Characteristics of Life Quiz

Characteristics of Life

• Living organisms display unique characteristics distinguishing them from non-living entities.
• These characteristics include organization, metabolism, growth, adaptation, response to stimuli, reproduction, and homeostasis.
• Organization: Living structures range from atoms to molecules, cells, tissues, organs, organ systems, and organisms.
• Metabolism: Chemical reactions (anabolism and catabolism) support life functions, including energy acquisition and use.
• Growth: Organisms increase in size and complexity through cell division and material accumulation.
• Adaptation: Species evolve, adjusting to changing environments through natural selection. Favourable traits enhance survival and reproduction.
• Response to Stimuli: Organisms react to environmental changes, from plant phototropism to animal behaviours.
• Reproduction: Creation of similar organisms ensures species continuity, achieved through sexual or asexual methods.
• Homeostasis: Maintaining a stable internal environment (e.g., temperature, water balance) is crucial for survival.

Biological Organization

• Biological entities exhibit hierarchical order.
• Atoms combine into molecules, which form macromolecules, leading to organelles.
• These organelles work within the cell.
• Cell groups form tissues, tissues form organs, organs form organ systems, and these systems contribute to the organism.

Biodiversity

• Biodiversity encompasses the variety of life on Earth, encompassing genes, species, and ecosystems.
• Genetic diversity refers to the variations in genes within a species.
• Species diversity reflects the variety of species in an area.
• Ecosystem diversity includes the diverse habitats, communities, and ecological processes in a region.

Classification of Organisms

• Organisms are grouped based on shared traits, reflecting evolutionary links.
• The modern system classifies using evolutionary relationships.
• The hierarchical system (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species) organizes organisms based on shared history.

Cell Theory

• All life forms consist of cells or cell derivatives.
• The cell is the fundamental unit of structure and function in living organisms.
• All cells originate from pre-existing cells.

Types of Cells

• Prokaryotic cells: Lack a nucleus and membrane-bound organelles (e.g., bacteria, archaea).
• Eukaryotic cells: Contain a nucleus and membrane-bound organelles (e.g., animals, plants, fungi, protists).

Energy Flow in Ecosystems

• Organisms derive energy for survival from their environment.
• Food chains and webs depict energy flow within ecosystems.
• Producers (autotrophs) generate their own food through photosynthesis or chemosynthesis.
• Consumers (heterotrophs) obtain energy by consuming other organisms.
• Decomposers break down dead organisms, returning nutrients to the ecosystem.

Evolution

• Evolution is the inherited change in populations over generations, supported by fossil, anatomy, and genetic evidence.
• Natural selection is a driving force of evolution. Organisms with advantageous traits are more likely to survive and reproduce.

Ecology

• Ecology studies the interactions between organisms and their environment at various levels (populations, communities, ecosystems).
• Key concepts include population dynamics, community interactions, ecosystem processes, and biomes.
• Biomes are large-scale ecological communities defined by climate and the organisms adapted to it.