Why is vegetative propagation practised for growing some types of plants?
Vegetative propagation occurs without seeds. The lower plants reproduce vegetatively through budding, fission, fragmentation, buds, spores etc. Every part of the plant such as roots, stems, leaves and buds takes part in vegetative propagation and can give rise to same new plants. Plants which have superior traits are vegetatively propagated cause they can give rise to identical plants. Vegetative propagation is of two types:-
Natural vegetative propagation
Artificial vegetative propagation
Vegetative propagation is the only method of reproduction in those plants who lost their capacity to produce seeds, eg. Banana, oranges, rose etc. Vegetative propagation can be done by plant tissue culture for the production of disease free plants.
Why is variation beneficial to the species but not necessarily for the individual?
Draw a labelled diagram of the longitudinal section of a flower.
What are the functions performed by the testis in human beings?
Why does menstruation occur?
How will an organism be benefited if it reproduces through spores?
Asexual reproduction takes place through budding in
(a) amoeba.
(b) yeast.
(c) plasmodium.
(d) leishmania.
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
How does the embryo get nourishment inside the mother’s body?
What is the importance of DNA copying in reproduction?
How does reproduction help in providing stability to populations of species?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
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?
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 determines the rate at which energy is delivered by a current?
What would be the electron dot structure of carbon dioxide which has the formula CO2?
What are the limitations of extracting energy from—
(a) the wind? (b) waves? (c) tides?
How is a voltmeter connected in the circuit to measure the potential difference between two points?
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be –
(a) 1:2 (b) 2:1 (c) 1:4 (d) 4:1
Why should we conserve forests and wildlife?
How is oxygen and carbon dioxide transported in human beings?
How are the lungs designed in human beings to maximise the area for exchange of gases?
Compare the above system with the probable systems in hilly/mountainous areas or plains or plateau regions.
The xylem in plants are responsible for
(a) transport of water. (c) transport of amino acids.
(b) transport of food. (d) transport of oxygen.