Chapter 1.1: Living Organisms Share Common Aspects of Structure, Function, and Energy Flow

Flashcards from Chapter 1.1 of Principles of Life, 3rd Edition.

Biology

The study of life in order to understand the interactions between organisms in the natural world

Organisms

In biology, all living things, deriving from a single common ancestor on Earth

Shared characteristics

Evidence for the common ancestry of life; includes:

• Nucleic and amino acids, for genetic code and proteins

• Membrane-enclosed cells with different parts

• Molecular conversions for energy and replication

• Evolution

Diversity

The many variations of lifeforms on Earth created through evolution and studied in biology

Life

The state of living; can be debated what characteristics exactly comprise this on Earth (like with viruses)

4.6 bya

The time of the formation of the earth

4 bya

When life first appeared on Earth, aided by its early composition of complex organic molecules

500 kya

When the first modern humans arose

Nucleic acids

Molecules that can self-reproduce and contain instructions for the synthesis of other molecules, like proteins

Proteins

Large, complex molecules with varying shapes that interact with other molecules

Cell

A membrane-enclosed environment created by fatty acids to prevent dissolution in water

• Enabled the concentration and control of chemical reactions, allowing for reproduction later on

Prokaryotes

Single-celled organisms containing genetic material and other simpler structures

• Initially only lived in the ocean for UV light protection without ozone, taking in and breaking down molecules for energy

Photosynthesis

A set of chemical reactions transforming solar energy into chemical-bond energy in glucose and other molecules in the cell

• Enables the life of plants and other dependent organisms

• Likely arose from prokaryotes similar to today’s cyanobacteria

Oxygen (O₂)

The byproduct of photosynthesis; creation of this early on allowed for aerobic respiration and life on land with ozone

Aerobic metabolism

A set of chemical reactions that releases energy from life’s molecules using O₂ in a much more efficient manner

Anaerobic metabolism

A set of reactions that extracts energy without using O₂

Ozone (O₃)

What shields the earth from UV rays and enabled life on land

Organelles

Membrane-enclosed compartments that can perform specialized cell operations

2.5 bya

When the first organelles appeared in cells on Earth and when photosynthesis first arose

Nucleus

An organelle containing the cell’s genetic information

Endosymbiosis

When a cell lives inside another cell; it is hypothesized that this enabled the creation of mitochondria and chloroplasts in order to provide sugar or an environment for each other

Cellular specialization

The process of cells becoming more efficient in certain functions during the rise of multicellular organisms

Genome

The sum total of an organism’s genetic material

Mutations

Changes in a genome during every replication; these can build up over time to create a new species

Binomial

The term for the scientific names of animals, these are all italicized and made up of two Latinized words

Phylogenetic tree

What can be created as a result of knowing an organism’s ancestry and evolutionary relationships

Bacteria

Unicellular organisms lacking a nucleus but containing ribosomes, peptidoglycan in the cell wall, and genetic information

Archaea

Unicellular organisms lacking a nucleus as well as peptidoglycan in the cell wall; cells specialized out of these to later form nuclei

Eukarya (eukaryotes)

Cells that contain a nucleus and other structures that form one of the three domains of life; many are multicellular

Model systems

Certain species used for the study and generalization of biological knowledge