Thoracic breathing is also known as forceful breathing which is controlled by cerebrum. Normal breathing is also called abdominal breathing which is under the control of medulla.

Severe acute respiratory syndrome (SARS) is a highly contagious viral disease caused by a novel coronavirus, known as the SARS-associate coronavirus (SARS-CoV). Coronaviruses are positive-strand RNA viruses.

Both parietal pleura and visceral pleura are composed of simple squamous epithelium. These two layers surround the lungs and has a cavity present in between them known as the pleural cavity.

Coryza(common cold) is caused by the rhinovirus in adults.

In the liver the following are carried out: 
i. Hemoglobin of worn out erythrocytes breaks down into bile pigments 
ii. Excess quantities of carbohydrates are converted to glycogen known as glycogenesis 
iii. The reversal of glycogen into glucose known as glycogenolysis

During forced or difficult breathing expiration becomes an active process. Contraction of the abdominal muscles pushes the viscera and the diaphragm upwards, reducing the vertical diameter. Contraction of the internal intercostals depresses the ribs and reduces the thoracic cavity.

Heart failure is sometimes referred to as congestive heart failure as congestion of the lungs is one of the main symptoms of this disease.

There are three germ layers present : Ectoderm , mesoderm and endoderm. The connective and muscular tissue are of mesodermal origin while the nervous tissue is of ectodermal origin. Hence ,the smooth muscles of iris are of ectodermal origin.

The iris contains two types of smooth muscles : circular muscles (sphincters) and radial muscles ( dilators) of ectodermal origin. Both these sets of muscles are under the control of the autonomic nervous system. Sympathetic stimulation causes the radial muscles to contract and the pupil to dilate. Parasympathetic stimulation causes the circular muscles to contract and the pupil to constrict.

Semilunar valves help in preventing the flow of the blood back from aorta into the ventricles.

Time taken by ball to reach maximum height 
_{V = u - gt} 
At maximum height v=0 
Or T=u/g 
Let speed = 19.6 m/s time to reach max height = 19.6/9.8 = 2sec
As we know the ball will be back in the ground after 2 sec
Time of ascent = time of descent
at this speed the ball will be back to ground by the time next ball reaches the top. So only two ball will be in air. To have more than two balls speed should be greater than 19.6 m/s.

Given, 

Height attained by body after projecting vertically upward = Radius of earth 

We know 

Power = F.v = Fv cos ө

Here, direction of F is vertically downward 

Direction of velocity is upward when it is going up with decreasing its magnitude and downward when it is coming down with increasing its magnitude. 
So, just before hitting θ is zero and both F and v are maximum.

Fluorine is the only element that reacts with Xe because of its highest electronegative. It is the only element which is strong enough to pull electrons out of the stable xenon.

Na₂SO₃ reacts with dilute H₂SO₄ to give SO₂ gas which reacts with K₂Cr₂O₇ + dil. H₂SO₄ to give a green solution due to the formation of Cr₂(SO₄)₃. As whole of SO₂ gas reacts away, on passing the resulting gas through lime water, it remains clear.