Practice Quiz: Characteristics of Life

Photosynthesis is not a universal characteristic because only certain organisms, such as plants, algae, and some bacteria, perform it. All other living organisms do not rely on photosynthesis as a defining trait.

Cells are the fundamental building blocks of all living organisms. Each cell is a self-contained unit capable of performing all the functions necessary for life.

Homeostasis is the mechanism by which organisms regulate their internal environment to maintain a stable, constant condition. This regulation is essential for survival regardless of external changes.

Metabolism encompasses all the chemical reactions involved in maintaining the living state of cells and organisms. These processes are necessary for converting food to energy, building cellular structures, and eliminating waste.

Reproduction is the process by which living organisms produce new individuals, ensuring the continuity of the species. This biological function allows for the transfer of genetic material from one generation to the next.

Cellular organization is a defining feature of all living organisms, as every living thing is composed of one or more cells. Non-living objects lack this complex and organized structure.

Enzymes function as catalysts that accelerate chemical reactions within cells. This acceleration is critical for efficient metabolism and the ability of cells to perform necessary functions quickly.

Maintaining homeostasis involves responding appropriately to environmental changes to keep internal conditions stable. This regulated response is essential to ensure that vital functions can proceed even when external conditions vary.

Cell theory is a fundamental concept in biology that asserts every living organism is composed of cells. This principle emphasizes the importance of cells as the basic unit of life.

Photosynthesis is the process by which plants capture sunlight and convert it into chemical energy stored in glucose. This conversion is foundational to the energy flow in most ecosystems.

Growth in living organisms typically occurs through an increase in the number of cells produced by cell division. This increase in cell number results in the development and enlargement of the organism.

Adaptation enables organisms to cope with changes in their environment, thereby improving their chances of survival. Over time, beneficial adaptations can lead to evolutionary changes within populations.

Reproduction is essential for transferring genetic material to the next generation, which introduces genetic diversity. This diversity is a key factor in natural selection and helps populations adapt over time.

Cellular respiration is the process that converts glucose into ATP, the energy currency used by cells. This conversion is crucial for powering the various functions necessary for life.

The mitochondrion is known as the powerhouse of the cell because it generates ATP through cellular respiration. Its role in energy production is vital for nearly all cellular activities.

Homeostasis involves internal regulation to maintain a stable state in response to external conditions. Shivering in humans is a direct example of a physiological response that generates heat to maintain a constant body temperature.

Mutations are changes in the DNA that can produce genetic variations within a population. These variations serve as the raw material for natural selection and are fundamental to the process of evolution.

Cellular respiration breaks down glucose to release energy, which is then used to produce ATP, the energy currency of cells. This process is critical for meeting the energy demands of living organisms.

DNA contains the genetic instructions necessary for the development and functioning of all living organisms. It is the blueprint that governs cell structure, function, and reproduction.

Photosynthesis produces oxygen as a byproduct, which is essential for cellular respiration in most organisms. This interdependent relationship creates a balanced cycle that supports energy production throughout ecosystems.