What are outside raw materials used for by an organism?
All the living organisms require energy to live and to maintain life. Plants and animals need various separate raw materials from the outside. Plants need some raw materials as they make their food by their own. These raw materials are as follows:-
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.
Animals feed on the plants as they are the producers plays important role in the food chain extends to the top carnivores. All animals take in food, water and oxygen from the outside according to their complexity and the needs.
Organisms use raw material -
Food as the source of energy, oxygen for the breakdown of food to obtain energy, water is for the digestion and to maintain homeostasis that is internal temperature of the body.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
What criteria do we use to decide whether something is alive?
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 the components of the transport system in highly organised plants?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Where do plants get each of the raw materials required for photosynthesis?
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?
Why is respiration considered an exothermic reaction? Explain.
Why are some patients of diabetes treated by giving injections of insulin?
A person needs a lens of power –5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting (i) distant vision, and (ii) near vision?
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic?
Food cans are coated with tin and not with zinc because
(a) zinc is costlier than tin.
(b) zinc has a higher melting point than tin.
(c) zinc is more reactive than tin.
(d) zinc is less reactive than tin.
Explain the following in terms of gain or loss of oxygen with two examples each.
(a) Oxidation
(b) Reduction
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
How does phototropism occur in plants?
In the Modern Periodic Table, which are the metals among the first ten elements?