Question

Which of these parts in vertebrates functionally corresponds to the contractile vacuole of protozoans? (a) Heart (b) Cloaca (c) Sweat glands (d) Kidneys

Short answer

The kidneys in vertebrates functionally correspond to the contractile vacuole of protozoans as they both serve the role in osmoregulation.

Step-by-step solution

Analyzing the function of Heart

The heart in vertebrates is responsible for pumping blood throughout the body. It does not directly participate in osmoregulation or the removal of excess water. Hence, the heart does not correspond to the contractile vacuole.

Understanding the function of Cloaca

Cloaca is found in some vertebrates and it is a common cavity at the end of the digestive tract for the release of both excretory and genital products. It also does not play a direct role in osmoregulation so it can't be compared to the contractile vacuole.

Evaluating the role of Sweat glands

Sweat glands help in cooling the body by releasing sweat, a process known as thermoregulation rather than osmoregulation. So, this also doesn't functionally correspond to the contractile vacuole in protozoans.

Assessing the function of Kidneys

Kidneys in vertebrates play a crucial role in osmoregulation. They filter the blood and remove excess water, salts and waste products which are then excreted through urine. This functionally corresponds to the role of the contractile vacuole of protozoans.

Key concepts

Vertebrate Organs

Vertebrate organs are a complex and essential part of the anatomy of animals with backbones, including mammals, birds, reptiles, amphibians, and fish. These organs are grouped into organ systems, each serving specific functions necessary for survival. Unlike simpler organisms, vertebrates have a higher level of specialization and organ development.

Some key organ systems in vertebrates include:

• Circulatory System: Includes the heart and blood vessels, crucial for distributing nutrients and oxygen throughout the body.
• Respiratory System: Lungs and airways in terrestrial vertebrates facilitate breathing, while fish use gills for gas exchange.
• Excretory System: Involves organs like kidneys which play roles in waste elimination and maintaining water balance.
• Digestive System: Processes food intake and absorbs nutrients.

Each organ system adapts to its environment and lifestyle, providing vertebrates the flexibility to thrive in diverse habitats. Understanding these systems' roles helps highlight their importance in maintaining homeostasis and adaptation.

Osmoregulation

Osmoregulation is a vital process for maintaining the balance of water and dissolved substances inside and outside the cells of organisms. This process is crucial in ensuring that cells function properly without being either too dehydrated or overhydrated.

In vertebrates, osmoregulation is primarily carried out by the kidneys. Here's how it works:

• Filtration: Kidneys filter blood to remove waste products and excess substances.
• Reabsorption: Useful substances and a necessary amount of water are reabsorbed back into the bloodstream.
• Excretion: The remaining waste, including excess salts and water, is excreted in the form of urine.

This process is essential for homeostasis, which ensures that the internal environment remains stable despite external changes. Different vertebrates have evolved various adaptations in their osmoregulatory processes to meet specific environmental challenges, such as dealing with freshwater, saltwater, or terrestrial habitats.

Contractile Vacuole

The contractile vacuole is a specialized cellular structure found in simple organisms, like protozoans, such as amoebas and paramecia. Its primary function is to manage water balance by expelling excess water from the cell.

Here’s how a contractile vacuole operates:

• Collection: As water diffuses into the organism, it gathers in the contractile vacuole.
• Contraction: Once full, the vacuole contracts, forcing the water back out of the cell.
• Regulation: This process helps prevent the cell from bursting and maintains osmotic balance.

In more complex organisms, like vertebrates, similar functions are performed by organs rather than cellular structures. For example, the kidneys in vertebrates have a comparable function. They filter excess water from blood, thereby maintaining fluid balance within the organism. This comparison helps illustrate the evolutionary shift from unicellular water management mechanisms to complex organ systems.