Principles of Biology Quiz

Principles of Biology

• Biology is the scientific study of living things and how they work
• Living things share characteristics that distinguish them from non-living things
• These characteristics include being composed of one or more cells, containing a genetic program, growing, reproducing, harvesting/transforming energy, responding to their surroundings, regulating internal environment, and evolving.
• Organisms possess all of these characteristics working together
• The parts of an organism function in concert to create emergent properties. Organism functionality is greater than the sum of its parts.
• Examples of these emergent properties include interactions among cells/tissues/organs and the overall emergent function of these systems

Levels of Biological Organization

• Biology is studied at many levels, from the submicroscopic level of molecules to the global scale of the entire living planet.
• Key levels of biological organization include: atoms, molecules, cells, tissues, organs, organisms, populations, communities, ecosystems, and biosphere.

Cells

• Cells are the basic units of life; all organisms are composed of cells.
• Cells can exist as independent, unicellular organisms or as subunits of multicellular organisms
• Cells exhibit characteristics required for life independently
• Cells have different types of organelles that perform specific tasks

Prokaryotes vs. Eukaryotes

• Prokaryotes are the oldest cell type, small, simple; lack a nucleus and organelles; single-celled.
• Eukaryotes evolved from prokaryotes; larger, more complex; contain a nucleus and organelles; single-celled or multicellular.

Life's Origins

• Life arose through chemical evolution (development from non-living to living).
• Self-replicating molecules were key in the origin of life
• Biological molecules then enclosed themselves within membranes.

The Central Dogma

• The central dogma describes the flow of genetic information in a cell.
• DNA transmits genetic information through transcription into RNA, and then translation into proteins. Key processes include transcription and translation.

Heritable Information (DNA)

• Biological instructions for ordering life processes are encoded in DNA (deoxyribonucleic acid)
• DNA is the substance of genes, the units of inheritance.
• DNA is passed on from parents to offspring during reproduction

Biodiversity

• Living organisms display remarkable diversity; there are many different types of life on Earth.
• Diversity is seen in variety of species, ecosystems, and genes.

Unity in Diversity

• Despite diversity, life exhibits striking unity, especially at lower levels.
• Characteristics of life include similar metabolic pathways, nearly universal genetic codes, and similarities in cell structure.

Evolution

• Evolution accounts for the combination of unity and diversity of life by describing change in the genetic makeup of organisms through time.
• Evolution happens through differential survival and reproduction.

Classification

• Taxonomic classification is a hierarchical system used to categorize organisms.
• Categorization occurs based on domain, kingdom, phylum, class, order, family, genus, and species levels.
• Scientists use the fossil record and molecular evidence to study and classify organisms.
• Phylogenetic trees illustrate evolutionary relationships and the order species diverged.