A2.1 HL only Flashcards
Prebiotic age
hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago
Proto-Earth
encompassing Earth in its first one billion years
Extraplanetary objects
an astronomical object that exists outside the Solar System.
Hadean Eon
the oldest eon and dates from 4.5–4.0 billion years ago. This time represents Earth’s earliest history, during which the planet was characterized by a partially molten surface, volcanism, and asteroid impacts
inorganic molecules
Inorganic molecules are generally simple and are not normally found in living things. Although all organic substances contain carbon , some substances containing carbon, such as diamonds, are considered inorganic
organic molecules
a complex molecule that is primarily made of carbon atoms bonded with other elements and/or other carbon atoms. All living things on Earth are composed of organic molecules
unicellular
composed of a single cell
multicellular
an organism that is made of many cells, such as plants, animals or fungi
organelles
a subcellular structure that has one or more specific jobs to perform in the cell
compartmentalization
the separation of the cell interior in distinct compartments with specific local conditions that allow the simultaneous occurrence of diverse metabolic reactions and processes
Subcellular components
specific structures that take on sets of tasks within the cell, or they can be local regions of the cell defined by the concentration of molecules or distinct physical characteristics and proportions
binary fission
the process of one cell simply dividing into two. It is most commonly used in archaea and bacteria, which are both prokaryotic organisms
mitosis
the process by which a cell replicates its chromosomes and then segregates them, producing two identical nuclei in preparation for cell division.
gametes
a reproductive cell of an animal or plant. In animals, female gametes are called ova or egg cells, and male gametes are called sperm
paradox
contradictory-yet-interrelated elements that exist simultaneously and persist over time
proto-cell
self-organized, endogenously ordered, spherical collection of lipidsproposed as a rudimentary precursor to cells
Spontaneous generation theory
hypothetical process by which living organisms develop from nonliving matter
LUCA
the hypothesized common ancestral cell from which thethree domains of life, the Bacteria, the Archaea, and the Eukarya originated
Primordial Soup Theory
if energy is added to the gases that made up Earth’s early atmosphere, the building blocks of life would be created
Polymerization
any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer
Miller-Urey experiment
experimentalsimulationconducted in 1953 that attempted to replicate the conditions ofEarth’s earlyatmosphereandoceansto test whetherorganicmoleculescould be created abiogenically, that is, formed fromchemical reactionsoccurring betweeninorganicmolecules thought to be present at the time