Slime Moulds: Notes Classification: Slime moulds are saprophytic protists. They feed on decaying organic matter, such as twigs and leaves. Feeding Mechanism: The slime mould’s body moves over decaying matter, engulfing organic material as it progresses. Plasmodium Formation: Under suitable conditions, slime moulds aggregate to form a structure called...
Dinoflagellates: Mostly marine (saltwater) organisms with the ability to photosynthesize (like plants). Appearance: Exhibit a variety of colors (yellow, green, brown, blue, red) depending on the pigments within their cells. Structure: Possess a cell wall with stiff cellulose plates providing structural support. Have two flagella (whip-like structures for movement):...
Chrysophytes Members: Diatoms Golden algae (desmids) Habitat: Freshwater and marine environments Characteristics: Microscopic Planktonic (float passively in water currents) Mostly photosynthetic Diatoms: Unique cell walls: Two thin overlapping shells (like a soapbox) Embedded with silica (indestructible) Form diatomaceous earth: Accumulation of cell wall deposits over billions of years Gritty...
Kingdom Protista General Characteristics: All single-celled eukaryotes Primarily aquatic Serve as a link between kingdoms Plantae, Animalia, and Fungi Cell structure: Well-defined nucleus Membrane-bound organelles Movement: Some possess flagella or cilia Reproduction: Asexual and sexual (cell fusion and zygote formation) Boundaries: Not well-defined; overlap with other kingdoms (especially Plantae) What one...
Archaebacteria: A unique group of bacteria adapted to survive in extreme environments. Key Characteristics: Extremophiles: Thrive in harsh conditions where most other life forms cannot survive. Distinct Cell Wall: Different cell wall structure compared to other bacteria, enabling their survival in extreme environments. Types of Archaebacteria: Halophiles: Live in extremely salty environments (e.g.,...
Eubacteria (“True Bacteria”) Characteristics: Rigid cell wall Flagellum (if motile) Cyanobacteria (Blue-Green Algae): Contain chlorophyll a (similar to plants) Photosynthetic autotrophs Forms: Unicellular, colonial, filamentous Habitats: Freshwater, marine, terrestrial Often form blooms in polluted water Some fix nitrogen in specialized cells called heterocysts (e.g., Nostoc, Anabaena) Chemosynthetic Autotrophs: Oxidize inorganic substances (nitrates, nitrites,...
Kingdom Monera Bacteria: Sole members of Kingdom Monera. Most abundant microorganisms on Earth. Ubiquitous (found almost everywhere): Soil Extreme habitats (hot springs, deserts, snow, deep oceans) On/in other organisms as parasites Bacterial Shapes: Coccus (cocci): Spherical Bacillus (bacilli): Rod-shaped Vibrium (vibrio): Comma-shaped Spirillum (spirilla): Spiral Characteristics: Simple structure, but...
Historical Perspective on Classification Primitive Classification: Early classification was instinctive and based on utility (food, shelter, clothing). Lacked scientific criteria. Aristotle’s Contribution: Used morphological characters for classification: Plants: Trees, shrubs, and herbs. Animals: Those with red blood and those without. Two-Kingdom System: Introduced by Linnaeus. Divided organisms into: Plantae:...
Rich Variety of Life: Millions of plants and animals have been identified and described. A large number of organisms remain unknown. Organisms vary in size, color, habitat, physiology, and morphology. Need for Classification: The diversity of organisms necessitates defining characteristics for study. Biologists have established rules and principles for:...
Overview of Taxonomic Categories Classification Process: Involves a hierarchy of steps, each representing a rank or category. All categories together form the taxonomic hierarchy. Each category is a taxon (plural: taxa) and represents a unit of classification. Key Features: Categories represent distinct biological entities, not just morphological groups. Knowledge...