Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
Diffusion is a slow process and is insufficient to meet the requirements of the multi- cellular organisms like humans. Human beings are the multi- cellular organisms and have complex body structures. All the body cells do not contain direct contact with the environment, so they need the oxygen and oxygen requirement cannot fulfil by the diffusion process.
So, in the multi- cellular organisms like human beings they have special types of tissues and the organs which helps them to meet the oxygen requirement of the body.
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 are outside raw materials used for by an organism?
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?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
State Fleming’s left-hand rule.
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?
Ethane, with the molecular formula C2H6 has
(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.
What are the functions performed by the testis in human beings?
In the Modern Periodic Table, which are the metals among the first ten elements?
What are the problems caused by the non-biodegradable wastes that we generate?