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" The moment of inertia of a rigid-body about an axis of rotation is numerically equal to twice the kinetic energy of rotation of the body, when rotating with unit angular velocity about that axis.

I = 2(K.E.)

or, K.E. = 1/2 lω².

Yes, moment of inertia change with change of the axis of rotation.

(a) It can be done by adding a strip of blue litmus paper into a tube containing a small amount of sample water if the colour changes into red, this means that some acid has gone into the river. 

(b) The acid has reacted chemically with the drain cover which is usually made of iron. The correct word is corrosion. 

(c) Iron reacts with an acid H₂SO or HCl to evolveH₂ gas. Since the gas is released immediately accompanied by large number of bubbles Fizzing of detain covers is expected.

all the parallels from the north pole to the south pole equally.

There is a change in the shadow of the stick because there is a change in position of the sunrise & sunset.

The duration of day is 12 hours in the month of September because both the hemispheres of the earth are at equal distance from the sun & the equator receives perpendicular rays of the sun.

the farthest point from the sun.

The duration of the day was around 12 hours in the month of September.

the revolution of the earth and the tilt of earth’s axis

(i) The circle of illumination divides all the parallels from the north pole to the south pole equally.

(ii) Everywhere on the earth, the night time and day time are of equal duration. This condition is called equinox.

(iii) Thus, the duration of the day will be twelve hours on equinox.

(i) Seasons occur due to the revolution of the earth.

(ii) Seasons also occur due to the tilt of the earth’s axis of rotation.

(i) The living world on the earth is affected by the cycle of seasons.

(ii) Penguins are native to south pole. Penguins have adapted to the natural conditions prevailing in the Antarctic regions of the south pole.

(iii) Besides predators like polar bears roam within the Arctic Circle. Hence penguins are found at the South pole & not at the North pole.

i. North Pole is receiving sunlight in Fig ‘A’

ii. North Pole is not receiving sunlight in Fig. ‘B’

iii. Northern hemisphere has the longest daytime on 21^st June.

iv. Northern hemisphere will have the largest night in 22^nd December.

v. The Tropic of Cancer will receive perpendicular sunrays on 21^st June.

vi. Summer season will prevail in the northern hemisphere from 22^nd March to 23^rd September.

vii. Summer season prevails in Australia from 23^rd September to 21^st March.

viii. Midnight sun is observable in Norway from 21^st March to 23^rd September. It will be summer in Norway that time.

ix. The midnight sun will be visible at Bharati Research Station of India at Antarctica from 23^rd September to 21^st March. It will be summer season there.

(i) Sunrays are never perpendicular on any of the parallels between Tropic of Cancer & the North pole or between Tropic of Capricorn & the South pole.

(ii) In the period from 23^rd September to 21^st March (Dakshinayan) the region between Antarctic circle and the south faces the sun. The whole of Antarctic Circle falls within the zone of illumination.

We see the apparent movement of the sun from both the northern & southern hemispheres.

i. (b) it appears that the sun moves to the north or south in a year.

ii. (c) different parallels on the earth would have experienced the same climate throughout the year.

iii. (a) the sun starts its southward journey from Tropic of Cancer on 21st June and Northward journey from Tropic of Capricon on 22nd December.

iv. (c) summer and winter.

D) Delta, Loessplain

(i) Seasons have been decided on the basis of the duration of sunlight, equinoxes & solstices.

(ii) The equatorial region receives perpendicular sunray almost throughout the year.

(iii) Hence the climate of that region does not change at all in the year.

(iv) (iii) Hence the effect of the seasons is not experienced in the equatorial region.

the apparent movement of the sun.

the rotation of the earth

(C) 3rd order

the northern and the southern hemisphere

The molten material inside the earth is known as Magma

According to kinetic theory of gases, the pressure exerted by a gas of mass M and volume V or density p is given by 

P = (1/3) M v² /V 

Here n is the number of molecules per unit volume, m the mass of each molecule and v² is the mean of square speed. 

Correct option is (a) Green diamond

From the hilum of a kidney, arises a narrow tube which carries the urine collected in the pelvis of the kidney to the urinary bladder which is situated at the base of the abdomen.

The cells that comprise the loop of Henle are well-adapted for diffusion, filtration and selective re-absorption. The final changes in the composition and the volume of the nephric filtrate occurs in the loop of Henle and the distal convoluted loop of the tubule. Glucose, amino acids, water, mineral salts and some other substances leave the loop of Henle to pass into the blood capillaries that surround it.

A single afferent arteriole of the renal artery breaks up into a number of capillary branches to form the glomerulus. The blood in the glomerulus is subjected to higher pressure since the diameter of the afferent arteriole is wider than that of the efferent arteriole that leaves the glomerulus, so ultra-filtration takes place.

Sphygmomanometer measures

3. Blood pressure

Correct option is (c) The British

Certain animals predominantly excrete urea. Such animals are called ureotelic animals. Man also excretes urea, so he is called ureotelic and this phenomenon is termed as ureotelism.

In humans, urea is formed in -

(b) liver

It is a part of the nephron consisting of glomerulus and the Bowman’s capsule.

(a) Blood platelets are involved in blood clotting or coagulation. Blood platelets integrate at the site of injury to release thromboplastin which initiates the process of blood clotting.

(b) Neutrophils perform phagocytosis i.e. they engulf pathogens that enter the blood stream and destroy them.

(c) Erythrocytes transport oxygen from the lungs to the tissues in the form of an unstable compound oxyhaemoglobin and transport carbon dioxide from the tissues to the lungs.

(d) Lymphocytes produce antibodies against pathogens which enter the blood stream. In some\ cases they also perform phagocytosis.

(e) Bone marrow is involved in formation of RBCS and WBCs. It is also involved in the destruction of old and weak RBCs.

The nephrons have a tubular structure consisting of proximal and distal tubules which reabsorbs all the useful products present in the glomerular filtrate, and the process is called Tubular reabsorption.

The heart is a pump that circulates blood to all parts of the body. It is about the size of a  human fist and located to the left in chest cavity. It has four chambers – two upper  chambers called auricles or atria and two lower chambers called ventricles. The auricles  receive blood from different body parts and ventricles pump the blood out of the heart.  The valves between auricle and ventricle on each side allow blood to flow in one  direction only. Heart acts as a double pump. The right side of the heart carries  deoxygenated blood to the lungs to be oxygenated. The left side of the heart pump  oxygenated blood to the body.

(a) The left ventricle pumps blood to the farthest points in the body such as the feet, the toes and the brain against the gravity. Thus, it requires greater force to push the blood. In order to with stand with the force applied the walls of the left ventricle are thicker than the walls of all the chambers.

(b) The blood from stomach and intestines enters the liver via hepatic portal vein because the liver monitors all the substances that have to be circulated in body. The excess nutrients such as glucose, fats are stores in the liver. Excess amino acids are broken down by the process deamination. Toxic substances are detoxified.

(c) During blood transfusion it is important that the blood groups of the donor and the recipient are compatible. In case of an incompatible blood transfusion, the recipient develops antibodies that attack the antigens present on the RBCs of the donor causing the blood cells to clump together which may result in death. The examination of Rh factor is also necessary for the blood transfusion. Therefore, the blood groups of both the donor and recipient must be known before transfusing blood.

(d) Veins carry the blood from the body part towards the heart while the arteries carry the blood from the heart. Veins carry the blood against the force of gravity. Therefore, only the veins and not the arteries are provided with valves.

(e) Atrial wall is less muscular than the ventricular wall because the major function of atria is to receive blood from the body and pump in into very next ventricles. While the ventricles pump the blood out of the heart. Right ventricle to the lungs and the left ventricle to all the body parts.

(f) Arteries are responsible to carry oxygenated blood from the heart to the tissues. The blood flows in the artery under high pressure and in spurts. If arteries are located superficially then there is a high possibility of their damage which could lead to a lot of blood loss. To prevent this damage and blood loss, the arteries are deep seated in the body.

Dengue fever is one such disease in which the number of platelets get reduced to as low as 25-30 thousands per cubic mm of blood. The major symptoms of dengue are high fever, rashes or red spots on body, nausea or vomiting, pain in abdomen, back, or back of the eyes and muscles.

The haemoglobin is the respiratory pigment which is formed of the iron containing part known as haemin and protein part known as globin. It helps to transport respiratory gases (oxygen).

1. Non-coagulation of blood is called Haemophilia.

2. When oxygen is in fairly high concentration, the haemoglobin quickly combines with it and forms an unstable compound known as Oxyhaemoglobin.

3. The element required for blood clotti ng is Calcium.

4. Thrombocyte helps in blood clotting.

5. The three distinct types of blood ves sels are Arteries, veins and the capillaries.

(a) A is artery, B is vein.

(b) 1- Endothelium of the artery,

2 - Middle layer of smooth muscles and elastic fibres of the artery,

3 - External layer of connective tissue of the artery,

4 - Endothelium of the vein,

5 - Middle layer of smooth muscles and elastic fibres of the vein,

6 - External layer of connective tissue of the vein.

(c) An artery has thick muscular walls and a narrow lumen. It carries blood away from the heart towards any organ. A vein on the other hand has thin muscular walls and a wider lumen. It carries blood away from an organ towards the heart.

The consequences are as follows: 

1) They switched to new type of food and entered new niches. 

2) This lead to arise of diverse variety of beetles as some changes in beetles will take place to make them adaptable to new niches. 

People with blood group O are called universal donors because they can donate blood to all the blood groups. Their red blood cells (RBCs) have no antigens and so cannot be stuck by blood of any other group. 

People with blood group AB are called universal recipients because they can receive blood from all 4 blood groups. The red cells in them have no antibodies and therefore it does not stick with blood from other groups.

5,000,000/mm³  of RBCs in men.

Oxygen is transported by the blood in the form of Oxyhaemoglobin.

(a) The structure 3 represents the heart. It forms the centre of double circulation and is located between the liver and the head (as per the diagram). Also the blood circulation (indicated by 1) begins from heart to lungs.

(b) 

1. Heart: The heart is a muscular organ that pumps blood to all the cells in our body through a network of blood vessels. It pumps the blood and hence helps in circulating oxygen and nutrients to all body parts. The heart pumps deoxygenated blood to the lungs and oxygenated blood to the rest of the body.

2. Blood vessels: Blood vessels are a necessary part of the body’s circulatory system. The blood vessels carry blood throughout the body. Three types of blood vessels are:

1. Arteries: They carry oxygenated blood from the heart to all parts of the body.

2. Veins: They carry deoxygenated blood from the body cells to the heart.

3. Capillaries: They form the connection between the arteries and the veins where exchange of substances takes place.

3. Red blood cells: Red blood cells (RBCs) contain haemoglobin which carries oxygen throughout the body. It also transports nutrients to cells.

4. White blood cells: White blood cells (WBCs) help in fighting infection as they destroy the germs.

5. Platelets: The platelets help in clotting of blood, whenever there is a blood flow due to some injury.

6. Blood: Blood circulates throughout the body and performs the following functions:

• It carries or transports food and oxygen to each body cell.

• It carries away waste products to organs (like kidneys, lungs and intestine) from where they are excreted out of the body.

• It protects the body against infection by destroying germs.

• It helps in blood clotting, thereby preventing excessive blood loss.

• It regulates body temperature.

Phylum-Arthropoda and Phylum-Mollusca.