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?
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?
What would be the consequences of a deficiency of haemoglobin in our bodies?
You are given kerosene, turpentine and water. In which of these does the light travel fastest? Use the information given in Table 10.3.
Material medium |
Refractive index |
Material medium |
Refractive index |
Air | 1.0003 | Canada Balsam |
1.53 |
Ice | 1.31 | ||
Water | 1.33 | Rock salt | 1.54 |
Alcohol | 1.36 | ||
Kerosene | 1.44 | Carbon disulphide |
1.63 |
Fused quartz |
1.46 | ||
Turpentine oil |
1.47 | Ruby | 1.71 |
Benzene | 1.50 | Sapphire | 1.77 |
Crown glass |
1.52 | Diamond | 2.42 |
How is oxygen and carbon dioxide transported in human beings?
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.
The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below –
I (amperes) 0.5 1.0 2.0 3.0 4.0
V (volts) 1.6 3.4 6.7 10.2 13.2
Plot a graph between V and I and calculate the resistance of that resistor.
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
What are the functions performed by the testis in human beings?
Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor, an 8 Ω resistor, and a 12 Ω resistor, and a plug key, all connected in series.
How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?