Respiration in Organisms

Breathing in other animals

All animals respire to survive. Mammals, reptiles, and birds have a respiratory system similar to the respiratory system found in humans. These animals are big. And hence they require more energy. So they need a complex and efficient respiratory system that can fulfill the demand of high energy they require.

Smaller animals such as insects, earthworms, etc. do not require more energy because of their simple body design, as mammals and other big animals do.

In unicellular and very small multicellular animals, respiration takes place through the process of diffusion. For example, earthworms, jellyfish, sponges, etc., use diffusion and osmosis for the exchanges of gas.

Some examples of animals that have some special mechanisms for the exchange of gases are a cockroach, earthworm, fish, frogs, etc.

Respiration in Cockroach

Cockroaches have a network of air canals, known as trachea for the exchange of gas. There are several small holes present on the sides of the cockroach's body. These small holes are called spiracles. Other insects also have similar trachea and spiracles. The trachea and spiracles are not found in animals other than insects.

Air, which contains oxygen, passes from spiracles to tracheae through the process of diffusion. From there the air reaches every cell through diffusion. Similarly, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles.

Respiration in Earthworm

Earthworms have moist and slimy skin. Earthworms respire through their moist and slimy skin. Through their skin gas can easily pass. Oxygen present in the air goes through their skin and reaches their blood cells and carbon dioxide from their blood cells moves out in the atmosphere by a process called osmosis.

Respiration in Frogs

Frogs have lungs and moist and slimy skin both. Frogs can respire through their skin as well as through their lungs. Frog is an amphibian. Amphibian means the animal that can live in water and on land both with equal ease.

When frogs are on land they use their lungs for breathing. But once they are inside the water they breathe through the skin. The air goes through the skin by the process of osmosis. The movement of a material through a membrane is called osmosis. Osmosis takes place in liquid medium.

BREATHING UNDER WATER

Many animals that live in water have different types of respiratory mechanisms using which they can respire underwater.

Respiration in Fish

Fish live in water and take oxygen dissolved in water. To breathe in the water, fish have special types of organs called gills. Gills are present both sides near the head of fish. The gills are of red colour. This colour shows the presence of richly supplied blood vessels. Fish take the oxygen in dissolved in water through their gills. Through the gills of fish, oxygen goes to their blood. And carbon dioxide is expelled out using the same process, i.e. through gills.

Figure¹ : Gills Fish (please see below for reference)

Respiration in plants

Plants also need respiration to live. Plants take oxygen in and release carbon dioxide out. In the cells of plants, oxygen is used to break down glucose into carbon dioxide and water as does in other organisms.

Plants do not have a respiratory system like an animal, although the growth of many plants can be very large. A plant respires through its leaves and branches. Every part of a plant has a porous outer layer. Gases exchange through these minute porous layers. On the surface of leaves, there are several pores like structures found called stomata. Plants respire through these stomata. Gases traverse through these minute pores and thus easily reach the different cells. The exchange of gases in plants takes place through diffusion.

Figure² : Stomata Open (please see below for reference)

Figure³ : Stomata closed (Taken from commons.wikimedia.org See at bottom for reference)

We read about the respiration takes place in living organisms. All living organisms need to respire to fulfill the need for energy. Respiration is a continuous process that is carried out throughout life. Without respiration, no one can survive.

Important Key Words Related to Respiration in Organisms

Inspiration or Inhalation: Taking air in, rich in oxygen through the nostril in process of breathing, is called INSPIRATION or INHALATION.

Expiration or Exhalation: Expelling out the carbon dioxide and moisture through the nostril in the process of breathing, is called EXPIRATION or EXHALATION.

Breathing: Inhalation of air rich in oxygen and exhalation of carbon dioxide is called BREATHING.

In other words, taking oxygen in and expelling out carbon dioxide using nostrils is called BREATHING.

Respiration: The process of burning glucose in cells in the presence of oxygen which gives energy, is called RESPIRATION.

Since the burning of glucose takes place in the presence of oxygen, so, it is also called the oxidation of glucose.

Anaerobic Respiration: Respiration in the absence of oxygen is called Anaerobic Respiration.

Aerobic respiration: Respiration in the presence of oxygen is called AEROBIC RESPIRATION.

Anaerobes: Microorganisms that show anaerobic respiration are known as ANAEROBES.

Lungs: Bag-like structure present in the chest cavity that accommodates air during breathing and facilitates the exchange of gases is called LUNG.

Alveoli: Air sacs, where exchange of gases takes place in the respiratory system, i.e. in lungs are called ALVEOLI.

Gills: Breathing organ present in fish is known as GILLS.

Diffusion: Random movement of gas particles from regions of high concentration to regions of low concentration is known as DIFFUSION.

Osmosis: Flow of solvent through a semi-permeable membrane from low concentration to high concentration is called OSMOSIS.

7-science-home

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Reference:

Figure¹ : Gills Fish By Guitardude012 - Own work, CC BY 3.0, Link

Figure^{2 and 3} : Stomata Open By MS Sakib Original image: User:Ali Zifan - Own work, This file was derived from: Opening and Closing of Stoma.svg: , CC BY-SA 4.0, Link