Chapter 11: Transport in Plants

Minerals are taken by the roots from the soil and are transported to various parts of the plants wherever needed via the xylem vessels. The mineral requirement is not the same for all plants and neither for all plant parts so all the parts of the plants do not get the same amount of minerals.

Exudates’ analysis would help to find minerals and in the form that they are mobilised in the plant because exudates are often planted sap which contains xylem sap as well as phloem sap.

Using a plant growth hormone called cytokinins that help delay senescence or ageing of plant parts.

Placing the cut stem immersed in water in the vase to not allow water cavitation to occur by air.

Solution coming soon.

a) All the essential substances in living organisms are solutes dissolved in water and transported from one place to another.

b) Specific heat is the amount of heat required to increase the temperature of one gram of matter by one degree rise in temperature

c) Surface tension is the cohesion of the water molecules on the fluid surface of occupying the least volume. Viscosity is the resistance of a fluid to flowing water.

d) Water expands when its temperature becomes lesser than 4◦C. This decreases its density and making ice float.

e) Water rises in capillary tubes which is a property that helps transport of water from roots of the plants to other parts of the plant.

Animal cells have ATP powered pumps like the Na+- K+ pump where 3Na+ is sent out in exchange of 2 K+ ions thus increasing the level of K+ ions in the intracellular region. This is how via the pumps, ion concentration is maintained higher intracellularly than in the extracellular region.

Beetroot loses colour only when it is placed in hot water as the plasma membrane of the cells denatures at high temperature

In a girdled plant, when water is supplied to the leaves above the girdle, leaves may remain green for some time because leaves have the capability of synthesizing their food by photosynthesis using water and CO2 from the air.

Plants also require mineral nutrients and charged ions like potassium, sodium, etc. which cannot be transported via simple diffusion because the cell membrane which is selectively permeable does not allow large, polar and charged particles through.

Plants usually shrink when the rate of transpiration exceeds the rate of absorption of water by roots. So if we use anti-transpirants like Abscisic acid then it checks the rate of transpiration.