Question 1

Question 1Why is a respiratory system necessary?

Accepted Answer

Respiration is a vital process in all living organisms.Respiratory system is necessary because:Respiration is a vital process in all living organisms. Every cell of a plant, an animal or of human body requires energy for various activities. Respiratory system provides this energy by the oxidation of glucose using oxygen.Respiratory system helps in breathing through which oxygen from the air is pulled into the lungs and the air containing carbon dioxide is forced out of the lungs.Respiratory system helps in gaseous transport. Oxygen of the inhaled air is absorbed by the blood in the lungs where it combines with the haemoglobin present in RBCs. The Oxygen is carried from lungs to the body tissues where the Oxygen is utilised and Carbon dioxide is released.

Question 2

Question 2What factors are most likely to affect the breathing rate?

Accepted Answer

Some of the factors that affect the breathing rate are:While exercising or doing intense physical activity, the body requires more energy due to which the demand of oxygen increases. This increases the rate of breathing of the person.While sleeping and resting, the breathing rate decreases as the body requires less energy.Allergic reactions increase the rate of breathing as allergic reactions narrow the nasal passage leading to a demand for more oxygen.Stress and anxiety increases the breathing rate as the stress hormones trigger the body's fight or flight response.

Question 3

Question 3What happens to the energy liberated during respiration?

Accepted Answer

The energy liberated during respiration is not all in the form of heat but a large part of it is converted into chemical energy in the form of ATP (Adenosine Triphosphate). This energy is utilised by the body cells for a vast variety of activities like:Digestion of food.Production of enzymes.Contraction of muscles for movement.Conduction of electrical impulse in a nerve cell.Production of new cells by cell division.Keeping the body warm in warm-blooded animals.

Question 4

Question 4What do you understand by inhalation and exhalation? How are they different from each other?

Accepted Answer

Inhalation is the physical process by which the air containing oxygen is drawn into the lungs.Exhalation is the physical process by which the air containing carbon dioxide is forced out from the lungs.Differences between Inhalation and Exhalation are:InhalationExhalationRibs move upwards and outwards.Ribs move downwards and inwards.Diaphragm is pushed downwards and flattens.Diaphragm moves upwards and becomes dome-shaped.Volume of chest cavity increases.Volume of chest cavity decreases.Lungs expand, air pressure becomes low.Size of the lungs reduces, air pressure becomes high.Atmospheric air at a higher pressure rushes into lungs.Air rushes out of the lungs as atmospheric air pressure is lower.

Question 5

Question 5What do you understand by the term respiratory diseases? Name any three common respiratory diseases.

Accepted Answer

The diseases that affect the respiratory organs of the body making respiration difficult are termed as respiratory diseases.The three common respiratory diseases are:BronchitisAsthmaPneumonia

Question 6

Question 6State the cause and treatment for the following diseases:TuberculosisPneumoniaBronchitis

Accepted Answer

TuberculosisCause — This respiratory infection is caused by bacteria that can spread by air, dust or sputum.Treatment — BCG vaccine, antibiotic Streptomycin.PneumoniaCause — This respiratory disease is mainly caused by bacteria inhaled through air or by contact.Treatment — Antibiotic - Penicillin.BronchitisCause — This respiratory infection is mainly caused by a virus. Air pollution and smoking can also cause bronchitis.Treatment — Drinking plenty of fluids, following a well balanced diet, frequent hand washing and adequate rest can prevent and improve bronchitis.

Question 7

Question 8The diagram given alongside is an experimental set up mimicking a certain process occurring in living beings. Study the figure and answer the following questions :(i) Name the process and define it.(ii) What are the two phases of the above mentioned process shown as (A) and (B) ?(iii) Name the particular organs of the body shown in the figure with :(a) Bell jar (b) Balloons (c) Rubber sheet(iv) How do these phases (A) and (B) differ with respect to the position of ribs ?(v)	Does the breathing rate of a young boy and an old person differ ? Explain.

Accepted Answer

(i) The given diagram shows an experimental set up to demonstrate the process of Breathing.Breathing is the process during which the air containing oxygen is drawn into the lungs and the air containing carbon dioxide is forced out from the lungs. It is a physical process.(ii) Phase (A) shows Inspiration, and Phase (B) shows Expiration.(iii) The particular organs of the body shown in the figure are:     (a) Bell jar — Chest cavity     (b) Balloons — Lungs     (c) Rubber sheet — Diaphragm(iv) During Inspiration [Phase (A)], ribs move upwards and outwards while during Expiration [Phase (B)] ribs move downwards and inwards.(v) Yes, the breathing rate of a young boy and an old person typically differ. Young children have a higher breathing rate than adults, due to their higher metabolic needs and smaller lung capacity relative to their body size. In contrast, older people breathe more slowly as their metabolic rate is lower and lung function may decline with age.

Question 8

Question 9The diagram given alongside shows the "Human Respiratory System". Study the same and answer the following questions :(i)	Label the guidelines 1 to 4.(ii) Define the structure shown as part 2.(iii) Name the basic structural and functional unit of part 3.(iv) Write one specific structural feature of the inner lining of part 1.(v)	What is the muscular sheet on which part 3 rests ?

Accepted Answer

(i) The guidelines 1 to 4 show:TracheaLarynxLungBronchus(ii) At the entrance of the trachea, there is a voice box called larynx. It contains two ligamentous folds called 'vocal cords'. Air expelled forcibly through the vocal cords vibrates them, to produce sound.(iii) Alveoli is the basic structural and functional unit of part 3, i.e., lungs.(iv) The inner linings of the trachea, bronchi and bronchioles have ciliated epithelium. The continuous movement of the cilia pushes out the unwanted particles that may be present in the inhaled air.(v) Diaphragm is the muscular sheet upon which the lungs rest.

Question 9

Question 3Write one important role of each of the following .EpiglottisLarynxAlveolusPleuraNasal chamber

Accepted Answer

Epiglottis guards the front opening (glottis) of the wind pipe. It closes the wind pipe at the time of swallowing of food, and hence prevents any wrongful entry of food into the wind pipe.Larynx contains two ligamentous folds called 'vocal cords'. Air expelled forcibly through the vocal cords vibrates them to produce sound.Alveoli are richly supplied with blood capillaries covering their walls. The walls of the alveoli are extremely thin and moist for allowing faster diffusion of gases.Pleura protects the lungs. The fluid filled in the space between the outer and inner pleura acts as a shock absorber for the lungs.The lining of the nasal chamber has mucous (a sticky fluid) which traps germs and dust, so they don't enter our body.

Question 10

Question 6Correct the following statements by changing the first/ last word only :BCG is a kind of vaccine used to prevent Pneumonia.Streptomycin is a kind of vaccine.Breathing is a bio-chemical process.The amount of oxygen in expired air is 21%.The front opening of the trachea is guarded by a muscular flap called diaphragm.

Accepted Answer

BCG is a kind of vaccine used to prevent Tuberculosis.Streptomycin is a kind of antibiotic.Respiration is a bio-chemical process.The amount of oxygen in expired air is 16%.The front opening of the trachea is guarded by a muscular flap called epiglottis.

Respiratory System

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