Q27 of 30 Page 1


(i) Identify any two parts from the above diagram which carry oxygenated and deoxygenated blood.


(ii) Explain the process of double circulation with the help of a flow chart


(i) The pulmonary artery (labelled as C) carries deoxygenated blood to the lungs and the pulmonary veins (labelled as F) carry oxygenated blood from lungs back to the heart.

(ii) The process of double circulation is as follows:


a) The deoxygenated blood pumped by the right ventricle enters the pulmonary artery and the oxygenated blood is pumped into the aorta by the left ventricle.


b) The deoxygenated blood pumped into the pulmonary artery is then carried on to the lungs from where the oxygenated blood is then carried by the pulmonary veins to the left atrium.


This is known as Pulmonary circulation.


c) The oxygenated blood is carried by arteries, arterioles and capillaries to the tissues and from these tissues, deoxygenated blood is collected veins and vena cava and passed into the right atrium.


This is known as the Systemic circulation.


The blood goes through the heart twice during each cycle and this is known as double circulation.



More from this chapter

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25

(I)Metal X is found in nature as its sulphide XS. It is usedin the galvanisation of iron articles. Identify the metal X.How will you convert this sulphide ore into the metal?Explain with equations.

OR


(II)State the reason for the following:


(i) Aluminium oxide is called anamphoteric oxide.


(ii) An iron strip dipped in a blue copper sulphatesolution turns the blue solution pale green.


(iii) Hydrogen gas is not evolvedwhen most metals react with nitric acid.


(iv) Calcium does not occur in freestate in nature.


(v) Sodium or potassium metals are kept immersed underkerosene.


 26

The formulae of four organic compounds are given below:


(i) Which one of these compounds A, B, C or D is a saturated hydrocarbon?


(ii) Identify the organic acid and give its structural formula.


(iii) Which ofthe above compounds when heated at 443K in the presence of concentrated forms ethene as the major product? What is the role played byconcentrated in this reaction? Also write the chemical equationinvolved.


(iv) Give a chemical equation when B and C react with each other


in presence of concentrated. Name the major product formed andmention one of its important use.


 28

(i) Describe the various steps involved in the process of binary fission with the help of a diagram.

(ii) Why do multicellular organisms use complex way of reproduction?


OR


(i) Describe the role of prostate gland, seminal vesicle and testes in the human male reproductive system.


(ii) How is the surgical removal of unwanted pregnancies misused?


(iii) Explain the role of oral contraceptive pills in preventing conception.


 29

(i) Consider a conductor of resistance ‘R’, length ‘L’, thickness’ d’ and resistivity ‘ρ’. Now this conductor is cut into four equal parts. What will be the new resistivity of each of these parts? Why?

(ii) Find the resistance if all of these parts are connected in:


(a) Parallel


(b) Series


(iii) Out of the combinations of resistors mentioned above in the previous part, for a given voltage which combination will consume more power and why?