The document contains multiple choice questions about respiratory system. It tests knowledge about various processes like gaseous exchange, parts of respiratory tract in humans and plants, diseases of respiratory system like pneumonia, bronchitis, emphysema etc. It also contains definitions of various terms and structures related to respiration like stomata, lenticels, nicotine, diaphragm etc. Short questions at the end ask to define processes like cellular respiration, describe parts of respiratory tract and their functions, and differences between related terms.

1. Exercise No1
Multiple Choices
1. The process of gaseous exchange involves.
a) Breakdown of C-H bonds to yield energy
b) Physical movements that take air in and out of the body
c) Getting oxygen from the air and removing carbon dioxide
d) Transport of oxygen by the blood to different parts of the body
2. Most of the gaseous exchange in a leaf occurs through;
a) Stomata b) General surface c) Cuticle d) Lenticels
3. How many bronchi are there in the air passageway?
a) One b) Two c) Many d) None
4. Where does the gaseous exchange occur in humans?
a) Pharynx b) Trachea c) Bronchi d) Alveoli
5. Which structure activity help in taking air the air out of lungs?
a) Nasal cavity b) Bronchus c) Bronchiole d) Diaphragm
6. The primary chemical stimulus for breathing is the concentration of;
a) Carbon dioxide in the blood b) Oxygen in blood
c) Carbon dioxide in muscles d) Oxygen in muscles
7. Point out the FALSE statement about respiration
a) Gases can easily pass through the walls of the alveoli
b) Gas can exchange in lungs is very efficient because lungs provide large surface area
c) In emphysema the walls of alveoli break and there is more surface area
d) Dust particles can damage the lung by irritating the inner alveoli surface
8. A disease involving breakdown of air sacs of the lungs is;
a) Pneumonia b) Bronchitis c) Asthma d) Emphysema
9. Which process does NOT occur in the nasal cavity?
a) Trapping of large dust particles b) Humidification of the inhaled air
c) Warming of the inhaled air d) Exchange of gases
10. What type of vessels surrounded the alveoli?
a) Artery b) Arteriole c) Capillary d) Vein

2. Exercise
Multiple Choices
1. Which of the following describes a correct order of structure in the respiratory passage way
in humans?
a) Pharynx, trachea, larynx, bronchi, bronchioles,
b) Larynx, pharynx, trachea, bronchioles, bronchi,
c) Trachea, pharynx, larynx, bronchi, bronchioles,
d) Pharynx, larynx, trachea, bronchi, bronchioles
2. The structure which close off the larynx when food is being swallowed is the;
a) Glottis b) Epiglottis c) internal nares d) vocal cords
3. Gaseous exchange in the lungs happens by the process of?
a) Osmosis b) Diffusion c) Exocytosis d) Active transport
4. What is the scientific name of vocal cord?
a) Pharynx b) Trachea c) larynx d) bronchus
5. What is the correct percentage of oxygen, carbon di oxide and nitrogen in exhaled air (in the
given Table)?
b) O2 16%, CO2 4%, and Nitrogen 78%
6. Lowering the diaphragm results in the;
a) Inspiration b) Expiration c) Excretion d) Digestion
7. For a respiratory surface to function in the exchange of gases with in an animal it must:
a) it must be thin and soft b) Have a high no of blood vessals
c) Have mucous or a moist covering d) All of these
8. Smoking has been shown to cause:
a) Lung cancer b) Emphysema c) Asthma d) All of these
9. Which chemical in cigarette smoke causes staining of teeth and fingers?
a) Tar b) Nicotine c) Polonium d) Carbon mono oxide

3. SHORT Questions
Q1: - Define cellular Respiration.
Ans: - Cellular Respiration is the process in which the C—H bond of food is broken
down by oxidation reduction reactions and energy is obtained in the form of ATP.
Q2: - Define Bronchitis and write its types.
Ans: - Bronchitis is the inflammation of bronchi and bronchioles. It results in excessive
secretion of mucous into the tubes, leading to the swelling of tubular wall and narrowing
of tubes. Usually it is caused by viruses, bacteria or chemicals.
It has twotypes
Acute bronchitis: - it last usually for twoweeks and patient recovers with out any
permanent damage in the bronchi or bronchioles.
Chronic bronchitis: - It usually last for months and even years and mostly it leaves a
permanent damage in the bronchi and bronchioles.
Q3: - What are stomata write their role.
Ans: - Stomata are small pores present on the epidermis of f leaves and small stem and
they allow gaseous exchange in leaves and young stem.
Q4: - What are lenticels write their role.
Ans: - In woody stem and mature roots the entire surface is covered by bark and there
are certain pores in the bark which allow air to pass through the and that are known as
lenticels.
Q5: - What is Nicotine?
Ans: -Nicotine is a powerful poison and was widely used as insecticide in the past when
inhaled through tobacco smoking, it reaches our circulatory system and not only harden
the arteries but also damage the brain tissues.
Q6: - What is the difference between breathing and respiration?
Ans: - Respiration is biochemical process in which glucose molecule is broken down
and energy is obtained where as breathing is a mechanical process consists of inhalation
and exhalation.
Q7: - what is inflammation?
Ans: - Inflammation is an important defensive mechanism of the body for dilution,
neutralizing or killing the causative agent of a disease. It is characterized by swelling,
Red colour, pain, heat and loss of function of a particular part of the body.
Q8: - Where does gaseous exchange in animals? & how blood is oxygenated?
Ans: - Gaseous exchange in animals takes place in alveoli. There are capillaries present
around each alveolar sac which have de-oxygenated blood. The oxygen from alveolar sac
is absorbed in the blood (hemoglobin makes bond with oxygen) and the CO2 due to its
more concentration is removed from blood and in such way blood is oxygenated and
gaseous exchange takes place.
Q9: - What is the difference between bronchi and bronchioles?
Ans: - Trachea divides into twobranches (tubes) known as bronchi and the bronchi
further divides into more and very fine tubes which are known as bronchioles.
Q10: - What is diaphragm?
Ans: - Diaphragm is a dome shapes, thick muscular sheet present below the lungs and
it helps in breathing. Also it separates the chest cavity from abdominal cavity.
Q11: - What are pleural membranes?

4. Ans: - Each lung is covered by a n outer and inner membrane which are known as
pleural membrane and between these two membranes there is a fluid which help in
expansion and contraction of lungs.
Q12: - What Do you know about gaseous exchange in plants?
Ans: - Gaseous Exchange in Plants
Plants gets their energy from respiration. Plants have no special organ or system fro exchange
of gases. The gaseous exchange in plants occurs in cells, of every part of the plant i.e. roots,
stems and leaves etc according to their energy demand. The conducting system(xylem and
phloem) of plants transports water and nutrients but plays no role in the transport of gases.
The air spaces present between the cells of parenchyma of leaves, stemand roots are involved
in the gaseous exchange.
Gaseous Exchange in Leaves and Young Stems
In the leaves and young stems, gaseous exchange occurs through stomata. Some gaseous
exchange also occurs through cuticle.
Gaseous Exchange in Woody Stems and Roots
In woody stem and roots, there are present dead cells beneath the epidermis which form cork
tissue. Later on, this tissue becomes porous. The pores are called lenticels. These are involved
in gaseous exchange.
Gaseous Exchange in Leaves
The aquatic parts obtain oxygen for their respiration by diffusion from the dissolved oxygen in
water. Whereas the land plants get their oxygen from air directly through their stomata which
are more abundant on the lower surface than the upper surface of leaves.
Gaseous Exchange in Roots
The roots get their oxygen for gaseous exchange through diffusion from the air existing in the
space between soil particles.
Q13: What do you mean by Breathing?
Ans: - It is defined as the process through which animals take air in their bodies to get oxygen
from it then given out the air for getting rid of CO2. Breathing is also called as ventilation. It has
two parts:
Inhalation:
The passage of air into lungs is known as inhalation.
Exhalation:
The passage of air out of the lungs to expel carbon dioxide is known as exhalation.
The above two processes are collectively called breathing.
Control of Breathing: The control of breathing is controlled by the respiratory center in the
brain.
Concentration of carbon dioxide: The respiratory center is sensitive to the concentration of
CO2in blood. Respiratory center sensitive to sensitive to carbon dioxide: when we do exercise
or some hard job our muscles carry out cellular respiration at greater rate which result in the
production of more CO2which released in the blood. It results in the production of more CO2.
This greater than normal concentration of CO2 stimulates the respiratory center in the brain.
The respiratory center send messages to brain to carry rib muscles out and cellular respiration
to increase the rate of breathing so that the excess carbon dioxide present in the blood can be
removed out of the body.
Q14: - What do you know about Respiration in plants?

5. Ans: - Process of Respiration in Plants
The respiration in plants continues day and night. In this process, the oxygen from the airspaces
in the leaves and stems is diffused into tissues and cells after getting dissolved in the filmof
water which is present over the cells. In the cells this oxygen oxidizes the carbohydrates and
other organic compounds into carbon dioxide and water to produce energy. Some of the water
(vapours) comes in the airspaces from where they diffuse out to the atmosphere through
lenticels and stomata. The elimination of carbon dioxide is more evident from the parts without
chlorophyll like growing seeds and buds. The water produced in this process becomes a part of
the already present water in the body of plants. The various chemical reactions of respiration
are controlled by the specific enzymes. This process occurs at a faster rate in the parts of the
plant having rapid growth like growing seeds, buds, apical meristem of roots and shoots,
because these parts require more energy to accomplish the growth process.
Q15: - Discus the relationship between respiration and photosynthesis?
Ans: - Relationship between Respiration and Photosynthesis
The gaseous exchange in plant is not very evident during the day time as the products of
respiration i.e. carbon dioxide and water are used in the process of photosynthesis. In the
bright sunshine, because of high rate of photosynthesis the carbon dioxide produced in
respiration falls short and therefore, some carbon dioxide has to be taken into the plant from
outside for photosynthesis.
In the day time the plants therefore, take in carbon dioxide and expel out oxygen. The process
of photosynthesis occurs in chloroplasts whereas the process of respiration takes place in
cytoplasm and mitochondria.
Q16: - What do you know about gaseous exchange in Animals?
Ans: - Gaseous Exchange in Animals
the gaseous exchange in different animals takes place by different methods and organs. In
unicellular aquatic animals like amoeba, the dissolved oxygen in water diffuses directly through
their cell surface into the interior of the animal and the carbon dioxide similarly diffuses out
from their bodies into the external water. This is the simplest way of gaseous exchange and it
can occur only in small animals with a diameter of less than one millimeter.
During evolution, as the animals became complex and complex and grew in their size, their skin
or external body surface become impervious to water. Thus the gaseous exchange became
impossible through diffusion. In large animals certain organs were developed for exchange of
gases e.g. the moist vascular skin, gills, lungs and tracheoles. The large animals have developed
blood vascular systemwhich transports oxygen from the respiratory surface to the deep cells
and tissues in all parts of the body. The blood in all animals has some respiratory pigments like
haemoglobin which carry large amount of oxygen efficiently from respiratory surface to the
interior cells.
Human Respiration
Q17: - Brieflydescribe the parts of Respiratory tract and their function?
Ans: - The Air Pathway:
1. Nasal Cavity - Warms moistens,&filtersairasit isinhaled.
2. Pharynx (throat) – Passagewaythatleadstotrachea.
3. Trachea (windpipe) –Cartilage keepsthe tracheaopen.The tracheaislinedwithcilia,whichfiltersthe
air before itreachesthe lungs.
4. Bronchi (left&right) – These branchesleadtothe lungs.

6. 5. Bronchioles - These small branchesleadtothe airsacs.
6. Alveoli - The functional unitof the respiratorysystem.Thisiswhere oxygenandcarbondioxideare
exchanged.O2entersthe blood;CO2is removedfromthe blood
Q18: - Describe the parts of Respiratory tract and theirstructure and function?
Ans: -
Human Respiratory System
In humans, there is very efficient respiratory system. It consists of certain organs which are
called respiratory organs these include nose, pharynx, larynx, trachea, bronchi and bronchioles.
Nose
The air enters through the external nostrils into the nasal cavity. This is lined with mucous
secreting epithelium and ciliated epithelium. The nostrils are lined with hairs, The beating of
cilia creates a current in the mucus that carries the trapped particles towards the back of the
nasal cavity. From here the mucus drips into the throat and is swallowed or removed out of the
body. Mucus keeps the nasal cavities moist. Bones of the nose warm up the air. Mucus
moistens the air. Hair filter the air and stop the dust particles bacteria and any other foreign
substance from going to next part of respiratory system. In this way air is purified and is then
pushed into the pharynx.
A number of cavities called sinuses open into the nasal cavity. The sinuses are lined with mucus
secreting epithelium. The opening of sinuses into the nasal cavity is very narrow. If these
openings are closed due to cold or inflammation, the sinuses get filled up with mucus this
results in headache and changed voice.
Pharynx
The nasal cavity opens into the pharynx (throat) through two small apertures which are called
internal nares or internal nostrils. The pharynx is muscular passage which extends from behind
the nasal cavities to the opening of esophagus and larynx. The air goes from the pharynx into
the larynx.
Larynx
The upper most part of the wind pipe (trachea) is called the larynx. The larynx is a cartilaginous
box. Two fibrous bands called vocal cords are located in this box. These vibrate to produce
sound. Larynx is, also called sound box or voice box. The air enters the larynx through a small
aperture called glottis which is guarded by a muscular flap called epiglottis which fits into this
opening while the food is being swallowed into the esophagus. It prevents the food from
entering into the trachea and choking it. During breathing epiglottis keeps the glottis open so
that air goes to trachea.
Trachea
The air tube (wind pipe) is known as trachea. It is about 12 cm long and lies in front of the
esophagus. It has incomplete C shaped cartilaginous rings which are regularly placed in its wall
and all along its length. These rings prevent the collapsing of the tube nd thus keep the air
passage wide open all the time. Trachea is also lined with ciliated mucous epithelium. Any
foreign particles present in the inhaling air get trapped in the mucous that is moved out of the
trachea by breathing of the cilia in the upward direction. In trachea air is further cleansed and
filtered and then moved towards the lungs.
Bronchi
Bronchi: On entering the chest cavity the trachea divides into two smaller tubes called bronchi
(single bronchus).

7. Structure: Bronchi are similar in structure to the trachea but are smaller in diameter and the
bronchi also have cartilaginous sings plates in their walls.
Division of bronchi: Each bronchus enters into the lungs of its side and divides into smaller
branches Each bronchus enters into the lungs of its own side. The right bronchus divides into
three secondary bronchi and the left bronchus divides into two secondary bronchi which serve
the 3 right and 2 left lobes of the lungs respectively.
Function: Bronchi is lined with ciliated and glandular cells.
Function of glandular cells: These cells secrets mucous which moisten the air and also trap any
fine particles of dust or bacteria that have escaped from the nasal cavity.
Function of cilia: The cilia beat with and upward motion so that the froegin particles along the
mucous are sent to the oral cavity from where it may be the either swallowed are coughed out.
Bronchioles
the secondary bronchi further divide into very fine branches until they end in thousands of
passage ways called respiratory bronchioles. The bronchioles have not cartilaginous plates in
their walls. They have smooth muscle and elastic fibers.
Alveoli
The walls of the respiratory bronchioles have clusters of tiny branches(like bunches of grapes)
that along with the respiratory bronchioles re the sites of gaseous exchange, these pouches or
air sacs are called alveoli (singular: alveolus). The alveoli are enormous in number. Each lung
has about three hundred million alveoli.
Pulmonary artery brings deoxygenated blood from the heart into the lung. Here, it divides and
re-divides until it forms a network of fine capillaries over the wall of each alveolus. The walls of
alveoli are very thin (1/1000 mm thick) and moist. Thus, alveoli are efficient site for gaseous
exchange.
The Lungs
There is a pair of lungs present in the chest in man. Actually, the masses of alveoli constitute
lungs and their lobes. The lungs re protected by the chest box from sides and by a doem shaped
muscular diaphragm from below. Chest box or ribcage is made up of ribs. Between the ribs,
there are present inter-costal muscles. The diaphragm is a muscular sheet which partitions the
chest and abdomen.
The two lungs re covered by a double layered membrane called pleural membrane. There is a
thin film of fluid in between the two layers. This watery fluid makes the movements of the
lungs (expansion and contraction) easy. It also protects the lungs from external injuries.
(Diagram)
Q19: - what do you know about chest walls and diaphragm?
Ans: - Chest wall formation: The dorsal portion of chest wall is made up of muscles called
intercostal muscles.
Diaphragm: A thick muscular, dome shape structure present below the lungs is known as
diaphragm and it help in breathing.
Q20: - How many lobes are there in lungs?
Ans: - Lobes of lungs: The left lung is slightly smaller and has two lobes and the right lung is
bigger with three lobes.
Q21: - What do you know abut the blood supply of lungs?

8. Ans: - Blood vessels of lungs: The blood vessels that supply blood to lungs are pulmonary
arteries and veins.
Q22: - What do you know about membranes of lungs?
Ans: - The lung consist of two membranes known as
1. inner pleural membrane
2. Outer pleural membrane
Fluid between lungs: The membrane encloses a fluid which provides lubrication for free
expanding and contracting of lungs this fluid is known as surfactant.
Q23: - What do you know about Mechanism of Breathing?
Ans: - Mechanism of Breathing
Breathing occurs in two phases:
1. Inspiration
2. Expiration
1. Inspiration
1. During inspiration, the dome-shaped diaphragm contracts and becomes flat some what and
thereby lowering the floor of the thoracic cavity.
2. The external inter-costal muscles contract raising the ribcage. A combined action of these
two events expands the thoracic cavity, which in turn expands the lungs.
3. The air pressure within the lungs decreases.
4. Thus air from the environment outside the body is pulled into the lungs to equalize the
pressure of both sides.
2. Expiration
1. The diaphragm relaxes and assumes dome like shape. During expiration, the external inter-
costal muscles relax and the internal inter-costal muscles contract as a result of which ribcage
drops.
2. The combined action of these two event decreases the volume of the thoracic cavity which in
turn decreases volume of lungs.
3. The air pressure with in the lungs increases.
4. The air is thus forced out of the lungs.
Q24: - What do you know about Respiratory disorders?
Respiratory Disorders
Describe different types of respiratory disoroders in man.
Ans. There are a number of respiratory disorders which affect people. The high
percentage is due to more concentration of air pollutants both in of respiratory disorders
in Pakistan urban and rural atmosphere.
Some of the important respiratory disorders are:
Bronchitis: - It is the inflammation of bronchi or bronchioles. It results in excessive
secretion of mucus into the tubes, leading to the swelling of tubular walls and narrowing
of the tubes.
Causes: - It is caused by virus, bacteria or chemical irritants.
Types: - there are two types of bronchitis

9. 1. Acute Bronchitis: - It last for a short period (two to three weeks) and patient
recover mostly with out any permanent damage in respiratory tract.
2. Chronic bronchitis: - It last usually for a long period (months and even years) and
patient recovers but mostly with a permanent damage in respiratory tract.
Symptoms
Symptoms ofbronchitis include:
i. Cough
ii. Mild wheezing
iii. Fever
iv. Chills
v. Shortness: of breath (especially when doing hard job)
Age limit
The majority of people diagnosed with chronic bronchitis are 45years of age or older.
Emphysema
Introduction
It is the destruction of the walls of the alveoli
Explanation
It results in larger sacs but with less surface area for gaseous exchange. As lung tissue breaks
down, the lungs do not come back to their original shape after exhalation so air cannot be pushed
out and is trapped in the lungs.
Symptoms:
It includes:
i. Shortness of breadth
ii. Fatigue
iii. Recurrent respiratory infections
iv. Weight loss
Effects
The level of oxygen of blood may get so low that it causes serious complications. By the time the
symptoms of emphysema appear, the patient has usually lost 50% to 70% of his/ her lung tissue.
iii. Pneumonia
Introduction:
Pneumonia is a viral, bacterial, or fungal infection of the lungs in which bronchi and alveoli fi ll
with a discharge, such as pus and fluid.
Double pneumonia:
Infection which affects both lungs, it is called double pneumonia.
Types: -
Lobular Pneumonia: - In this case only a small part of the lobe is infected.
Lobar pneumonia: - In this case whole lobe of the lung is infected.
Causes:
The most common cause of pneumonia is a bacterium “Streptococcus
pneumoniae.
Some Viral (influenza virus) and fungal infections may also lead to pneumonia.
Explanation:

10. When the causative organisms enter the alveoli, they break the lung tissues and the area
becomes filled with fluid and pus.
Symptoms:
It includes a cold that is followed by a high fever, shivering, and a cough with
sputum production. Patient may becomeshort ofbreath.
Effects:
The patient’s skin colour may change and become dusky or purplish. It is due to
poor oxygenation of blood.
Treatment:
Vaccines are available to prevent caused by S. Pneumonia. Antibiotics are used in the
treatment of this disease.
Asthma
Introduction:
It is a form of allergy, in which there is inflammation of the bronchi, more mucous
production and narrowing of the airways.
Explanation:
In asthma patients, the bronchi and bronchioles become sensitive to different
allergens (allergy causing factors) e.g. dust, smoke, perfumes etc. When exposed to
any of such allergens, the sensitive airways show immediate and excessive response
of constriction. In this condition, the patient feels difficulty in breathing.
Symptoms:
It varies from person to person. It includes:
i. Shortness of breath
ii. Wheezing
iii. Cough
iv. Chest tightness
Treatment:
The medicine in the form of inhalers with ability to dilate the bronchi and bronchioles are
used in the treatment of asthma.
Lung Cancer:
Introduction
It is a disease of uncontrolled cell divisions in the tissue of the lungs.
Explanation:
In lung cancer, cells continue to divide without any control and form tumors. The cellular
growth may also invade adjacent tissue beyond the lungs.
Causes
The main causes are:
i) Carcinogens (such as those in cigarette smoke)
ii) Ionizing radiation and
(iii) Viral infection
Main cause: Smoking is the main cause of lung cancer.
Symptoms:
The most common symptoms are:
1. Shortness of breath
2. Coughing (including coughing up blood)

11. 3. Weight loss
Q25: - How many carcinogen are present in cigarette?
Ans: - Cigarette smoke contains over 50 known carcinogens.
Q26: - Is there any effect of cigarette smoke upon non smokers?
Ans: - Lung cancer in non- smokers
The risk of lung cancer is significantly lower in non-smokers.
Passive smoking (the inhalation of smoke from another's smoking) is also a cause of lung cancer
The smoke from the burning end of a cigarette is more dangerous than the smoke from the filter end.
Prevention
Eliminating tobacco smoking is a primary goal in the prevention of lung cancer.
The world Health organization has called for governments to stop tobacco advertising to prevent young
people from taking up smoking.
If a person stops smoking the chance to develop cancer decreases as damage to the lungs is repaired
and contaminant particles are gradually removed.
Effects
Lung cancer is the most common cause of cancer-related deaths and is responsible for more than1.3
million deaths worldwide annually.
Q.27 Describe bad effects of smoking.
Ans. Introduction:
Smoking is harmful due to the chemicals in cigarettes and smoke.
Number of chemicals in cigarette smoke
Tobacco smoke contains over 4000 different chemicals, out of which at least 50 are
carcinogens and many are poisonous.
Diseases due to smoking.
Smoking not only produced lung cancer but also produces a number of life threatening
Diseases like:
Cancers in
i. Kidneys
ii. Oral cavity
iii. Larynx
iv. Breast
v. Bladder and
vi. Pancreas etc.
Emphysema and other respiratory disorders
Many chemicals in tobacco smoke damage the air passageway, which leads to Emphysema and
other respiratory disorders.
Other effects of smoking
(a) Reduction in the oxygen carrying capacity
It has effects on the circulatory system the carbon monoxide present in tobacco
smoke lessens the oxygen carrying capacity of hemoglobin.
(b) Increase in the production of platelets
Many other chemicals in smoke increase the production of blood platelets. When
platelets are more than the normal numbers, they make the blood viscous and it
can lead to arteriosclerosis.
(c) Risk of tuberculosis and pneumonia

12. Smokers are at greater risk of developing infections, particularly the lungs like
tuberculosis by two to four times, and of pneumonia by four times.
(d) Weakening and staining the teeth
Smoking is responsible for weakening and staining the teeth. Tooth loss is 2 to 3
times higher in smokers than in non-smokers.
(e) Effect on social life
Smoking also affects the social life of a person. Smokers may face social unacceptance
because other people may not want to be exposed to other's smoke.
(f) Increase in the rate of heart diseases and cancer in non- smokers Non-smokers
Who are exposed to second- hand smoke al home or work' bean disease risk by 25-30
and their lung cancer risk by 20-30
Q28. What do you know about Nicotine?
Ans. Nicotine is a powerful poison and was widely used as an insecticide in the past. When
inhaled through tobacco smoking. It reaches our circulatory system and not only hardens
the walls of the arteries but also damages the brain tissues.
Q29. When the "World No Tobacco Day" is celebrated"?
Ans. It is celebrated on the 31't of May every year.
Q30: - What do you mean by pyogenic bacteria?
Ans: - Pus producing bacteria are known as pyogenic bacteria i.e. S.pneumonie
Q31:- what are the bad effects of smoking?
Ans: - Bad Effects of Smoking on Health
Smoking is injurious to human health. The smoke contains many chemical and gases. Dried
tobacco leaves are used in cigarettes. The tobacco on burning produces a number of dangerous
and toxic compounds.
Chemicals Present in Cigarette Smoke and Their Harmful Effects
(a) Nicotine
1. Man is addicted to cigarette damages brain tissues.
2. Causes blood to clot more easily.
3. Harden walls of arteries.
(b) Tar
1. Kill cells in air passages and in lungs.
2. Increases production of mucous and phlegm in lungs.
3. Causes lung cancer.
(c) Carbon Monoxide
prevents red blood cells from combining with and transporting oxygen around the body.
(d) Carcinogens
promote the growth of cancerous cells in the body.
(e) Irritants
1. Irritate air passages and air sacs in the lungs.
2. Kill cells at the surface of air passages.
3. Causes smoker’s cough and lung cancer.