How is oxygen and carbon dioxide transported in human beings?
Exchange of the gases – oxygen and carbon dioxide, take place in various ways in the human beings.
Transport of the oxygen occurs in the two forms:- one is in the form of solution, dissolved oxygen in water and about 3% of the solution present in the plasma. And, another form is oxyhaemoglobin, about 97 percent of oxygen diffuses from plasma into the red blood cells and it loosely joins with iron of haemoglobin to form oxyhaemoglobin and then it combines with one oxygen molecule.
Carbon dioxide transport is carried by the blood in the three forms:- physical solution, bicarbonate ions and carbaminohemoglobin. About 7% of the carbon dioxide dissolves in the plasma and serve as a physical solution. In the bicarbonate ions 70% carbon dioxide released by tissue cells, diffuses into the plasma and then into the red blood cells. Carbon dioxide combines with water to form carbonic acid by the carbonic anhydrase enzyme, then this acid splits into bicarbonate and hydrogen ion. And, they are joined by the sodium and potassium to maintain pH of the blood. And about 23% of the CO2 enters into the red blood cells and combines with amino group of the reduced Hb (haemoglobin) to form carbaminohemoglobin.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What criteria do we use to decide whether something is alive?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
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 outside raw materials used for by an organism?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What are the components of the transport system in highly organised plants?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
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?
State the principle of an electric generator.
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?
How would these advantages differ from the advantages of using a long-term perspective in managing our resources?
How has the traditional use of wind and water energy been modified for our convenience?
How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
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.
People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?
How is the concentration of hydroxide ions (OH-) affected when excess base is dissolved in a solution of sodium hydroxide?
Which of the following constitute a food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
Give two important uses of washing soda and baking soda.