How are water and minerals transported in plants?
Water and minerals are transported through the xylem in plants. Transportation of the water and mineral is the upward movement and is the passive process. Xylem is composed of living and non- living cells. Mainly non- living cells are present, includes tracheary elements- tracheids and vessel elements. Xylem tissue also contains xylem parenchyma cells for storage function and xylem fibres for the mechanical function. Water and minerals from the soil enter into the plant through the root and then through root cortex and finally get passed into the xylem, moves upward into the leaves and the path through which water moves into xylem cells occurs through the apoplast (transport in the cell walls to the intercellular spaces) and symplast (transport occurs from cell protoplast by the interconnection of plasmodesmata) and this upward movement of the water and the minerals from roots to the aerial parts of the plant against the gravitational force through the xylem is known as ascent of the sap.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What criteria do we use to decide whether something is alive?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
What are outside raw materials used for by an organism?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What are the components of the transport system in highly organised plants?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
What evidence do we have for the origin of life from inanimate matter?
Explain the following.
(a) Why is the tungsten used almost exclusively for filament of electric lamps?
(b) Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
(c) Why is the series arrangement not used for domestic circuits?
(d) How does the resistance of a wire vary with its area of cross-section?
(e) Why are copper and aluminium wires usually employed for electricity transmission?
Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
What is hydrogenation? What is its industrial application?
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R′, then the ratio R/R′ is –
(a) 1/25 (b) 1/5 (c) 5 (d) 25
Differentiate between metal and non-metal on the basis of their chemical properties.
Why are carbon and its compounds used as fuels for most applications?
What will happen if we kill all the organisms in one trophic level?
Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.