Where do plants get each of the raw materials required for photosynthesis?
Photosynthesis is the anabolic process by which green plants (autotrophs) synthesize their own food in the form of glucose or carbohydrates from the simple inorganic compounds like carbon dioxide and water. So, this process is the transformation of light energy into the chemical energy to make their food in their own food,i.e, carbohydrates by green plants.
So, the following raw materials are required like carbon dioxide, water, chlorophyll and sunlight to make complex organic material from the simple inorganic material.
Carbon dioxide:- carbon dioxide is taken up from the atmosphere through the stomata and releases oxygen.
Water:- plants take water from the soil through the roots to the leaves. And, the transportation of water from the soil to the roots and then to the root cortex and then finally transported to the leaves from the stem occurs through the xylem.
Sunlight is obtained from the sun to make the food, necessary for the producers (green plants).
Chlorophyll:- when organisms take carbon dioxide and water from the environment, they use sunlight and convert them into the glucose or oxygen and this is taken up by the chlorophyll.
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?
The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
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.
What is an homologous series? Explain with an example.
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?
Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?
What processes would you consider essential for maintaining life?
Why is respiration considered an exothermic reaction? Explain.
Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
Write equations for the reactions of
(i) iron with steam
(ii) calcium and potassium with water.