Respiration is an essential process in organisms for several reasons. Listed below are some reasons why respiration is significant in all organisms:

1. It produces energy in the body: Energy is an essential component for the proper working of the body. Respiration helps in creating this energy so that the organism can function efficiently.

2. Provides oxygen to the body: Oxygen is an essential requirement to convert food into energy. The process of respiration helps in the transfer of oxygen to the body. It also helps in exhaling and eradicating carbon dioxide from the body.

This is a crucial process that transfers cellular oxygen to the body and carbon dioxide to the surroundings. The mitochondrion is the place where cellular respiration takes place. Glucose and oxygen come together in the mitochondria. The carbon dioxide transfers from the lungs to the surroundings through the blood. Oxygen also helps in releasing carbon dioxide through food. Carbon dioxide is an essential requirement for the livelihood of flora, that is, plants, trees etc. Cellular respiration takes place in all living organisms.

Types of Respiration

Listed below are the two types of respiration:

1. Aerobic Respiration: This takes place with the help of oxygen and releases a high amount of energy. The oxygen present in the body breaks down the glucose to release energy. Therefore, aerobic respiration breaks down glucose and releases carbon dioxide, water and energy. It takes place in the mitochondria. The best example of aerobic respiration is human beings who inhale oxygen and exhale carbon dioxide. Aerobic respiration also occurs in other living organisms like fish, buffaloes, earthworms, frogs etc.

2. Anaerobic Respiration: This takes place without the help of oxygen. Since oxygen is not involved in this type of respiration process, the energy release is also lower than the energy output of aerobic respiration. It forms an intermediate compound along with the release of energy. Therefore, the organisms with energy also release alcohol and carbon dioxide. This type of respiration generally occurs in yeasts and bacteria. Some yeasts that have anaerobic respiration include Saccharomyces cerevisiae. The organisms with anaerobic respiration are also known as anaerobes. Human beings also undergo this type of respiration sometimes in the muscles due to the temporary lack of oxygen.

Respiration in animals is a continuous process. The air goes in through the nostrils. It then reaches the nasal cavity. The air then goes to the lungs through the windpipe. The lungs are situated in the chest cavity of the body. The chest cavity is made up of ribs to protect the vital organs. It also consists of the diaphragm that forms the chest floor. The process of respiration in human beings involves the movement of the diaphragm and ribs. It involves inhalation and exhalation. Respiration is essential for the human body to function.

Breathing In or Inhalation

Breathing involves the intake of oxygen in the body. The body needs oxygen to keep functioning. The process of inhaling enables the body to get enough oxygen. During the inhalation process, the ribs surrounding the chest cavity move upwards, and the diaphragm moves downward. This process creates a space in the chest cavity that enables the air to flow into the lungs. In this way, the lungs fill up with air. The inhalation process precedes the breathing out or the exhalation process.

Breathing Out or Exhalation

Breathing out involves the release of carbon dioxide from the body to the surroundings. Carbon dioxide is harmful to the human body but essential for plants. Therefore, the human body releases it through the process of exhalation. During the exhalation process, the ribs surrounding the chest cavity move downwards, and the diaphragm moves upwards. Therefore, the size of the lungs decreases and the lungs release carbon dioxide. Exhalation is essential to keep the human body functioning. It is also vital for eliminating the harmful carbon dioxide from the human body. 

Respiration in other animals

Respiration in other animals is slightly different from the human respiratory system. Some animals like lions, cows and elephants have similar chest cavities as human beings, but other organisms like cockroaches and earthworms have different respiratory systems. A cockroach has small openings, also known as spiracles, in their bodies. They also have air tubes in their body known as trachea. Oxygen passes through the spiracles and goes to the trachea. It then diffuses into the tissues and spreads across the whole body. The carbon dioxide moves out from the trachea through the spiracles. This respiratory system is present only in insects. Unlike insects, earthworms and frogs breathe through their skins. Hence, skin of the earthworms feels slimy. Air can easily pass through their skins. Therefore, their skins play a vital part in conducting the respiratory process in earthworms and frogs. Frogs have lungs, too, that help in the respiration process.

Respiration in Plants 

Respiration in plants also includes absorbing oxygen and giving out carbon dioxide. Plant leaves contain microscopic pores known as stomata that help transfer oxygen and carbon dioxide. The root of the plants requires oxygen to function. Therefore, they take in oxygen from the spaces between the soil particles. In this way, each part of the plant takes oxygen independently and emits carbon dioxide into the surroundings.

1. Why do human beings sneeze when they inhale dust?

When dust is inhaled, it causes irritation in the nose and results in sneezing. Sneezing eliminates the dirt that enters the nose. It happens because the dust disturbs the mucus lining present in the nostrils. The dirt sometimes also gets trapped in the nostril hair and irritates the nose. Other times, the dust may pass into the nasal cavity. Hence, human beings sneeze when they inhale the dust.

2. Mention some similarities between aerobic and anaerobic respiration.

Aerobic and anaerobic respiration are types of respiration in living organisms. The main similarity between these two types of respiration is that both processes break down food particles to release energy in the body. Both aerobic and anaerobic respiration aims at helping the body function. They also release carbon dioxide along with other by-products. Aerobic and anaerobic respiration use glucose as the initial material to start the respiration process. Both aerobic and anaerobic respiration also take place inside the cells of the organisms.

3. What are the differences between aerobic and anaerobic respiration?

The primary difference between aerobic and anaerobic respiration is that the former uses oxygen, and the latter does not. Anaerobic respiration produces alcohol as a by-product of the respiration process whereas aerobic respiration does not. Aerobic respiration is primarily found in humans and animals, while anaerobic respiration occurs in yeast and bacteria. Aerobic respiration involves the transfer of air from outside to inside the body. Anaerobic respiration also includes the transfer of air but without oxygen. Glucose breaks down into alcohol, carbon dioxide and energy in anaerobic respiration, and glucose breaks down into carbon dioxide, water and energy in aerobic respiration. 

4. Which soil is the most fertile and why?

The most fertile soil is loamy soil. Loamy soil consists of three equal parts of clay, sand and silt. This property helps this type of soil to retain an adequate amount of water and nutrients for the plants to grow. It also consists of smaller and larger particles that help balance the structure and give it the perfect texture for the plants to grow. This soil is not too sticky or grainy. Therefore, loamy soil is the most fertile soil.

All living organisms require respiration to function and survive properly. It is a continuous process that keeps living organisms alive. Respiration is also essential in conducting bodily functions as it creates energy. Students must learn this chapter well to understand the different respiration processes.