Lecture 1: Intro to evolution + The cell theory Flashcards
All organisms share ___.
5 fundamental characteristics
Fundamental characteristic #1: All organisms are made up of membrane-bound cells
Cells
Fundamental characteristic #2: All organisms are capable of reproduction
Replication
Fundamental characteristic #3: Population of organisms are continually evolving
Evolution
Fundamental characteristic #4: All organisms process hereditary info encoded in genes as well as info from the environment
Information
Fundamental concept #5: All organisms acquire and use energy
Energy
How many theories form the framework for modern biological science?
3 theories
What is a theory? (3 points)
- Explanation for a broad class of phenomena or observations
- Supported by a wide body of evidence
- Differs from “speculation” or “guess”
What does “the cell theory” explain?
What are organisms made of?
What does “the theory of evolutions by natural selection” explain?
Where do organisms come from?
What does “the chromosome theory of inheritance” explain?
How is hereditary info transmitted from one generation to the next?
CELL THEORY: who were the first to observe cells in the late 1600s?
Robert Hooke + Anton van Leeuwenhoek
What is a cell? (3 points)
- Highly organized compartment
- Bounded by plasma membrane
- Contain concentrated chemicals in aqueous solution
The cell theory states that
- All organisms are made of cells
- All cells come from preexisting cells
The smallest cell (200nm) is? MG
Mycoplasma gallisepticum (5000 could fit side-by-side within one mm)
The largest cell is (2,384 acres) AO
Armillaria ostoyae (About 9.5 x larger than McMaster’s entire campus (~300 acres)
What is a hypothesis?
- A TESTABLE statement that explains something observed
- An EXPERIMENT allows researchers to test the effect of a factor on a particular phenomenon
- a PREDICTION is a measurable/observable result that must be correct if a hypothesis is valid
Hypothesis =/ Prediction: T OR F?
True
What is hypothesis? (in terms of x+y)
X- explanatory/independent variable)
affects/predicts
Y- response/dependent variable
Does NOT IMPLY direction
What is predicton? (in terms of x+y)
X- explanatory/independent variable
increases/decreases
Y- response/dependent variable
IMPLIES direction
Where do cells come from (2 competing hyptheses)
- Spontaneous generation
- Cell theory
Hypothesis #1 is:
- Prevailing paradigm until mid 1800’s
- Organisms could arise spontaneously under certain conditions
- Bacteria + fungi that spoils food (milk + wine)
-> springing to life from nonliving materials
Spontaneous generation
Hypothesis #2 is:
- All organisms are made of cells and all cells come from preexisting cells
Cell theory
Louis Pasteur’s hypothesis? (2 points)
- Cells arise from cells
- Cells do not arise by spontaneous generation
Louis Pasteur’s? (in terms of x+y)
X = presence of preexisting cells
Y = cells arise (i.e., cell growth)
What is “the presence of preexisting cells affects cell growth” an example of?
Hypothesis
What is “The presence of preexisting cells does not affect cell growth” an example of?
Null Hypothesis
What is “Preexisting cells are required for cell growth to occur” and “Cells will not grow in the absence of preexisting cells” an example of?
Predictions
What experiment does this occur:
- Nutrient broth in straight necked flask
- Boil to sterilize flask killing living cells
- Pre exisiting cells enter flask from air
Pasteur experiment w/ straight necked flasks (All-Cells-from-Cells Hypotheses tested)
What experiement does this occur:
- Place nutrient broth in swan-necked flask
- Boil to sterilize flask killing living cells
- Preexisiting cells from air are trapped in swan neck
Pasteur experiment w/ swan-necked flasks (Spontaneous Hypotheses tested)
