10th Biology Notes Chapter 10 Gaseous Exchange

Welcome to the world of 10th class biology! In this chapter, we will explore the fascinating topic of Gaseous Exchange. Breathing is an essential process that sustains life in all living organisms, and understanding how gases are exchanged in our bodies and other organisms is crucial to comprehending the mechanisms that keep us alive.

From the intricate structures of respiratory systems to the transportation of gases through various biological processes, these biology notes will provide you with a comprehensive understanding of gaseous exchange, shedding light on the intricate dance of life and respiration. So, let’s dive into the intricacies of Gaseous Exchange and unravel the mysteries behind the breath of life.

Unit 10 Gaseous Exchange of Biology Long Questions

Unit 10 Gaseous Exchange of Biology MCQ’s

Unit 10 Gaseous Exchange of Biology Short Questions

What is gaseous exchange?
Answer: Gaseous exchange is the process through which organisms take in oxygen from their environment and release carbon dioxide.

How do organisms obtain the oxygen needed for cellular respiration?
Answer: Organisms get the oxygen needed for cellular respiration from their environment.

What is the difference between breathing and respiration?
Answer: Breathing is the process of taking air into the body to get oxygen and expelling air to get rid of carbon dioxide. Respiration involves both mechanical and biochemical processes.

How do plants exchange gases with the environment?
Answer: Plants exchange gases with the environment through stomata present in the leaves and young stems. Air spaces among the inner cells of leaves and stems also aid in gaseous exchange.

What are lenticels, and where are they found?
Answer: Lenticels are pores found in the layer of bark of woody stems and mature roots. They allow air to pass through for gaseous exchange.

How do aquatic plants obtain oxygen and release carbon dioxide?
Answer: Aquatic plants obtain oxygen dissolved in water and release carbon dioxide into the water.

When do leaf cells utilize oxygen and carbon dioxide differently?
Answer: During the daytime, when photosynthesis and respiration occur simultaneously in leaf cells, the oxygen produced in photosynthesis is utilized in cellular respiration, and the carbon dioxide produced during respiration is utilized in photosynthesis. During the night, oxygen is obtained from the environment, and carbon dioxide is released through stomata.

What is the respiratory system responsible for in humans and higher animals?
Answer: The respiratory system is responsible for the exchange of gases in humans and higher animals.

How can we divide the respiratory system?
Answer: The respiratory system can be divided into two parts: the air passageway and the lungs.

What is the purpose of the stoma in leaves?
Answer: The stoma is an opening through which leaves exchange gases, allowing for the process of photosynthesis and respiration.

When do the cells of leaves carry out photosynthesis?
Answer: The cells of leaves carry out photosynthesis during daytime only.

When do the cells of leaves carry out respiration?
Answer: The cells of leaves carry out respiration all the time.

What is the procedure for observing stomata in a leaf?
Answer: The procedure involves taking a thick leaf, peeling off a thin layer (epidermis) from its surface, placing the epidermis in water on a glass slide, adding methylene blue, and observing under a microscope.

What is the evaluation question regarding stomata observation?
Answer: How many stomata did you observe?

Describe the structure of guard cells and their role in stomata opening and closing.
Answer: Guard cells surround the stomata and can change shape to open or close the stomata, regulating gas exchange and water loss in the leaf.

What are the parts of the air passageway in the respiratory system?
Answer: The air passageway consists of the nose, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

What is the function of the epiglottis in the respiratory system?
Answer: The epiglottis guards the glottis, preventing food from entering the windpipe during swallowing.

What are the vocal cords, and what do they do?
Answer: The vocal cords are fibrous bands in the larynx that vibrate when air passes through them, producing sounds and enabling speech.

What is the role of the alveoli in the respiratory system?
Answer: The alveoli form the respiratory surface in the human body, where the exchange of gases (oxygen and carbon dioxide) occurs between the lungs and blood.

How does oxygenated blood return to the heart from the lungs?
Answer: The oxygenated blood returns to the heart through the pulmonary vein.

What produces specific sounds that result in speech?
Answer: The vibrations in vocal cords and the movements of lips, cheeks, tongue, and jaws produce specific sounds that result in speech.

What is the ability that only humans possess, setting them apart from other beings?
Answer: Speech is an ability that only humans are gifted with, and it is one of the characteristics that make human beings superior to all.

What are the functions of ciliated and glandular cells in the trachea and bronchi?
Answer: The glandular cells secrete mucus to moisten the air and trap fine particles of dust or bacteria that escaped from the nasal cavity. The cilia beat with an upward motion to move the foreign particles along the mucus to the oral cavity, where they can be either swallowed or coughed out.

What is the structure below the lungs, involved in the mechanism of breathing?
Answer: The thick muscular structure called the diaphragm is present below the lungs and is involved in the mechanism of breathing.

How many lobes does the left lung have, and how does it compare to the right lung?
Answer: The left lung has two lobes, and the right lung is bigger with three lobes.

What are the two phases of breathing, and what happens during each phase?
Answer: The two phases of breathing are inhalation and exhalation. During inhalation, the rib muscles contract, raising the ribs, and the diaphragm contracts and lowers, increasing the thoracic cavity’s area and allowing air to rush into the lungs. During exhalation, the rib muscles and diaphragm relax, reducing the chest cavity’s space and forcing the air out of the lungs.

What controls the rate of breathing in humans?
Answer: The rate of breathing is controlled by the respiratory center in the brain, which is sensitive to the concentration of carbon dioxide in the blood.

Why does the rate of breathing increase during exercise or hard physical work?
Answer: During exercise or hard physical work, muscle cells carry out cellular respiration at a greater rate, resulting in the production of more carbon dioxide. The increased concentration of carbon dioxide in the blood stimulates the respiratory center in the brain, leading to an increased rate of breathing to remove the excess carbon dioxide from the body.

What is the amount of oxygen in inspired air?
Answer: 21%

What is the amount of oxygen in expired air?
Answer: 16%

What is the amount of carbon dioxide in inspired air?
Answer: 0.04%

What is the amount of carbon dioxide in expired air?
Answer: 4%

What is the amount of nitrogen in inspired air?
Answer: 79%

What is the amount of nitrogen in expired air?
Answer: 79%

How does the amount of water vapors differ between inspired and expired air?
Answer: Inspired air is variable in water vapors, while expired air is saturated.

How do the dust particles compare between inspired and expired air?
Answer: Inspired air has variable dust particles, while expired air has almost none.

How does the temperature of inspired air compare to the temperature of expired air?
Answer: The temperature of inspired air is variable, while expired air is almost equal to body temperature.

What is bronchitis?
Answer: Bronchitis is the inflammation of the bronchi or bronchioles, resulting in excessive mucus production and narrowing of the airways.

What are the two major types of bronchitis?
Answer: Acute bronchitis and chronic bronchitis.

What causes bronchitis?
Answer: Bronchitis can be caused by viruses, bacteria, or exposure to chemical irritants like tobacco smoke.

What is emphysema?
Answer: Emphysema is the destruction of the walls of the alveoli, leading to larger sacs with less surface area for gaseous exchange.

What are the symptoms of emphysema?
Answer: Shortness of breath, fatigue, recurrent respiratory infections, and weight loss are symptoms of emphysema.

What is pneumonia?
Answer: Pneumonia is an infection of the lungs, often caused by bacteria, viruses, or fungi.

How can pneumonia affect the alveoli?
Answer: Pneumonia can lead to fluid and pus filling the alveoli due to the growth of causative organisms.

What are the symptoms of pneumonia?
Answer: Symptoms of pneumonia include high fever, shivering, cough with sputum production, shortness of breath, and dusky skin color due to poor oxygenation.

What is asthma?
Answer: Asthma is a form of allergy characterized by inflammation of the bronchi, increased mucous production, and narrowing of the airways.

What are the symptoms of asthma?
Answer: Symptoms of asthma include shortness of breath, wheezing, cough, and chest tightness.

What is the most common cause of lung cancer?
Answer: Smoking is the main cause of lung cancer, as cigarette smoke contains over 50 known carcinogens.

What is the World No Tobacco Day and when is it celebrated?
Answer: The World No Tobacco Day is celebrated on May 31st every year.

How does smoking affect the body?
Answer: Smoking affects the body from head to toe, increasing the risk of various life-threatening diseases and respiratory disorders.

How does passive smoking (second-hand smoke) affect non-smokers?
Answer: Non-smokers exposed to second-hand smoke increase their risk of heart disease by 25-30% and lung cancer by 20-30%.

What is the current trend in smoking rates in the developing world according to the WHO?
Answer: Smoking rates are rising by 3.4% per year in the developing world as of 2002.

How do the different parts of the plant body exchange gases with the environment?
Gaseous Exchange in Plants:
Plants exchange gases with the environment through specialized structures called stomata, which are small openings present on the surface of leaves and young stems. These stomata allow the exchange of gases like oxygen and carbon dioxide between the internal tissues of the plant and the surrounding atmosphere.
In addition to stomata, gaseous exchange also occurs through the cuticle, a waxy layer on the surface of leaves and stems. The cuticle is not as efficient as stomata in gas exchange but still plays a role in this process.

In woody stems and mature roots, gas exchange occurs through small pores called lenticels, which allow air to pass through the bark and exchange gases with the surrounding environment. In aquatic plants, gases are exchanged through the dissolved gases in water.

Write down the steps of inhalation and exhalation.
Steps of Inhalation and Exhalation:

Inhalation (Breathing In):

  1. The diaphragm, a dome-shaped muscle located at the base of the chest cavity, contracts and moves downward.
  2. The rib muscles contract, causing the ribcage to expand outward.
  3. These movements increase the volume of the thoracic (chest) cavity, lowering the air pressure inside the lungs.
  4. As a result, air from the outside rushes into the lungs through the airways (trachea, bronchi, and bronchioles) to equalize the pressure.


Exhalation (Breathing Out):

  1. The diaphragm and rib muscles relax.
  2. The ribcage moves back to its resting position, and the diaphragm moves back upward.
  3. The volume of the thoracic cavity decreases, increasing the air pressure inside the lungs.
  4. As a result, air is forced out of the lungs and expelled through the airways to the outside.

State the signs and symptoms, causes and treatments of bronchitis, emphysema and
pneumonia.

Respiratory Disorders – Signs, Symptoms, Causes, and Treatments

a) Bronchitis
Signs and Symptoms: Cough, mucus production, shortness of breath, wheezing, fever, and chills.
Causes: Viral or bacterial infections, exposure to chemical irritants (e.g., tobacco smoke).
Treatment: Rest, hydration, bronchodilators, and sometimes antibiotics for bacterial infections.

b) Emphysema
Signs and Symptoms: Shortness of breath, fatigue, recurrent respiratory infections, and weight loss.
Causes: Mainly due to long-term smoking or exposure to air pollution.
Treatment: No cure, but management includes quitting smoking, bronchodilators, oxygen therapy, and pulmonary rehabilitation.

c) Pneumonia
Signs and Symptoms: Cold followed by high fever, shivering, cough with sputum production, and shortness of breath.
Causes: Bacterial, viral, or fungal infections.
Treatment: Antibiotics for bacterial pneumonia, antiviral drugs for viral pneumonia, and antifungal medications for fungal pneumonia.
Please note that this information is for general knowledge purposes only, and it’s essential to consult a healthcare professional for accurate diagnosis and treatment recommendations for specific medical conditions.

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