Page 99 - Science Class 07

i The stem xylem tubes are connected to the leaves of the plants forming a continuous pipe of
cells.
i The movement of carbohydrate to different parts of the plants is called translocation.

i Plants absorb water from the soil continuously. A small amount of this water is used up by
plants in the process of photosynthesis and the rest of water is lost from the plants through
transpiration.
i Transpiration creates low pressure in upper portion of the plants that helps in transportation
of water and minerals upward.
i When the rate of absorption is lower than the rate of transpiration, the leaves of the plants are
droped down and start wilting.

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A. Tick (3) the correct op on.
1. Transporta on system is also called:
(a) Transpira on system (b) Vascular system
(c) Osmosis (d) Respiratory system
2. In diffusion, water:

(a) moves from high concentra on to low concentra on
(b) move from low concentra on to high concentra on
(c) does not move at all
(d) none of these
3. In this process, water molecules move from a region of lower concentra on to a
region of higher concentra on.

(a) Diffusion (b) Osmosis
(c) Imbibi on (d) Transporta on
4. Transpira on creates low pressure in _________________ por on of the plants.

(a) lower (b) upper
(c) middle (d) none of these
B. Fill in the blanks.
1. Xylem tubes are made of ____________ cells and transport water and minerals salts only
in an upward direc on.
2. Phloem tubes transport ____________ made by photosynthesis from the leaves to
growing area of the plant and to food storage area.
3. ____________ are present in the form of dissolved salts in the soil.

4. When water and minerals salts enter the cells, they ____________ and become turgid.
5. ____________ wil ng occurs in the region where soil is deficient in water.
6. ____________ creates low pressure in upper por on of the plants.

Science-7 99