5. a)
Explain root pressure with the help of an experiment.
b)
(OR)
Write an experiment conducted by F. W. Went to show the influence of
hormones at the apex of coleoptile.
Reproduction?
Answers
Answer:
Water from soil reaches xylem vessels of the root. because of the osmotic pressure gradient and from there it rises up due to pressure. The pressure which causes water to rise up in xylem is called root pressure. It is a vital pressure which pushes water upwards. This is possible when cortical cells alternately pulsate. This root pressure can be understood through a simple experiment.
Experiment: Take a well-watered potted plant and cut the main stem to 7cm above the soil surface and join the cut end of the stem with a glass tube. with the help of a rubber tube joint. Fill some water in a glass tube up to the fixed mark.
Make the rubber joint airtight by applying molten wax, or grease. Keep the apparatus for an hour or so. It will be observed that water in the glass tube is rising. The rise in a glass tube is due to root pressure. which pushes up the water from root to stem. The magnitude of root pressure is not much.
Answer:
Explain root pressure with the help of an experiment.
b)
(OR)
Write an experiment conducted by F. W. Went to show the influence of
hormones at the apex of coleoptile
Explanation: