Chapter 1: Characteristics of Life and Levels of Organization

Vocabulary flashcards covering key terms and definitions from Chapter 1 on the Characteristics of Life and Levels of Biological Organization.

Biology

The study of living organisms and their interactions with one another and their environments.

Organisation

A characteristic of life defined by highly structured internal and external physical states.

Sensitivity

The characteristic of life involving the detection of and rapid response to diverse internal and external stimuli.

Reproduction & Growth

The characteristic of life encompassing changes in life cycle, bodily expansion, and genetic replication.

Regulation & Homeostasis

The characteristic of life responsible for maintaining internal physiological equilibrium despite external chaos.

Adaptation

The ability of living organisms to fit their environment over generations as a consequence of evolution by natural selection.

Energy Processing

The characteristic of life involving the capturing and utilising of metabolic energy to fuel biological activity.

Cell

The absolute smallest fundamental unit of structure and function in living organisms that exhibits all the characteristics of life.

Unicellular Organisms

Single-celled entities (e.g., Paramecium, Amoeba, Mycobacterium) that are functionally independent.

Multicellular Organisms

Many-celled entities (e.g., Bison/calf, Human) in which cells become highly specialized to perform distinct, complex specific functions.

Stimulus

A specific form of energy (light, heat, chemical) that triggers a biological detection process.

Receptor

Sense organs that detect stimuli.

Sensation

The internal ability of an organism to receive and detect a stimulus.

Response

The physical, observable reaction of an organism to a stimulus.

Taxis

Directional movement of an organism toward (positive) or away from (negative) a stimulus.

Chemotaxis

Directional movement in response to chemical stimuli, such as bacteria reacting to chemicals.

Phototaxis

Directional movement in response to light, such as plants bending toward light.

Development

Encompasses all structural changes a body undergoes in life, driven by differentiation.

Differentiation

The critical process where unspecialized cells become specialized in both structure and function.

Growth

An increase in total body size achieved by increasing the number of existing cells, increasing the size of existing cells, or increasing the amount of non-cellular material.

Asexual Reproduction

Reproduction in single-celled organisms consisting of simple division into two new cells.

Sexual Reproduction

Reproduction in multicellular organisms involving the formation of specialized reproductive cells called gametes that fuse to form new individuals.

Gametes

Specialized reproductive cells formed by multicellular organisms during sexual reproduction.

Homeostasis

The steady state ability of living organisms to maintain constant internal conditions (such as body temperature at $37^{\circ}\text{C}$) despite short-term environmental changes.

Metabolic Pathway

A series of chemical reactions that takes a starting molecule and modifies it to yield a final product, usually using an enzyme catalyst.

Anabolic Pathway

A metabolic synthesis pathway that builds complex polymers from smaller monomers and requires energy input.

Catabolic Pathway

A metabolic degradation pathway that breaks down complex polymers into their monomers, producing or releasing energy.

Photosynthesis Equation

The fundamental plant equation: $\text{Sun Energy} + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{Glucose} + \text{O}_2$

Aerobic Cellular Respiration Equation

The fundamental animal equation: $\text{Glucose} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} + \text{ATP (Energy)}$

Atom

The smallest and fundamental unit of matter.

Molecule

A chemical structure consisting of at least two atoms held together by a chemical bond.

Macromolecules

Large molecules typically formed by combining smaller units called monomers into polymers.

Organelles

Small, specialized structures functioning within cells.

Prokaryotes

Organisms with simple cell architecture that lack membrane-bound organelles and nuclei.

Eukaryotes

Organisms with complex cell architecture containing membrane-bound organelles and a defined nucleus.

Tissue

A group of similar cells carrying out the same function.

Organ

A collection of tissues grouped together based on a common function.

Organ-System

A higher level of organization consisting of functionally related organs working together.

Organism

The individual living entity combining all systems.

Population

All individuals of the same species living within a specific area.

Community

A set of different populations inhabiting a particular area.

Ecosystem

All living things in a specific area interacting with the abiotic/nonliving parts.

Biosphere

The collection of all ecosystems, zones of life on Earth.