How does chemical coordination occur in plants?
Plants do not have nervous or muscular system for movement or responsiveness like animals have. Plants only shows the growth (by growth hormones like phytohormones) with the attached substratum by giving them appropriate soil moisture, favourable environmental or physiological conditions. Various plant hormones are present for the plant growth like auxin, gibberellin, cytokinin, ethylene or abscisic acid.
Auxin is responsible for the growth of the stem, gibberellins are those growth hormones which enhances the long growth of stem according to the plant in the presence of meristematic cells, cytokinin acts on the cell division part of the plant, ethylene is a gas present in atmosphere and mainly responsible for fruit growth or ripening with root initiation ,And abscisic acid is responsible for seed development, stomatal closing, bud dormancy etc.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
What will happen if we kill all the organisms in one trophic level?
Explain why the planets do not twinkle.
Element X forms a chloride with the formula XCl2, which is a solid with a high melting point. X would most likely be in the same group of the Periodic Table as
(a) Na (b) Mg (c) AI (d) Si
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
The magnetic field in a given region is uniform. Draw a diagram to represent it.
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
What can you as an individual do to reduce your consumption of the various natural resources?
What does an electric circuit mean?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Do basic solutions also have H+(aq) ions? If yes, then why are these basic?