Problem 221 - Objective Biology for NEET

Question

Assertion: Cyanobacteria included in kingdom Plantae. Reason: Cyanobacteria belong to algae.

Step-by-Step Solution

Answer

The assertion is incorrect. Cyanobacteria do not belong to the kingdom Plantae, they are a type of bacteria, not plants or algae.

Step 1: Understand the assertion and reason

The assertion claims that cyanobacteria are included in the kingdom Plantae. The provided reason for this is that cyanobacteria belong to algae.

Step 2: Research Cyanobacteria

Understanding the nature and class of cyanobacteria. It is a photosynthetic bacterium, often blue-green in color. It is an algae-like organism, but it is actually a type of bacteria, so it does not belong to the kingdom Plantae.

Step 3: Conclude

Since the Cyanobacteria does not belong to the kingdom Plantae, the assertion is incorrect, therefore the reason, even if slightly related, does not correctly support the assertion.

Key Concepts

kingdom Plantae

The kingdom Plantae is a vast category in biological classification that includes all multi-cellular plants we encounter in our environment. It encompasses a wide range of plant life such as trees, flowers, ferns, and mosses. Plants in this kingdom share common characteristics, such as being eukaryotic, meaning their cells have a nucleus. They are capable of photosynthesis because they have chloroplasts containing chlorophyll.

Photosynthesis allows plants to convert sunlight into energy, a defining and crucial trait. Moreover, plants in this category have a cell wall made of cellulose and a regular reproduction cycle involving a life stage called the embryo.

• Multicellularity
• Chlorophyll presence
• Photosynthesis
• Cellulose cell walls

These traits help distinguish plants from other living organisms, including photosynthetic bacteria like cyanobacteria, which do not fit in the Plantae kingdom due to their prokaryotic nature and differences in cellular structure.

algae

Algae are a diverse group of aquatic organisms that share one key trait: the ability to conduct photosynthesis. They range from single-celled microalgae to large multicellular forms like giant kelp. Algae can be found in various water environments, from oceans to freshwater, and some even in moist terrestrial habitats.

Despite their similarities to plants, algae differ significantly in composition and form. Many algae are simple and lack the complex structures that plants have, such as roots, stems, and leaves. This makes them unique and diverse in their forms and functions.

• Photosynthetic capability
• Habitat diversity
• Structural simplicity

Algae are commonly mistaken as part of the kingdom Plantae due to their photosynthetic abilities. However, they are classified separately due to their lack of protective embryos and different reproductive methods.

photosynthetic bacteria

Photosynthetic bacteria are a fascinating group of microorganisms capable of converting light energy into chemical energy through photosynthesis, just like plants and algae. Cyanobacteria, often called blue-green algae, are a well-known example.

These bacteria are prokaryotic, meaning they lack a true nucleus in their cell structure. This makes them fundamentally different from eukaryotic organisms like those in the kingdom Plantae. Cynobacteria can perform photosynthesis due to their special pigments, such as chlorophyll a and phycobilins, allowing them to capture and utilize light.

• Prokaryotic organization
• Photosynthesis using pigments
• Adaptation to various environments

They are versatile and can be found in a wide range of habitats, from hot springs to arctic lakes. Despite these capabilities, their cellular structure places them far from being classified under the kingdom Plantae.

biological classification

Biological classification, also known as taxonomy, is a method used by scientists to organize and categorize all living organisms on Earth. This system allows for a structured way to identify and study the enormous variety of life forms by grouping them based on shared characteristics.

There are several taxonomic ranks, with kingdom being one of the broadest categories, followed by more specific ones like phylum, class, order, family, genus, and species. Each step down represents a more precise grouping based on finer differences and similarities.

• Organizes biological diversity
• Uses hierarchical structure
• Defines relationships between organisms

This classification helps in understanding evolutionary relationships and ecological functions. Cyanobacteria, due to their unique characteristics, are placed in a separate category distinct from the kingdom Plantae, illustrating the importance of classification in biology.