1.1, 1.2- Jan 9 Flashcards
Jan 9 Lecture
What are the five fundamental characteristics that all living organisms share?
Cells
Evolution
Energy
Replication
Information
Describe the characteristic of “cells” in a living organism
All organisms are made of membrane bound cells
Describe the characteristic of “replication” in living organisms
All organisms are capable of reproduction
Describe the characteristic of “evolution” in living organisms
Populations of organism are continually evolving
Describe the characteristic of “information” in living organisms
All organisms process hereditary information encoded in genes as well as information from the environment
Describe the characteristic of “energy” in living organisms
All organisms acquire and use energy
What is a theory?
An explanation for a broad class of phenomena or observations
- supported by a wide body of evidence
How is the scientific word for theory different than the modern use?
Modern use attaches it to “speculation” or “guess”
How is a theory different than a conspiracy theory?
Conspiracy theory is not supported by a wide body of evidence
What are the three theories for modern biological science?
- the cell theory
- the theory if evolution by natural selection
- the chromosome theory of inheritance
What question does the cell theory focus on?
What are organisms made of?
What question does the theory of evolution by natural selection answer?
Where do organisms come from?
What question does the chromosome theory of inheritance answer?
How is hereditary information transmitted from one generation to the next?
Who were the first to observe cells in the late 1660’s?
Hooke and Leeuwenhoek
Define cell
A highly organized compartment
- bounded by plasma membrane
- containing concentrated chemicals in an aqueous solution
What does the cell theory state
- all organisms are made of cells
- all cells come from pre-existing cells
What is the smallest living organism?
Mycoplasma gallisepticum (200 nm)
- bacterium, causes diseases in chickens and other bird species
What is the largest living organism?
Armillaria ostoyae (2,284 acres)
- humongous fungus
- causes root disease in conifer species
Define hypothesis
A testable statement that explains something observed
Define experiment
Allows researchers to test the effect of a factor on a particular phenomenon
Define prediction
A measurable or observable result that must be correct if a hypothesis is valid
How is a hypothesis different than a prediction?
Hypothesis: x affects y
* does not imply direction
Prediction: x increases/ decreases y
* does imply direction
What are the two competing hypotheses about where cells come from?
- spontaneous generation
- cell theory
What is the spontaneous generation
Organisms could arise spontaneously under certain conditions
- bacteria and fungi that spoil food such as milk and wine
- springing to life from nonliving materials
What is the cell theory
All organisms are made of cells and all cells come from preexisting cells
What is Louis Pasteur’s hypothesis
- cells arise from cells
- cells do not arise by spontaneous generation
“ the presence of preexisting cells affects cell growth”
How were the cell and spontaneous generation hypotheses tested?
- Nutrient broth was placed in a straight necked and swan necked flask and boiled
- all living cells in the flask were killed
- The condensation settled in the neck of the swan flask
- Preexisting cells entered in the straight neck flask
- Preexisting cells from air are trapped in the swan neck
