Characteristics of Life

Characteristics of Life

• Living organisms are composed of cells, which are the basic structural and functional units of life (e.g., human cheek cells, plant leaf cells, bacteria E. coli cells)

Order

• Living organisms exhibit order, which is reflected in the highly organized structures of their cells, tissues, organs, and organ systems
• Examples of order include the presence of cilia on the surface of a single-celled paramecium and the identical internal order of cilia in a human trachea, as well as the pattern of a sunflower

Adaptations

• In a population, individuals with favorable traits have a higher survival and reproduction rate
• Adaptations can result in modified structures, such as the leaves of a cactus that have evolved into sharp spines to protect the plant from predators

Response to Environment

• Living organisms can respond to changes in their environment, known as stimuli
• Examples of responses to stimuli include a Venus fly trap closing on a fly that triggers the trap and sunflowers moving to face the sun as it travels across the sky

Regulation/Homeostasis

• Living organisms maintain a specific range of internal conditions despite external changes
• Examples of regulation/homeostasis include dogs and chickens panting to cool down when they are too hot

Reproduction

• All living organisms can reproduce, passing their genes (DNA/RNA) to healthy, fertile offspring
• Examples of reproduction include a turtle laying eggs that hatch into baby turtles

Energy Processing

• Living organisms require a source of energy, which can come from photosynthesis or consuming other organisms
• An example of energy processing is a caterpillar eating a leaf to obtain energy

Growth and Development

• Organisms grow and develop in a specific sequence based on the instructions in their genes
• An example of growth and development is a frog egg hatching into a tadpole, which eventually metamorphoses into a frog