Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Oxygenated blood is pumped throughout the body and takes deoxygenated blood from the various parts of the body to the lungs for the purification of blood from the impure one for the maintenance of the body temperature and to maintain hydrogen ion concentration. As the birds and the mammals posses double circulatory system where pure and the impure blood remains separate. If the both oxygenated and deoxygenated blood got mixed then the whole blood will be impure and then our body will not survive for so long cause of the impure blood. That’s why the separation of oxygenated and deoxygenated blood is necessary.
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?
What is a neutralisation reaction? Give two examples.
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
Several electric bulbs designed to be used on a 220 V electric supply line, are rated 10 W. How many lamps can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Give reasons
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
If all the waste we generate is biodegradable, will this have no impact on the environment?
What factors could lead to the rise of a new species?
How is the sex of the child determined in human beings?
One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.
What were the limitations of Döbereiner’s classification?