Class 10 Biology Notes Biology Class 10 Notes Chapter 10 Gaseous Exchange Short Questions, Long question Review Questions. Easy notes that contain review questions of chapter 10.
Biology Class 10 Notes Chapter 10 Gaseous Exchange Short Questions | Long question
Short Questions Gaseous Exchange Biology Class 10 Notes
Q.1) Why do plants not need a specialized respiratory system?
Answer:
In the day time plant take in CO2 and release O2, by making energy from sunlight through Photosynthesis. In the night Plant takes in O2 and release CO2 but very limited. Plants take in O2 during night and CO2 during day, through their leaves surface opening called stomata, and inside plant body, direct exchange of gases takes place between cell and air. That is the reason that Plants do not need a specialized respiratory system.
Q.2) Differentiate between the terms “respiration” and “breathing”.
Answer:
Respiration:
It is an energy-releasing process at the cellular level. In this process, food molecules are broken down into simpler compounds like carbon dioxide and water with the release of energy.
Breathing:
It is a physical process in which animals move air into and out of their body. It is done to get oxygen from the air and to release carbon dioxide in it.
Q.3) How are the surface area of leaves and lungs important for gaseous exchange?
Answer:
Surface of leaves contains special openings for the gaseous exchange known as stomata. Through these openings, O2 during the day time and CO2 during the night is absorbed and CO2 during night and O2 during the day is released.
Same in animals the surface of lungs has got special openings called alveoli which absorb and transfer O2 into the blood for cellular respiration.
Q.4) What is the function of the cartilage present in the walls of the trachea and bronchi?
Answer:
Trachea has the C shaped cartilage rings which prevents it from collapsing and keeps the passage of air open, bronchi also contains these rings but are smaller in size.
Q.5) What is a diaphragm and what is its role in breathing?
Answer:
Diaphragm is stomach wall and is below the lungs. It contracts during Inspiration (taking in air) to provide the place so pressure on the lungs to decrease. And during Expiration diaphragm become dome shaped so applying maximum pressure on lungs to release air in the environment.
Q.6) What are carcinogens? Name any two carcinogens present in tobacco.
Answer:
Carcinogen are those compounds or chemicals which has the ability to cause cancers. Tobacco smoke contains 69 carcinogens.
1. Benzene
2. Formaldehyde
Q.7) Compare the composition of inhaled and exhaled air.
Answer:
| Inhaled Air | Exhaled Air |
|---|---|
| O2 | CO2 |
Read more:
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Long Questions Biology Chapter 10 Class 10 Notes
Q.1) The gaseous exchange in plants is important for photosynthesis and respiration. Explain the types of gases exchanged and its mechanism.
Answer:
Photosynthesis:
During day time, All plant cells are carrying out respiration. The green parts (leaves) of plants are also carrying out photosynthesis. For photosynthesis, the leaves use carbon dioxide which is produced during respiration. they also take carbon dioxide from the environment. For respiration, leaves use oxygen which is produced during photosynthesis. So, during daytime leaves are taking carbon dioxide from the environment and releasing oxygen in it.
Respiration:
During the night, all cells are carrying out respiration while there is no photosynthesis. So, the cell gets oxygen from the environment and release carbon dioxide.
Mechanism:
The gaseous exchange occurs through the surface. The outer surface of the root, stem, and leaves are called epidermis. This layer allows the exchange of gases between the inner cell and the environment. At some part, a thick cuticle is present over the epidermis. It also allows the exchange of gases.
In leaves and young stems, the epidermis has small pores called stomata. In these parts, the air moves in and out through the stomata. Inside the body, gaseous exchange occurs between the cell and air. In woody stem, the entire surface is covered by bark. Gaseous exchange cannot occur through the bark. The bark contains special pores called lenticels, Which allow the gaseous exchange with the environment.
Q.2) Describe the mechanism of breathing in human beings.
Answer:
Breathing consists of two phases, the taking in of air called inspiration and letting out of air called expiration. These two phases take place continuously one after the other. Air moves in when the air pressure in the lungs is lower than the pressure in the lungs is greater than the atmospheric pressure.
A. Inspiration:
During inspiration, the volume of the chest cavity increases and the pressure in the lungs decreases. It happens due to two reasons;
- The muscles of the diaphragm contract, so it becomes flat instead of its domed position.
- The inter-costal muscles present between the ribs, contract. Due to their contraction, the rib cage expands.
Due to these movements the volume of the chest cavity increases and pressure on lungs decreases. As a result, the atmospheric air rushes into the lungs through the air passage.
B. Expiration:
During this process, the muscles of the ribs and the diaphragm relax. the rib cage goes down to original position and diaphragm becom domed-shaped. The volume of the chest cavity is decreased. It increases pressure on the lungs to expel the air out.
Q.3) Draw a diagram of the air passage in human body and describe the role of different parts in the flow of air through it.
Answer:
When air enters the body, it passes through connected tubes to reach the lungs. After the gaseous exchange, air moves from the lungs to the outside through the same connected tubes. These connected tubes are collectively called the air passageway. It consists of nostrils and nasal cavities, pharynx, larynx, trachea, bronchi, and bronchioles.
i. Nostrils:
Two openings or external nostrils lie on the ventral side of the head. They allow the air from the outside into two nasal cavities. Here the air is warmed, moistened and dust freed by the hairs and the mucous membrane of the nasal cavity.
ii. Pharynx:
The nasal cavities lead into the pharynx which is about a 4.5 inches long muscular passage. It is also lined by the mucous membrane.
iii. Larynx:
The air then moves from pharynx to larynx or voice box. It surrounds the upper part of the trachea. The cavity of the larynx is also lined by the mucous membrane. At the back of the pharynx are two passages, one opens into the esophagus on the dorsal side and other opens through the glottis into the trachea on the ventral side. The glottis is guarded by a lid like structure called epiglottis.
iv. Trachea:
The larynx opens into the trachea or windpipe. It is a tubular structure. It lies ventral to the esophagus and extends to the chest cavity or thorax. The inner surface of the trachea has 16 to 20 C-shaped cartilaginous rings, which prevents it from collapsing and keep the passage open for air.
v. Bronchi:
Inside the thorax, the trachea divides into two branches called bronchi. Each bronchus enters the lung on its own side. The bronchi also possess the cartilaginous rings but smaller than those of the trachea. Each bronchus, on entering the lungs, divides and subdivides progressively into smaller bronchi.
vi. Bronchioles:
When the smaller bronchi attain the diameter of one millimeter or less, then they are called Bronchioles. They have no cartilage.
Each bronchiole ends in a duct. The duct opens in a cluster of pouches, which resemble bunches of grapes. Each pouch is a microscopic structure and is called alveolus (plural alveoli). Alveoli is thin-walled and provide the surface. Their wall is covered by the blood capillaries where gaseous exchange occurs.
Q.4) What are the causes of respiratory disorders such as bronchitis, pneumonia and lung cancer.
Answer:
Sometimes the normal functioning of the respiratory system is disrupted due to certain factors which can lead to serious respiratory disorders.
i. Bronchitis:
It is the disease of the lining of the bronchi when it is infected this condition is known as bronchitis.
It reduces the amount of air that flows in the air bronchi and causes the formation of mucus in the airways. Bronchitis is caused by viruses, bacteria, and particles that irritate the bronchial tubes.
Short-term bronchitis resolves without treatment in two weeks. If conditions do not improve, the patient is given medicines. Antibiotics are used when bronchitis is due to bacterial infection. When bronchitis is due to viral infection, antiviral medicines are used. Coughing helps to remove irritants from the bronchi.
ii. Pneumonia:
Pneumonia is an inflammation in the lungs, due to infection in the alveoli. Due to pneumonia, the alveoli are filled with pus. it is caused by bacteria, viruses, or fungi. General symptoms of pneumonia are;
- Cold
- Sneezing
- Sore throat
- Cough
- HIgh fever
- Shaking chills
- Cough with sputum
iii. Lung Cancer:
Lung cancer is also a respiratory disease, more common in men than women.
Causes:
Causes include;
i. Smoking
ii. Industrial carcinogens
iii. Air pollutions
Symptoms:
i. Cough with sputum
ii. Breathlessness
iii. Pleural chest pain
Mian cause of any cancer is a carcinogen, ionizing radiation, and viral infection. Smoking is the main contributor to lung cancer. Cigarette smoke contains over 69 known carcinogens.
In the early stages, lung cancer does not show any symptoms. However, in the advanced stage when it has fully spread, it is very painful and incurable and becomes fatal. The patient of lung cancer is given one or more treatments, including surgery, chemotherapy, and radiation therapy.
