problem 1) All of the following statements are true but which one is the most precise?
Water is conducted through plant stems in
(a) the xylem, (b) vascular bundles, (c) vessels, (d) veins.
problem 2) Which of the following statements is the most correct?
(a) Food can travel up the stem in a phloem.
(b) Food can travel down the stem in a phloem.
(c) Food can travel up or down the stem in a phloem.
(d) Food can travel up or down the stem in a xylem.
problem 3) Roots have no chlorophyll and grow in darkness. Thus how do roots get their food?
problem 4) Which of the following conditions is least likely to increase rate of transpiration in a plant?
(a) a rise in temperature
(b) an increase in humidity
(c) increased air movement
(d) increased sunlight
problem 5) Which of the following statements are true of transpiration
(a) it draws water up a stem
(b) it draws dissolved salts up a stem
(c) it draws food up a stem
(d) it has a cooling effect on a leaves
(e) it speeds up photosynthesis?
problem 6) Osmosis and transpiration both play a part in the movement of water through a plant. Which of these two processes makes the greater contribution to the movement of water up the trunk of a tree?
problem 7) Which of the following statements are true?
A potometer is an apparatus which can be used to:
(a) measure the rate of water uptake in a shoot
(b) measure the rate of transpiration in a shoot
(c) measure the rate of photosynthesis in a shoot
(d) compare rates of transpiration in different conditions
problem 8) Most of the water taken up by the plant passes through it and is evaporated to the atmosphere. What use is made of the tiny fraction of this water which is retained by the plant?
problem 9) A student set up a potometer in the laboratory and measured the rate of movement of water in the capillary. An average of four readings gave a rate of 50mm per minute. The apparatus was then taken outside, where there was a light breeze. Four more readings were taken without delay. The average of these readings was 130 mm per minute.
The student concluded that exposure of the shoot to rapid air movement had increased the rate of transpiration.
Criticise the design of the experiment and the student's conclusions.
problem 10) The drawing on the right represents a design for a potometer. Criticise the design and practicability of the apparatus.