Plants have widespread influences, from food chains to climate change.

Draw a labelled diagram of the internal structure of a seed.

Plants have widespread influences, from food chains to climate change.

Explain the process of water uptake and transport by plants.

a. radicle/embryo root shown tapering to a root tip

b. plumule/embryo shoot shown with embryonic leaves «in a dicot seed» drawn and labelled

    OR

    plumule/embryo shoot shown tapering to a shoot tip «in a monocot seed»

c. seed coat/testa shown with a double line

d. cotyledon/endosperm shown as a large structure «for food storage»

e. embryo shown with both embryo root and shoot visible

Accept any dicot or monocot seed

eg:

Award [1] for any of the structure clearly drawn and labelled

Award mpe only if mpa and mpb have not been awarded and the labelling line points clearly to the plumule or radicle or both.

[Max 3 Marks]

a. roots/root hairs absorb water

b. water is absorbed by osmosis

c. solute concentration inside the root is higher/water potential is lower «than in the soil»

d. due to active transport of ions/minerals into the root

e. transport of water in xylem vessels

f. flow/stream of water from roots to leaves

g. water movement in xylem due to pulling force/transpiration pull/suction/negative pressure potential

h. cohesion/hydrogen bonds between water molecules «allows water to be pulled up in xylem»

i. transpiration in leaves generates tension/pulling forces/suction

j. evaporation of water from «leaf» cell walls

k. adhesion of water to «leaf» cell walls/cellulose creates tension «forces»

Not adhesion to xylem walls in mpk and the adhesion must be linked to creating tension

l. lignin in xylem walls/thickened xylem walls prevent collapse/resist tension

m. «movement of water in xylem is a» passive process

[Max 8 Marks]