| Class XI |
Biology |
Biology |
14 |
data given in the table clearly indicates a concentration gradient for oxygen from alveoli to blood and blood to tissues. Similarly, T ABLE 14.1 Pa... |
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| Class XI |
Biology |
Biology |
14 |
of the respiratory rhythm centre. Neural signal from this centre can reduce the duration of inspiration and thereby alter the respiratory rate. A c... |
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| Class XI |
Biology |
Biology |
14 |
between deoxygenated blood and alveoli, transport of these gases throughout the body by blood, exchange of O and2CO betwee2 the oxygenated blood an... |
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| Class XI |
Biology |
Biology |
14 |
of the brain and a chemosensitive area in the medulla can alter respiratory mechanism. Reprint 2026-27 192 B IOLOGY E XERCISES 1. Define vital capa... |
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| Class XI |
Biology |
Biology |
15 |
BODY FLUIDS ANDC IRCULATION 193 C HAPTER 1 5 B ODY F LUIDS AND C IRCULATION 15.1 Blood You have learnt that all living cells have to be provided wi... |
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| Class XI |
Chemistry |
Chemistry Part-I |
6 |
rate of evaporation= rate of condensation H O(l) H O (vap) For any pure liquid at one atmospheric 2 2 pressure (1.013 bar), the temperature At equi... |
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| Class XI |
Biology |
Biology |
15 |
Erythrocytes or red blood cells (RBC) are the most abundant of all the cells in blood. A healthy adult man has, on an average, 5 millions to 5.5 mi... |
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| Class XI |
Biology |
Biology |
15 |
for immune responses of the body. Platelets also called thrombocytes, are cell fragments produced from megakaryocytes (special cells in the bone ma... |
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| Class XI |
Biology |
Biology |
15 |
as well as the other groups of blood. Therefore, such persons are called ‘universal recipients’. Reprint 2026-27 196 BIOLOGY 15.1.3.2 Rh grouping A... |
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| Class XI |
Biology |
Biology |
15 |
This is a mechanism to prevent excessive loss of blood from the body. You would have observed a dark reddish brown scum formed at the site of a cut... |
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| Class XI |
Biology |
Biology |
15 |
ventricle to the aorta which is carried to all the body tissues and the deoxygenated blood from there is collected by the veins and returned to the... |
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| Class XI |
Biology |
Biology |
15 |
the lymph. Lymph is a colourless fluid containing specialised lymphocytes which are responsible for the immune responses of the body. Lymph is also... |
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| Class XI |
Biology |
Biology |
15 |
fluid which is circulated. Heart, the mesodermally derived organ, is situated in the thoracic cavity, in between the two lungs, slightly tilted to ... |
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| Class XI |
Biology |
Biology |
15 |
thelowerleftcorneroftherightatriumclosetotheatrio-ventricularseptum called the atrio-ventricular node (AVN). A bundle of nodal fibres, atrioventric... |
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| Class XI |
Biology |
Biology |
15 |
the closure of tricuspid and Reprint 2026-27 200 BIOLOGY bicuspid valves due to attempted backflow of blood into the atria. As the ventricular pres... |
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| Class XI |
Biology |
Biology |
16 |
the glomerular blood flow and thereby the GFR back to normal. A comparison of the volume of the filtrate formed per day (180 litres per day) with t... |
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| Class XI |
Biology |
Biology |
15 |
easily heard through a stethoscope. The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas the sec... |
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| Class XI |
Biology |
Biology |
15 |
Vessels—the arteries and veins. Basically, each artery and vein consists of three layers: an inner lining of squamous endothelium, the tunica intim... |
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| Class XI |
Biology |
Biology |
15 |
the rate of heart beat, the strength of ventricular contraction and thereby the cardiac output. On the other hand, parasympathetic neural signals (... |
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| Class XI |
Biology |
Biology |
15 |
transport essential substances to the cells and to carry waste substances from there. Another fluid, lymph (tissue fluid) is also used for the tran... |
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| Class XI |
Biology |
Biology |
16 |
EXCRETORY P RODUCTS AND THEIRELIMINATION 205 C HAPTER 1 6 E XCRETORY P RODUCTS AND THEIR E LIMINATION 16.1 Human Animals accumulate ammonia, urea, ... |
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| Class XI |
Biology |
Biology |
16 |
uricotelic animals. Reprint 2026-27 206 B IOLOGY A survey of animal kingdom presents a variety of excretory structures. In most of the invertebrate... |
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| Class XI |
Biology |
Biology |
16 |
in between the Reprint 2026-27 EXCRETORY PRODUCTS AND THEIRELIMINATION 207 medullary pyramids as renal columns called Columns of Bertini (Figure 16... |
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| Class XI |
Biology |
Biology |
16 |
juxta medullary nephrons. The efferent arteriole emerging from the glomerulus forms a fine capillary network around the renal tubule called the per... |
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| Class XI |
Mathematics |
Mathematics |
10 |
we have 2 1 2 = – 4a (–3), i.e., a = 3 Therefore, the equation of the parabola is x = − 4 y, i.e., 3x = – 4y. EXERCISE10.2 In each of th... |
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