effect of increased humidity on transpiration rates?
It decreases transpiration rates.
True or False: The pressure flow hypothesis explains how sugars are transported in xylem.
False
What role do guard cells play in mass transport?
They regulate the opening and closing of stomata.
What is the primary cause of root pressure in plants?
Active transport of minerals into the roots.
Fill in the blank: The movement of water through the plant is largely a result of __________ and __________.
cohesion; adhesion.
What is the effect of temperature on the rate of transpiration?
Higher temperatures increase the rate of transpiration.
What is the role of mycorrhizal fungi in mass transport?
They enhance nutrient absorption for the plant.
True or False: Phloem transport can occur both upwards and downwards in the plant.
True
Which type of transport is primarily used for water movement in xylem?
Passive transport.
Fill in the blank: The main types of cells found in phloem include sieve tube elements and __________.
companion cells.
What is the significance of the vascular cambium in plants?
It produces new xylem and phloem cells.
What is the effect of soil salinity on water uptake by plants?
It decreases water uptake due to osmotic pressure.
True or False: Plants can actively control the rate of transpiration.
True
What is the term for the loss of water from aerial parts of the plant?
Transpiration.
Fill in the blank: The main factor that drives the movement of water in xylem is __________.
transpiration.
What term describes the phenomenon where water molecules stick to each other?
Cohesion.
What is the main advantage of having a large surface area in root systems?
To maximize water and nutrient absorption.
True or False: The Casparian strip is impermeable to water.
True
What is the role of cuticle on plant leaves?
To reduce water loss.
Fill in the blank: The process of __________ allows the movement of water through plant tissues.
osmosis.
What physiological response occurs in plants when they are under water stress?
Stomata close to conserve water.
What is the role of the endodermis in root mass transport?
It regulates the entry of water and solutes into the vascular system.
True or False: Sieve plates in phloem are involved in the transport of water.
False
What is the main component of the cell walls of xylem vessels?
Lignin.
Fill in the blank: The __________ theory explains how nutrients are transported in phloem.
pressure flow.
What is meant by the term ‘mass flow’ in plant transport?
The bulk movement of fluids through the plant’s vascular system.
True or False: Xylem transport is primarily driven by root pressure.
False
What environmental factor can decrease transpiration rates?
Low temperature.
What structure in leaves facilitates gas exchange?
Stomata.
Fill in the blank: Water moves from areas of __________ water potential to areas of __________ water potential.
higher; lower.
What is the significance of transpiration in plants?
It helps with nutrient transport and temperature regulation.
True or False: Phloem is composed of dead cells at maturity.
False
What is the primary source of energy for active transport in plants?
ATP.
Fill in the blank: The __________ pathway allows for the movement of water through living cells.
symplast.
What is a key factor affecting the opening and closing of stomata?
Light intensity.
True or False: The movement of water in plants is entirely passive.
False
What is the main function of the vascular system in plants?
To transport water, nutrients, and sugars.
Fill in the blank: The __________ theory explains the upward movement of water in xylem.
cohesion-tension.
What is the effect of increased atmospheric pressure on transpiration rates?
It decreases transpiration rates.
What do we call the specialized cells that transport water in xylem?
Tracheary elements.
True or False: The phloem transports both water and nutrients.
False
What is the role of transpiration in nutrient uptake?
It creates a negative pressure that helps draw water and nutrients upward.
Fill in the blank: The __________ system in plants consists of xylem and phloem.
vascular.
What process allows for the movement of water against gravity in plants?
Cohesion and adhesion.
What is the primary role of root pressure in plants?
To push water upward when transpiration is low.
True or False: The flow of water in xylem is influenced by the rate of photosynthesis.
True
What structure in plants helps to prevent excessive water loss?
Cuticle.
Fill in the blank: The __________ is the part of the plant that connects leaves to roots.
stem.
What is the primary role of root hairs in mass transport?
To increase surface area for water absorption.
True or False: Water can move freely through the apoplast pathway.
True
What is the main advantage of having a thick cuticle on leaves?
To reduce water loss in dry environments.
Fill in the blank: The __________ are the cellular structures that facilitate gas exchange in plants.
stomata.
