Chapter 1 - Biology and the Tree of Life Flashcards
Hypothesis
A testable statement to explain phenomenon or a set of observations.
What are the 5 characteristics of life?
Energy Cells Information Replication Evolution
Theory
An explanation for a very general class of phenomena or observations that are supported by a wide body of evidence.
Cell
A highly organized compartment that is bounded by a plasma membrane and contains concentrated chemicals in an aqueous solution.
2 Components of Scientific Theories
- Describes a pattern in the natural world
2. Identifies a mechanism or process that is responsible for creating the pattern
Cell Theory
All organisms are made of cells, all cells come from preexisting cells.
(Experimental) Prediction
Describes a measurable or observable result that must be correct if a hypothesis is valid.
Why was Pasteur’s set up effective?
He only changed one variable
Descent with modification
Characteristics of species can be modified from generation to generation
2 claims of evokution
- Species are related by common ancestry
2. decent with modification
Evolution
A change in the characteristics if a population over time.
Natural Selection Explains…
…how evolution occurs
2 Conditions of Natural Selection
- Individuals within a population vary in characteristics that are heritable
- In a particular environment, certain versions of these heritable traits help individuals survive better or reproduce more than other versions.
Heritable
Traits that can be passed on to offspring
Population
A group of individuals of the same species living in the same area at the same time
Natural Selection acts on:
Evolution Acts on:
Individuals
Populations
Artificial Selection
Humans select certain individuals to produce the most offspring
Evolution occurs when…
…heritable variation leads to differential success in reproduction
Fitness
The ability of an individual to produce offspring. More fit = More offspring
Adaptation
A trait that increases the fitness of an individual in a particular environment.
2 Unifying ideas of evolution and cell theory
- The cell is the fundamental structural unit in all organisms
- All species are related by common ancestry and have changed over time in response to natural selection
Speciation
The evolution of two or more distinct species from a single ancestral species.
Tree of life
A family tree of organisms
Phlogeny
The genealogical relationships between species
4 Letters for ribonucleotides
AUCG
LUCA
Last Universal Common Ancestor (of cells)
3 Types of Organisms
Bacteria, Archaea, and Eukarya
All Eukaryotes have:
A Nucleus
Most Prokaryotes do not have…
…a nucleus
Most prokaryotes have many/one cell(s).
One
Most eukaryote have many/one cell(s).
Many
Taxonomy
The effort to name and classify organisms
Taxon (plural taxa)
A named group of organisms
The three fundamental groups make up 3…
Domains
Phylum (plural phyla)
Major lines within a domain
Genus
A group of closely related species
Species
Evolutionarily independent population or group of populations.
Scientific name
an organisms genus and species
Why are experiments powerful scientific tools?
Experiments allow researchers to test the effect of a single, well-defined factor on a particular phenomenon
Null Hypothesis specifies
What should be observed when the hypothesis being tested isn’t correct.
