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Correct option is B) Eubacteria

A) Arthropods

Correct option is A) Protista

Correct option is A) Monera

If wheat is sown in the kharif season, it will not grow well as plants cannot tolerate too much water of the rainy season.

(a) Crop rotation 

(b) The nitrogen-fixing bacteria present in root nodules of leguminous plants is rhizobium bacteria. Rotation of crops (leguminous and non-leguminous crops) in the same field replenishes the soil with nitrogen naturally and increases the soil fertility.

(b) stem (rhizome) 

(c) Low temperature 

Correct answer is (b) 44

(c) Girls are a carrier but boys normal

Man – 44 + XY.
Woman – 44 + XX.

Conclusion: 50% daughter carrier; 50% daughter normal; 50% son colourblind; 50% son normal.

47 or 48 or 49 chromosomes may be present in Klinefelter’s syndrome.

Correct answer is (b) 45

(a) Half normal sons but half haemophilic sons

(b) Between non-sister chromatids of any bivalent

(a) Phenylalanine hydroxylase

It is an autosomal abnormality which is caused due to one extra 21st chromosome (45 + 2 = 47). It is also called as 21st terisomy or mongolism.

(a) Mutation of the autosomal gene

(c) Amoeba multiple fission

(a) Sporozoa

Correct Answer is : (d) ciliata

Correct answer is (a) emphysema

Correct answer is (c) TV

Correct answer is (b) external respiration

Correct answer is (c) RBCs

1. As the size of an organism increases, its surface area to volume ratio decreases. This means it has relatively less surface area available for substances to diffuse through. 

2. Large multicellular organisms therefore cannot rely on diffusion alone to supply their cells with Substances such as food and oxygen and to remove waste products. Large multicellular organisms require specialized transport system. 

3. In short for the organisms to become active, they must be having complex transport system to bring about their vital functions rapidly.

The respiratory surface, for the efficient gaseous exchange should have the following features:

1. It should have a large surface area.

2. It should be thin, highly vascular and permeable to allow exchange of gases. 

3. It should be moist.

1. Heart failure is caused due to progressive weakening of the heart muscle. This results in the failure of the heart to pump the blood effectively. 

2. Hypertension increase the after load on the heart leading to significant enlargement of the heart. 

3. This finally results in heart failure. 

4. Factors responsible for heart failure are advanced age, malnutrition, chronic infections, toxins, severe anaemia or hyperthyroidism, etc. 

5. Any problem leading to degeneration of heart muscle, may result in heart failure.

1. Atherosclerosis is the deposition of fatty substances and cholesterol on the inner lining of eateries. 

2. This deposition results in the formation of atherosclerotic plaque.

3. It results in the decrease of the lumen of the blood vessels causing increasing resistance for the blood to flow which in turn results in the hypertension. 

4. Atherosclerosis of the coronary arteries results in decrease in the blood flow to the heart muscles. 

5. Due to such condition, coronary heart disease is caused.

1. Electrocardiogram or ECG is the graphic v record of electrical variations produced by the heart during one heartbeat or cardiac cycle. 

2. ECG is taken with the help of an instrument called electrocardiograph or ECG machine. Electrocardiograph records the action potentials generated by the heart muscles.

3. The electrical activity of heart is represented in the form of a graph plotted with time on X-axis against voltage displacement on Y-axis. 

4. A normal ECG is a graph having series of ridges and furrows. There are waves such as P-wave, QRS complex and Twave. 

5. P-wave is a small upwards wave representing impulse generated by SA node. P-wave is caused by atrial depolarization that results in atrial contraction. 

6. QRS-complex wave begins as a downward deflection, continues as a large upright triangular wave and ends’ as a downward wave. 

7. QRS-complex wave represents spreading of impulse from SA node to AV node, then to bundle of His and Purkinje fibres. It causes ventricular depolarization resulting in ventricular contraction.

8. T-wave is a broad upward wave which represents ventricular repolarization resulting in ventricular relaxation. 

9. Functions of ECG are mainly for diagnosis and also for prognosis. It is useful to detect abnormal functioning of heart as in coronary artery diseases, heart block, angina pectoris, tachycardia, ischemic heart disease, myocardial infarction, cardiac arrest, etc.

1. Normal activities of the heart are auto regulated. The specialized muscles help in this regulation. 

2. The heart is said to be myogenic due to this ability. 

3. In the medulla oblongata of brain, there is cardiovascular centre, 

4. From this centre, sympathetic and parasympathetic nerves innervate the sinoatrial node. 

5. Sympathetic nerves secrete adrenaline and it stimulates and increases the heartbeat. 

6. Parasympathetic nerves secrete acetylcholine and it decreases the heart rate. 

7. Rate of heartbeat is controlled in response to inputs from various receptors like proprio-receptors. 

8. These receptors monitor the position of limbs and muscles. There are chemoreceptors which monitor chemical change in blood and baroreceptors that monitor the stretching of main arteries and veins.

Chemical control on heart rate:

1. Hypoxia, acidosis, alkalosis cause decrease in cardiac activity. 

2. Hormones like epinephrine and nor epinephrine enhance the cardiac activity. 

3. Elevated blood level of K+ and Na+ decreases the cardiac activity.

1. Silent heart attack is a type of heart attack that lacks the general symptoms of classic heart attack like extreme chest pain, hypertension, shortness of breath, sweating and dizziness. 

2. Symptoms of silent heart attack are so mild that a person often confuses it for regular discomfort and thereby ignores it.

3. Men are more affected by silent heart attack than women.

1. Angiography is an X-ray imaging of the cardiac blood vessels to locate the position of blockages. 

2. Depending upon the degree of blockage, remedial procedures like angioplasty or by¬pass surgery are performed.

3. In angioplasty a stent is inserted at the site of blockage to restore the blood supply while in by-pass surgery, the atherosclerotic region is by-passed with part of vein or artery taken from any other suitable part of the body, like hands or legs.

(1) The working of heart or cardiac cycle is formed by atrial systole, ventricular systole and joint diastole. It takes place in 0.8 second. 

(2) During atrial systole from right atrium, the deoxygenated blood is poured into right ventricle through atrioventricular aperture.Similarly, from left atrium, the oxygenated blood enters the left ventricle through atrioventricular aperture. This entire atrial systole lasts for 0.1 second. 

(3) After auricular systole follows the ventricular systole. During ventricular systole, the deoxygenated blood from the right ventricle enters the pulmonary trunk, which carries blood to lungs for oxygenation. At the same time, the oxygenated blood from the left ventricle enters the aorta which is then supplied to all parts of the body. The ventricular systole lasts for 0.3 second. 

(4) Joint diastole or complete cardiac diastole is the phase taking place after the systole, when the entire heart undergoes relaxation, for 0.4 second. 

(5) During joint diastole, the right atrium receives deoxygenated blood from all parts of the body through superior vena cava, inferior vena cava and coronary sinus. The left atrium receives oxygenated blood from the lungs through two pairs of pulmonary veins.

Silent heart attack, also known as silent myocardial infarction, is a type of heart attack that lacks the general symptoms of classic heart attack like extreme chest pain, hypertension, shortness of breath, sweating and dizziness.

X-ray or imaging of the cardiac blood vessels to locate the position of blockages is called angiography.

The rate with which the heart beats per minute is called the heart rate.

The amount of blood thrown out of the ventricles during one minute is called cardiac output.

Study of blood vessels is called angiology.

Cardiac output is the volume of blood pumped out per min for a normal adult human being it is calculated as follows: Cardiac output = Heart rate × Stroke volume 

Given : Cardiac output = 5500 cm³ 

Pulse rate = Heart rate = 68 By using these values stroke volume of is calculated as follows: 

∴ Cardiac output = Heart rate × Stroke volume 

∴ Stroke volume = Cardiac output/Heart rate = 5500/68 = Approx. 80. 

∴ Stroke volume is 80 ml.

Removal of anther from a bisexual flower is called emasculation. It is used to avoid self pollination and is used in artificial hybridisation programme. It is done before the dehiscence of anther.

Blood Capillaries : Blood capillaries which are very thin narrow blood vessels that connect the arteries with the veins and distribute the blood to the body parts.

The amount of blood thrown out of the ventricles during one systole is called the stroke volume.

Blood vessel : These are tube like structures through which the blood flows in the body. There are three types of blood vessels in the human body.

d. (ii) and (iii)

(ii) protoplasts from cells of different species can be fused 

(iii) treatment of cells with cellulase and pectinase is mandatory 

Correct answer is (d) Amount of blood put out of the ventricles in one beat

Removal of anther from a bisexual flower is called emasculation. It is used to avoid self-pollination and is used in artificial hybridisation programme. It is done before the dehiscence of anther.

(i) Plant hybridization programme is often constrained by the availability of limited number of disease resistance genes that are present in various crop varieties or wild relatives.

(ii)  Several wild relatives of different cultivated species of plants have been shown to have certain resistant character but have very low yield.