,BOT2601 Assignment 1 (COMPLETE ANSWERS)
Semester 1 2025 - DUE March 2025; 100% correct solutions
and explanations.
QUESTION 1
List the cell types concerned with transport of water in
angiosperms, and briefly
explain the differences between these cell types. (10)
In angiosperms, the cell types responsible for the transport of
water are:
1. Xylem Vessels:
o These are long, tube-like cells formed by the end-to-
end fusion of vessel elements. Xylem vessels are dead
at maturity and have large diameters with thick,
lignified walls. The ends of these cells have
perforations, which allow water to flow freely through
the vessel, making them highly efficient for bulk water
transport. They are primarily responsible for the
upward movement of water from the roots to the
leaves.
2. Tracheids:
o Tracheids are elongated cells with tapered ends and
thick, lignified walls, found in the xylem of both
angiosperms and gymnosperms. They have small
openings called pits, which allow water to move from
one tracheid to another. Tracheids are less efficient
than xylem vessels in water transport due to their
narrower lumen and absence of perforations at their
ends.
, 3. Xylem Parenchyma:
o Xylem parenchyma cells are living cells with thin
walls and are responsible for the storage of water and
nutrients. While they don't directly transport water,
they assist in the lateral movement of water within the
xylem and act as storage reservoirs.
4. Xylem Fibers:
o These are long, narrow, and lignified cells that provide
structural support to the xylem. They do not play a
direct role in water transport but help maintain the
rigidity and stability of the xylem tissue as it conducts
water.
Key Differences:
Xylem Vessels vs. Tracheids: Xylem vessels have larger
diameters and end-wall perforations, allowing for faster and
more efficient water movement. Tracheids, with their
tapered shape and pits, conduct water more slowly and are
less efficient.
Function: Xylem vessels are the primary cells for water
transport, while tracheids, though still involved, provide
slower, less efficient water transport.
Presence: Xylem vessels are mainly found in angiosperms,
while tracheids are found in both angiosperms and
gymnosperms.
QUESTION 2
Write explanatory notes on the structure and functions of the
endodermis of roots.
Semester 1 2025 - DUE March 2025; 100% correct solutions
and explanations.
QUESTION 1
List the cell types concerned with transport of water in
angiosperms, and briefly
explain the differences between these cell types. (10)
In angiosperms, the cell types responsible for the transport of
water are:
1. Xylem Vessels:
o These are long, tube-like cells formed by the end-to-
end fusion of vessel elements. Xylem vessels are dead
at maturity and have large diameters with thick,
lignified walls. The ends of these cells have
perforations, which allow water to flow freely through
the vessel, making them highly efficient for bulk water
transport. They are primarily responsible for the
upward movement of water from the roots to the
leaves.
2. Tracheids:
o Tracheids are elongated cells with tapered ends and
thick, lignified walls, found in the xylem of both
angiosperms and gymnosperms. They have small
openings called pits, which allow water to move from
one tracheid to another. Tracheids are less efficient
than xylem vessels in water transport due to their
narrower lumen and absence of perforations at their
ends.
, 3. Xylem Parenchyma:
o Xylem parenchyma cells are living cells with thin
walls and are responsible for the storage of water and
nutrients. While they don't directly transport water,
they assist in the lateral movement of water within the
xylem and act as storage reservoirs.
4. Xylem Fibers:
o These are long, narrow, and lignified cells that provide
structural support to the xylem. They do not play a
direct role in water transport but help maintain the
rigidity and stability of the xylem tissue as it conducts
water.
Key Differences:
Xylem Vessels vs. Tracheids: Xylem vessels have larger
diameters and end-wall perforations, allowing for faster and
more efficient water movement. Tracheids, with their
tapered shape and pits, conduct water more slowly and are
less efficient.
Function: Xylem vessels are the primary cells for water
transport, while tracheids, though still involved, provide
slower, less efficient water transport.
Presence: Xylem vessels are mainly found in angiosperms,
while tracheids are found in both angiosperms and
gymnosperms.
QUESTION 2
Write explanatory notes on the structure and functions of the
endodermis of roots.
