Exam 1: Fundamental theories of biology Flashcards
What three theories form the framework for modern biological science?
- The cell theory
- The theory of evolution by natural selection
- The chromosome theory of inheritance
What are the two components of the cell theory?
- All organisms are made of cells
- All cells come from pre-existing cells
What is the difference between a hypothesis versus a prediction?
A prediction says what will happen in an experiment if the hypothesis is correct. A hypothesis is a broader idea.
Explain Louis Pasteur’s experiment.
Two flasks were used that differed in stem shape: straight and swan necked. Both flasks had broth and were boiled for identical times to kill organisms. After sterilization, only microorganisms were found in the straight necked flask, which corroborated the all-cells-from-cells hypothesis.
How did the first cells arise?
Chemical evolution
What is a species?
A distinct, identifiable type of organism
What is evolution?
A change in the characteristics of a population over time
What is a population?
A group of individuals of the same species living in the same area at the same time
What are the two conditions for natural selection?
- Individuals must vary in characteristics that are heritable
- Versions of these heritable traits must help individuals reproduce more than other versions
Natural selection acts on _____. Evolution occurs in _______.
Individuals, populations
When does speciation occur?
When populations diverge to form new species
What is the tree of life?
A family tree of organisms that shows the relationships among species
What is phylogeny?
The genealogical relationships among all organisms
What is our first common ancestor?
LUCA (Last universal common ancestor)
What is vertical descent with modification?
Progression of changes in a lineage
