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.
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?
Describe double circulation of blood in human beings. Why is it necessary?
Name two safety measures commonly used in electric circuits and appliances.
Which of the following terms does not represent electrical power in a circuit?
(a) I2R (b) IR2 (c) VI (d) V2/R
The refractive index of diamond is 2.42. What is the meaning of this statement?
How is the process of pollination different from fertilisation?
Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?
Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal
(d) AgNO3 solution and copper metal.
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
What is meant by power of accommodation of the eye?
How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?