features of an organism
1. “Features of an Organism”
In biology, features of an organism refer to the structural, physiological, and functional characteristics that determine:
The organism’s identity
Its mode of life
Its evolutionary relationships
Its position in biological classification
These features are inherited, observable, and measurable, and they arise due to genetic information and adaptation to the environment.
2. Structural Features
2.1 Presence or Absence of Vertebral Column
One of the most fundamental structural features is the vertebral column.
Vertebrates
Possess a vertebral column formed from vertebrae
Have a well-developed internal skeleton
Exhibit a dorsal nerve cord
Belong to Phylum Chordata
Examples: fish, amphibians, reptiles, birds, mammals
Invertebrates
Lack a vertebral column
May possess an exoskeleton or hydrostatic skeleton
Belong to various phyla such as Arthropoda, Mollusca, Annelida
Examples: insects, spiders, worms, snails
Biological significance:The vertebral column provides structural support, protection of the spinal cord, and allows advanced locomotion.
3. Physiological Features: Regulation of Body Temperature
3.1 Thermoregulation
Organisms are classified based on how they regulate body temperature.
Endothermic (Warm-blooded) Organisms
Maintain a constant internal body temperature
Heat is generated internally through metabolic processes
High energy demand
Groups:
Mammals
Birds
Ectothermic (Cold-blooded) Organisms
Body temperature varies with environmental temperature
Depend on external heat sources
Lower metabolic rate
Groups:
Fish
Amphibians
Reptiles
Biological significance:Thermoregulation influences habitat, activity patterns, and survival strategies.
4. Nutritional Features
4.1 Mode of Nutrition
Organisms are categorized based on how they obtain nutrients.
Autotrophic Nutrition
Organisms synthesize their own food using inorganic substances
Energy source is usually sunlight (photosynthesis)
Basis of all food chains
Examples: green plants, algae
Heterotrophic Nutrition
Organisms depend on other organisms for organic food
Includes herbivores, carnivores, omnivores, parasites, saprophytes
Examples: animals, fungi
5. Respiratory Features
Respiration is a biochemical process by which organisms release energy from food.
Types:
Aerobic respiration: requires oxygen, produces more energy
Anaerobic respiration: occurs without oxygen, produces less energy
Respiratory structures:
Lungs (mammals)
Gills (fish)
Tracheal system (insects)
Diffusion through body surface (simple organisms)
6. Reproductive Features
Reproduction ensures continuity of species.
Asexual Reproduction
Single parent
No fusion of gametes
Produces genetically identical offspring
Examples: binary fission, budding
Sexual Reproduction
Involves fusion of male and female gametes
Produces genetic variation
Important for evolution
Examples: humans, flowering plants
7. Habitat and Environmental Adaptations
Habitat refers to the natural environment in which an organism lives.
Types:
Terrestrial
Aquatic
Aerial
Amphibious
Organisms show structural and physiological adaptations suited to their habitat, such as:
Fins in aquatic animals
Lungs in terrestrial animals
Moist skin in amphibians
8. Locomotory and Movement Features
Movement is a defining characteristic of life.
Animals exhibit locomotion using specialized structures
Plants show growth and turgor movements
Movement allows:
Search for food
Escape from predators
Reproduction
9. Level of Organization
Organisms differ in complexity of organization.
Levels:
Cellular level
Tissue level
Organ level
Organ system level
Higher levels of organization indicate greater specialization and efficiency.