Problem 15 - Objective Biology for NEET

Question

Kingdom monera contains (a) Bacteria (b) Dinoflagellate (c) Slime moulds (d) Euglenoid

Step-by-Step Solution

Answer

The correct option is (a) Bacteria.

Step 1: Understand the Kingdoms in Biological Classification

There are mainly five kingdoms in biological classification: Monera, Protista, Fungi, Plantae, and Animalia. Monera includes all the single-celled prokaryotes, such as bacteria. Protista includes protozoans, slime molds, and algae, like dinoflagellates. Fungi includes yeasts, molds, and mushrooms. The Euglenoids are a large group of protozoa, and they are included in protista, not monera.

Step 2: Identify the Organisms in Monera

Based on the classification, the organisms belonging to Monera are all unicellular organisms with a prokaryotic cell organization, such as bacteria.

Step 3: Choose the correct option

From the given options, bacteria belong to kingdom Monera and not the rest. Therefore the correct option is (a) Bacteria.

Key Concepts

Biological Classification

Biological classification is the method by which scientists categorize and organize all forms of life. This field of biology is essential for understanding the relationships between different organisms and grouping them according to shared characteristics.

• The major system of classification today was developed by Carl Linnaeus and is based on a hierarchical structure.
• This system is divided into kingdoms, phyla, classes, orders, families, genera, and species.
• The five-kingdom classification includes Monera, Protista, Fungi, Plantae, and Animalia.

Each kingdom groups organisms that share key characteristics. Monera includes single-celled organisms with prokaryotic cell structures, while Protista includes more complex, often single-celled organisms. Understanding this classification is pivotal for studying biology as it lays the groundwork for how we perceive and interact with the natural world.

Prokaryotes

Prokaryotes are a type of organism characterized by the absence of a membrane-bound nucleus. These organisms are simple and small, often existing as single-celled entities.

• Prokaryotes are divided into two groups: bacteria and archaea.
• Unlike eukaryotic cells, prokaryotic cells lack most organelles such as the Golgi apparatus and endoplasmic reticulum.
• They reproduce asexually, primarily through a process known as binary fission.

Prokaryotes are incredibly versatile and can survive in a wide range of environments. They play crucial roles in the ecosystem, including decomposing dead organisms and fixing nitrogen in the soil, which are fundamental processes for life on Earth.

Bacteria

Bacteria are one of the most prominent groups within the kingdom Monera. These prokaryotic organisms are exceptionally diverse and are found virtually everywhere on Earth.

• Bacteria can be classified based on shape, such as cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
• They are capable of living in various environments, from extreme heat to intense cold, both inside and outside living organisms.
• Many bacteria play beneficial roles, such as aiding in digestion and decomposing organic matter, though some can be pathogenic and cause diseases.

Bacteria's simple cell structure allows them to multiply rapidly and adapt to new environments, which is why they are so successful in so many different niches.

Protista

The kingdom Protista is a diverse group of eukaryotic organisms, which means their cells have a defined nucleus.

• Protists can be unicellular or multicellular, autotrophic like algae, or heterotrophic like protozoans.
• This kingdom acts as a catch-all for organisms that do not fit neatly into the other kingdoms of Plantae, Animalia, or Fungi.
• Some well-known protists include dinoflagellates, slime molds, and algae.

Although protists are diverse, they often share living environments such as moist or aquatic habitats. They play significant roles in ecosystems, particularly as primary producers in aquatic food chains and as decomposers, breaking down organic materials in the environment.