Transport in plants

Question 1

State one function of xylem tissue. (1)

Answer 1

transports water (up plant);
transports, minerals / ions, (up plant);
support (plant / stem / shoot);

Question 2

State the function of this spiral band of lignin and explain why it is important that the xylem vessel becomes lignified in this way. (3)

Answer 2

Functions:
F1 (lignin), strengthens / thickens, the (xylem) wall;
F2 waterproofing (wall) / AW;
F3 (improving) adhesion of water (molecules);
F4 (spiral) pattern allows flexibility / stretching / movement;

Explanation:
E1 prevents collapse of xylem;
E2 (water) under tension / at low pressure / negative pressure;
E3 reduces (lateral) loss of water, through wall;
E4 increases capillarity / AW;
E5 prevents stem breaking / AW;

Question 3

Explain the function of the pits in a xylem vessel (2)

Answer 3

(pits) allow water to move, in / out / between, vessel(s);
to bypass blockage;
supply water to other, tissues / (other types) cells / parts of plant;

Question 4

Explain what is meant by the term tissue.

Answer 4

collection / group, of cells (of one or more types);
(cells), working together OR with, common / same, function;
specialised (cells);