Biology Basics: Characteristics of Living Things

Study Notes

Organisms and Their Characteristics

An organism is defined as a living entity that contains one or more cells.
Five key characteristics define living organisms:
- Composed of cells, which are membrane-bound units.
- Capable of replication; they can make copies of themselves.
- Store, process, and exchange information, primarily via DNA and genes.
- Acquire resources and utilize energy for survival (e.g., plants converting sunlight).
- Evolve over time, leading to related species changing through generations.

Cell Definition and Importance

Cells are the simplest self-replicating units of life and can exist independently.
All living organisms are fundamentally made of cells.

Replication and Information

Replication refers to the ability of an organism to copy itself.
Information processing in living organisms involves storage, processing, and exchanging biological data.

Evolution

Evolution is described as "descent with modification," indicating that species are interconnected and can change over time.

Characteristics of Living Organisms

Living organisms are characterized by:
- Cellular structure
- Replication abilities
- Information handling
- Energy processing
- Evolutionary capacity

Living vs. Non-living Examples

Wine cork and dried beans (seeds) are considered living due to their cellular structure and other characteristics.
Viruses are classified as non-living because they require a host to replicate.

Fundamental Characteristics Misconception

The statement regarding giraffes having longer necks is not directly related to the five fundamental characteristics of life.

Origins of Organisms

All organisms are derived from cells, supported by two major theories:
- Cell Theory: All living organisms are made of cells, and all cells arise from pre-existing cells.
- Theory of Evolution: Explains the connection and changes among species over time.

Theories vs. Hypotheses

A theory is a well-supported body of ideas based on extensive empirical evidence, while a hypothesis is a testable statement that explains a phenomenon.

The Cell Theory

Formulated primarily by Robert Hooke, stating that:
- All living organisms consist of cells.
- All cells come from existing cells, disproving spontaneous generation.

Pasteur's Swan-Flask Experiment

Louis Pasteur's experiment tested the hypothesis that cells originate only from other cells.
The experiment involved sterilizing nutrient broth and using swan-neck flasks to prevent contamination.
Results showed no cell growth in the sterilized medium, reinforcing the notion that cells do not arise spontaneously and supporting the Cell Theory.

Description

This quiz explores the fundamental characteristics that define living organisms. It covers aspects such as cellular composition, replication, and the storage of genetic information. Ideal for students seeking to understand the basics of biology.