Biology for 9 & 10
Chapter- 7
Exchange of Gases
Q. 1. What is cellular respiration?
Ans: A series of metabolic process that take place within a cell in which biochemical energy is harvested from organic substance and stored as energy carries ATP for use in energy-requiring activities of the cell is called cellular respiration.
Q.2. What is the function of Pleura?
The inner surface of the lung is covered by a double layered membrane which is named as pleura. Space between the two layers contains one type of fluid. Pleura saves lungs from friction as the lungs rub against the thorax during breathing.
Q.3. What is Bronchitis?
Acute and chronic inflammation of the inner lining of any partof the bronchi and bronchial tube is called bronchitis. The disease is caused by bacterial infection. Living in the unhealthy conditions, inhaling dust, pollution air, smoking cigarettes and cold are some of the reasons that may cause bronchitis. Once attacked by bronchitis there is every possibility of frequent attack.
Q.4. What is the function of the Diaphragm?
Diaphragm is muscular sheet which separate the thoracic cavity increases. When diaphraph expands it move upward. When thoracic cavity contracts the chest returns to its normal position. Diaphragm plays an important role in respiration.
Q.5. What are the causes of Pneumonia?
Pneumonia is a lung disease. Excessive cold may cause this disease. Excessive cold after bronchitis may lead to pneumonia. It is a dangerous disease for children and elderly people. Pneumonia is caused by Pneumococcus bacteria.
Q.6. Write down the symptoms of tuberculosis.
Multiple-choice questions
1. Which is the cause of tuberculosis?
A. Virus
B. Bacteria
C. Fungi
D. Protozoa
2. Gaseous exchange in plants occur through
i) stomata
ii) lenticels
iii) root hair
Which one is correct?
A. i & ii
B. i & iii
C. ii & iii
D. i , ii & iii
Answer the questions 3 and 4.
Rita went to the doctor with a complaint of weakness. Doctor informed her that she has a deficiency of a particular blood cell. To meet this insufficiency he advised her to take more nutritious food and vegetables.
3. Which one is deficiency in Rita's blood?
A. Red blood corpuscles
B. Platelet
C. White blood corpuscles
D. Plasma
4. That Particular cell-
i) is a compound of iron
ii) reacts with oxygen
iii) contains CO2
Which one is correct?
A. i & ii
B. i & iii
C. ii & iii
D. i, ii & iii
Creative questions
1. A. Which cell carries oxygen in the blood?
Ans: Red blood corpuscles carry oxygen.
B. What is the trachea?
Ans: Trachea is a part of human respiratory system. It is a long tube which lies in front of esophagus. It starts below larynx and devides into two and enters the lungs.
C. Explain the process meant by P.
Ans: In the figure P through nasal passage O2 is inspired in lungs and CO2 is respiration from lungs. The air of environment can reach the air of lungs through nasal passage easily. Diaphragm is contracted due to neurological excitement in human. As a result, diaphragm gets down and chest is relaxed.
If the volume of the chest increases then the air pressure decreases. As a result the air pressure decreases in lungs than the air pressure outside. To maintain balance between the outside and inside of chest air can easily enter the lungs. Then diaphragm relax and it gets upper and the volume of the chest comes back to normal state. By this the air pressure in lungs increases and CO2 and water vapoured air is evolved. By this way, through external respiration the inspiration respiration of O2 and CO2 is occured.
D. P and Q are dependent on one another in connection with gaseous exchange Explain.
Ans: Through figure P and Q exchange of gas between human and plants are shown respectively.
Through photisynthesis process O2 produced in plant body influences the atmosphere. Human receives this air through respiration. CO2 produced in respiration process is evolved to the nearest atmosphere through stomata. As a result, through exchange of O2 and CO2 in a definite environment plants and human become dependent to each other.
2. Rashed and Jamil works in ship breaking industry. Both of them types of tests, the doctor diagnosed that Rashed's respiratory organ has irregular cell division. On the other hand Jamil's disease has spread in intestine and bones along with respiratory organs.
A. What is the diaphragm?
Ans: Diaphram is muscular sheet which separates the thoracic cavity from the abdominal cavity.
B. What is external respiration?
The biological process, in which digested food susbtances in the body cell are oxidized, converts the potential energy into usable energy and eliminates CO2 is called respiration.
C. Explain how does the disease spread in Rashid's body.
Through mitosis cell division cell number incresse from one to two, two to four, For any reason, if the control is lost then irregular cell division occurs. For this reason tumour is created which may form cancer. In research it is seen that two genes named E6 and E7 of papillona virus create some chemical compound which distracts two protein molecules. As a result irregular cell division occurs and bubble is formed. Many times it is seen that these two genes meet with host cell and the function of the old protein cell is stopped. Cancer cell is produced. In the respiratory organ of Rashed, due to irregular cell division tumour is created which may result in cancer. Polluted environment asbestos and different hard compound causes cancer in trachea. For doing work in this type of enviroment irregular cell division occurs in body and as a result this type of disease is occurred.
D. Which one of the two diseases of Rashed and Jamil is comparatively easier to be cured? Analyse.
Ans: Due to the different types of germs various types of diseases are created in human body. Due to modern treatment most of the diseases can be cured. But there are some diseases which are incurable. A disease like cancer is spread in Rashed's respiratory organ. On the other hand due to Mycobacterium tuberculosis bacteria. So by seeing the symptoms of Jamil it can be understood that he is suffering from tuberculosis can be cured and the body can be kept healthy. For example, if the B.C.G is vaccinated to children then this disease will not occur in future. If tuberculosis occurs then some rules according to doctor's prescription must be maintained. And if regular medicine is taken as per doctor's then this disease can be cured. By this way the disease of Jamil can be cured. On the other hand Rashed has cancer in lungs nad for this reason irregular cell division occurs. The symptoms of this disease should be noticed fast and treatment should be given. By this patient can live much longer. Otherwise it becomes serious which is the reason of death of patient. So, the disease of Jamil is much easier than the disease of Rashed.
Lung Cancer:
Causes:
a) Lung cancer may be caused by air and environmental pollution, coming in contact with pollutants like asbestos, arsenic, chromium, nickel, solid metal poder.
b) Tuberculosis or any other pneumonia causes one type of wound that afterwards turns into cancer.
Symptoms:
a) long lasting dry irritating cough
b) chest pain, hoarseness of voice
c) gradual or day by day loss of weight, loss of appetite
d) asthma, frequent fever
e) repeatedly infected by pneumonia and bronchitis
f) feel pain in bones, weakness, paralysis of any gland , jaundice
Diagnosis:
X-ray
CT scan
MRI
Remedy-
When the symptoms are found, consult the physician without any delay.
After the disease is diagnosed, treatment should be taken as per the advice of the physician.
Depending upon the necessity, use or apply radiotherapy.
Prevention:
According to the view, preventive measures include-
a) Abstaining from smoking and drinking alcohol.
b) Not taking excess fatty food.
c) Regular exercise
d) Making the habit of taking adequate amounts of vegetables.
Pneumonia
Pneumonia is a lung disease. Excessive cold may cause this disease. Getting affected by cold after measles and bronchitis may lead to pneumonia. It is a dangerous disease for children and elderly people.
Q.1. What are the causes of Pneumonia?
Cause:
Pneumonia is caused by Pneumococcus bacteria. Pneumonia may also be caused by viruses, bacteria or fungi. This disease may even occur enzymes or saliva gets into the trachea.
Symptoms:
These include -
* Deposition of mucous like liquid substances which produce cough. Coughing and breathing distress.
* High fever and chest pain.
* Severe respiratory distress, at the last stage whizzing sound in the chest.
Remedy:
1. Seeking timely advice from a physician and to follow the treatment given.
2. serving hot and liquid nutritious diet.
3. Drinking plenty of water.
Prevention:
1. To be careful that the children and elders are not attacked with cold.
2. live in well ventilated house.
3. keep the patient in tolerable temperature and dry environment.
4. Avoid smoking.
Q.1. Describe the structure of gas exchange system.
Ans: The organs, which take part is respiration are called the respiratory system or gas exchange system.
The organs related with the respiratory system are Nasal cavity -
e) Bronchus Pharynx
f) Lungs c) Larynx
g) Diaphragm
d) Trachea
a) Nasal cavity:
Usually air enters the body through the two external nostrils. Its front side is covered with cilia and the near part is lined by mucous producing membrane.
b) Pharynx:
At the end of the nasal passage are two openings, the internal nares, through which air passes into the pharynx.
c) Larynx:
It is situated below the pharynx and at the top of the trachea. There are two folds of muscle situated on opposite sides of the larynx. These are the vocal cords. d) Trachea: This is a long tube which lies in front of the oesophagus and extends from the larynx downwards into the thoracic cavity.
e) Bronchus:
The lower end of the trachea is divided into two bronchi which lead to the right and left lung lobes respectively. These are bronchi (singular: bronchus).
f) Lungs:
The Lungs are the main organ of the respiratory system. The right and left lungs are situated on either side of the heart within the thoracic cavity.
g) Diaphragm:
The Diaphragm is a muscular sheet which separates the thoracic cavity from the abdominal cavity.
Q.2. How alveolus is adapted to its function?
Gaseous exchange in the lungs takes place by diffusion. Blood entering the lungs contains little O2 but much CO2. Air takes in during inspiration contains much oxygen but little CO2. Such a diffusion gradient with an oxygen concentration higher in the alveolar air than in the blood and a CO2 concentration higher in the blood than in the alveolar air can be maintained in two ways: Continuous flow of blood through the blood capillaries Breathing air in and out of the alveoli.
Q.3.Describe how gas exchange take place in alveolus.
Ans: the lungs contain numerous air sacs called alveoli, small bronchioles and blood vessels. The smaller bronchioles terminates in crusts alveoli. So, air can enter from the nasal passage to the alveoli directly. Each alveolus wall is composed of a single layer of epithelial tissue. The alveoli are surrounded by mesh work of capillaries. When air enters the alveolus, it expands like a balloon and later contracts automatically. The wall of the alveoli and blood capillaries are so thin that gaseous exchange occurs between them.
Q.4. Describe the process of inhalation and exhalation process with diagram.
Ans: When we breathe in, the external intercostal (rib) muscles contract while the internal intercostal muscles relax. The diaphragm goes downwards and the thoracic cavity expands. The volume of the thoracic increases and the air pressure decreases. So, the pressure within the thoracic cavity becomes less than the outer atmospheric pressure. This forces the lungs to expand and draw in air through the nose and trachea. This is inhaling. After the contraction the muscles relax. Then the diaphragm expands and the muscles relax, allowing the diaphragm and thorax to return to normal position. So, the air pressure increases, the lung shrinks back, forcing the moistened and CO2 enriched air out again.