Lecture 6 Flashcards
Internal homeostasis
The tendency to maintain a stable, relatively constant internal environment
External stimuli
A change in the environment external to the organism
Heredity
the passing on of physical or mental characteristics genetically from one generation to another
Adenosine triphosphate (ATP)
Unit of energy in cells, produced by electrochemical gradients
Last universal common ancestor
Evidence from modern-day life suggests that all current life evolved from a single common ancestor
Carbon-based
carbon atoms, bonded to other carbon atoms or other elements, form the fundamental components of many, if not most, of the molecules found uniquely in living things
Conformations
the shape (or spatial arrangement of atoms) that is formed by a molecule that is caused by the rotation around one or more single bonds
Primordial soup theory
Proposed “early earth” environment consisting of high concentrations of compounds and elements known to be abundant in life
-carbon
-hydrogen
-water vapor
-ammonia
RNA world theory
RNA formed first, proliferation of RNA eventually lead to DNA and protein formation
Hydrothermal deep sea vent theory
Involves the generation of electrochemical gradients and metal-containing enzymes as the first precursors to life (allowed for the generation of energy)
Fossilization
- organism dies 2. natural decomposition is delayed 3. organic molecules in dead organism gradually replaced by minerals
Molecular clock
Technique that estimates the divergence of 2 species by calculating and comparing the mutation rates in DNA over time
Stromatolites
Colonies of bacteria, primitive photo-synthesizers (need to grow in shallow seas)
Aerobic
Requiring the presence of air or free oxygen for life
Anerobic
Without oxygen
