Question

Select the total number of organism from the following which respire through their body surface. Sycon, Spongilla, Admsia, Taenia, Laccifer, Pila, Antedon, Gorgonia, Jelly fish (a) 4 (b) 5 (c) 6 (d) 8

Short answer

The total number of organisms out of the given that respire through their body surface is 5. Therefore, the correct answer is (b) 5.

Step-by-step solution

Identify the Organisms

Here's a list of the organisms with brief descriptions to help recognize their respiration method: \n1. Sycon, Spongilla, Admsia are forms of sponge. They are simple multicellular organisms. \n2. Taenia (Tapeworm) is a flatworm. \n3. Laccifer is a lac insect. \n4. Pila is a genus of large freshwater snails. \n5. Antedon is a type of sea lily. \n6. Gorgonia is a form of coral. \n7. Jellyfish, as the name suggests, is a jelly-like creature that lives in the sea.

Determine Respiration Method of Each Organism

Sponges (Sycon, Spongilla, Admsia) and Platyhelminthes (Taenia) are simpler lifeforms. They do not possess specialized respiratory organs, and therefore respire directly through the body surface by diffusion. \nThe Lac insect (Laccifer), snails (Pila), and corals (Gorgonia) respire through specialized organs. \nAntedons respire through their tube feet and Jellyfish respire through their skin and the lining of their oral cavity.

Count the Organisms Respiring Through Their Body Surface

Counting the organisms from the list that respire through their body surface, we find that there are five: three sponges (Sycon, Spongilla, Admsia), one flatworm (Taenia), and a jellyfish.

Key concepts

Sponges Respiration

Sponges, also known as Porifera, are fascinating creatures that exhibit a highly primitive form of respiration. They do not have specialized respiratory organs like lungs or gills. Instead, they rely on the process of diffusion to facilitate gas exchange. Sponges have pores called ostia on their surface, which allow water to flow through their bodies.

As water passes through their bodies, oxygen dissolved in the water diffuses into the sponge's cells, while carbon dioxide, a waste product of cellular respiration, diffuses out.

This simplistic approach to respiration is efficient for sponges due to their porous structure and aquatic environment.

It's important to note that the constant water flow is crucial for sponges, as it not only aids in respiration but also in feeding and waste removal. In the exercise, sponges like Sycon and Spongilla utilize this basic form of body surface respiration.

Body Surface Respiration

Body surface respiration is a process where organisms exchange gases directly across their skin or outer covering. This method is prevalent among simpler lifeforms like certain types of worms and jellyfish. Such organisms lack complex respiratory structures and instead rely on diffusion for gas exchange.

Their skin must remain moist to facilitate the diffusion of gases. Here's how it works:

• Oxygen in the surrounding environment diffuses into the organism's body surface.
• Carbon dioxide diffuses out of the body and into the environment.

This method is only effective in environments where the organism remains wet, as dry surfaces would impede gas diffusion.

In the original exercise, organisms like Taenia (a flatworm) and jellyfish use this method to breathe, showing the diversity and simplicity of respiratory methods in nature.

Respiratory Methods in Animals

Animals have evolved a variety of respiratory methods based on their environmental niches and physiological needs. The complexity of these methods can vary greatly among species.

There are three primary types:

• Body Surface Respiration: Common in simple organisms like sponges, flatworms, and jellyfish, where gas exchange occurs directly through the skin.
• Gills: Specialized structures used by many aquatic organisms, such as fish and some amphibians, for extracting oxygen from water.
• Lungs: Complex respiratory systems found in mammals, birds, and reptiles that allow for gas exchange with the environment.

Additionally, some animals like insects use tracheal systems, which comprise a network of tubes that deliver air directly to tissues.

Understanding these different respiratory methods sheds light on how diverse life forms have adapted to thrive in their chosen habitats. The exercise highlighted how body surface respiration allows certain organisms, like sponges and jellyfish, to efficiently obtain oxygen without the need for complex organs.