water is drawn into the root hair cells by osmosis; due to the presence of dissolved substances in the cell sap of root hairs, the concentration of cell sap is greater than that of the surrounding solution in the soil/concentration gradient; this exerts a higher osmotic pressure, thus drawing the water molecules across the cell wall and cell membrane into the root hair cells; more water drawn into the root hair cells dilutes the cell sap; making it less concentrated than that in the adjacent cortex cell of the root; due to osmotic gradient, water moves from the adjacent cells to the next by osmosis; until it enters the xylem vessels located in the center of the root; the xylem vessels of the root then conduct the water up into the xylem vessels in the stem into the leaves; there is a force in the roots which pushes water up the stem; this force is known as root pressure; and can be considerably high in some plants; energy from the endodermal cells of the root is responsible for driving this force; in the xylem vessels, water would rise up by capillarity; to some extent because the vessels are narrower and there is a high attractive force between the water molecules and the cell walls; the cohesive; and adhesive forces are important in the maintenance of a continuous and uninterrupted water column in the xylem vessels up the tree to the leaves; water vaporizes from the spongy mesophyll cells; their cell sap becomes concentrated than the adjacent cells. This increases the osmotic pressure of the spongy mesophyll cells; as a result of this, water flows into the cell from other surrounding cell, which in turn takes in water from xylem vessels within the leaf veins; this creates a pull/suction force that pulls a stream of water from xylem vessels in the stem and roots. This force, known as transpiration pull; helps in maintaining a continuous column of water from the roots to the leaves; water flows from the midrib into leaf veins from where it enters leaf cells; from the mesophyll cells, it enters the airspaces; then the substomatal air chambers; from where it evaporates through the stomata; to the atmosphere.
Edwinnyongesa8 answered the question on December 6, 2018 at 03:50
- Describe the adaptations of the nervous system to its functions(Solved)
Describe the adaptations of the nervous system to its functions
Date posted: December 6, 2018. Answers (1)
- State the economic importance of members of Monera and Fungi and for each economic importance name a suitable or appropriate organism(Solved)
State the economic importance of members of Monera and Fungi and for each economic importance name a suitable or appropriate organism
Date posted: December 6, 2018. Answers (1)
- Describe the process of mitosis(Solved)
Describe the process of mitosis
Date posted: December 4, 2018. Answers (1)
- Describe how the various supportive tissues in plants adapt them to their habitats(Solved)
Describe how the various supportive tissues in plants adapt them to their habitats
Date posted: December 4, 2018. Answers (1)
- Discuss Lamarck’s and Darwin’s theories of evolution(Solved)
Discuss Lamarck’s and Darwin’s theories of evolution
Date posted: December 4, 2018. Answers (1)
- Describe the process of secondary thickening in a woody stem
(Solved)
Describe the process of secondary thickening in a woody stem
Date posted: December 4, 2018. Answers (1)
- What is secondary growth(Solved)
What is secondary growth?
Date posted: December 4, 2018. Answers (1)
- Which organelle is most abundant in white blood cell?(Solved)
Which organelle is most abundant in white blood cell?
Date posted: November 13, 2018. Answers (1)
- Explain how altitude affects the rate of breathing(Solved)
Explain how altitude affects the rate of breathing.
Date posted: November 8, 2018. Answers (1)
- Explain how mammals regulate their body temperature and relate this to their body size(Solved)
Explain how mammals regulate their body temperature and relate this to their body size
Date posted: November 7, 2018. Answers (1)
- Name 5 characteristics of phylum platyhelminthes?(Solved)
Name 5 characteristics of phylum platyhelminthes?
Date posted: November 7, 2018. Answers (1)
- Giving specific examples; explain the forms of aneuploidy in animals.(Solved)
Giving specific examples; explain the forms of Aneuploidy in animals.
Date posted: November 5, 2018. Answers (1)
- What is the difference between glycosuria and hyperglycemia?(Solved)
What is the difference between glycosuria and hyperglycemia?
Date posted: October 31, 2018. Answers (1)
- Describe the events that take place from the time when a mature pollen grain lands on stigma until formation of fruits and seeds(Solved)
Describe the events that take place from the time when a mature pollen grain lands on stigma until formation of fruits and seeds.
Date posted: October 30, 2018. Answers (1)
- Define the following in relation to reception, response and coordination in plants and animals (a) Irritability (b) response (c) Stimulus (Solved)
Define the following in relation to reception, response and coordination in plants and animals
(a) Irritability
(b) Response
(c) Stimulus
Date posted: October 28, 2018. Answers (1)
- State two reasons why accumulation of lactic acid acid [in animal cells, produced from pyruvic acid through anaerobic respiration, in “power” exercises e.g. sprinting]...(Solved)
State two reasons why accumulation of lactic acid acid [in animal cells, produced from pyruvic acid through anaerobic respiration, in “power” exercises e.g. sprinting] leads to an increase in the rate of the heart beat.
Date posted: October 27, 2018. Answers (1)
- State and explain four chromosome structure and variation.(Solved)
State and explain four chromosome structure and variation.
Date posted: October 24, 2018. Answers (1)
- Discuss the double helix structure of DNA(Solved)
Discuss the double helix structure of DNA.
Date posted: October 23, 2018. Answers (1)
- State and explain characteristics of genetics material(Solved)
State and explain characteristics of genetics material.
Date posted: October 23, 2018. Answers (1)
- Define gene regulation and state five reasons why gene activity is regulated in a cell(Solved)
Define gene regulation and state five reasons why gene activity is regulated in a cell.
Date posted: October 21, 2018. Answers (1)