Chapter 1: The Science Of Bio Flashcards
Bio unified what?
Much of natural science
Living systems are the most complex what?
Chemical systems on earth
Life is constrained by?
The properties of chem. and physics
Science is becoming?
More interdisciplinary (combining multiple fields)
7 characteristics of all living organisms:
- Composed of cells
- Complex and ordered
- Respond to their environment
- Can grow, develop, and reproduce
- Obtain and use energy
- Maintain internal balance
- Allow for evolutionary adaption
Cellular level:
Atoms, molecule, macromolecule, organelle, cell
Organism level:
Tissue, organ, organ system, organism
Population level:
Species, population (of one species), community (multiple species), ecosystem (including living environment), biosphere
Each level has emergent properties
- result from interaction of components
- cannot be deduced by looking at parts themselves
- “life” is an emergent property
Science aims to understand?
The natural world through observation and reasoning
Science begins with? Meaning what?
Observations. So much if science is purely descriptive
- classification of all life on earth
- human genome sequencing
Science uses both?
Deductive and inductive reasoning
What is deductive reasoning?
Uses general principles to make specific predictions
What is inductive reasoning?
Uses specific observations to develop general conclusions
Scientists use a systematic approach to?
Gain understanding of the natural world known as the scientific method
Scientific method steps?
- Observation
- Hypothesis formation
- Prediction
- Experimentation
- Conclusion
A hypothesis is a possible?
Explanation for an observation
A hypothesis
Must be tested to determine validity
Is often tested many diff. ways
Allows for predictions to be made
Iterative (repeating process to generate a sequence of outcomes trying to reach a specific one)
Hypotheses can be changed and refined with new data
Experiments:
- Test hypothesis
- Must be carefully designed to test only one variable at a time
- Consists of a test experiment and a control experiment
Predictions:
Hypotheses should make predictions
Predictions provide a way to test the validity of hypotheses
Hypothesis must be rejected if the experiment produces results inconsistent with the predictions
The more experimentally supported predictions a hypothesis makes, the more valid the hypothesis
Spontaneous generation?
Not true. Preexisting microorganisms
Two philosophical approaches to science:
Reductionism / systems biology
Reductionism?
To break down a complex process down to its simpler parts
Systems biology?
Focus on emergent properties that can’t be understood by looking st simpler parts
Models in science:
- ways to organize thought
- parts provided by reductionist approach
- model shows how they fit together
- suggest experiments to test the model
Scientific theory:
Is a body of interconnected concepts
Is supported by much experimental evidence and scientific reasoning
Expresses ideas of which we are most certain
Compare to general meaning of theory:
Implies a lack of knowledge or a guess
Basis research intended to?
Extend the boundaries of what we know
Applied research:
Foundation provided by basic research
May involve the manufacture of food additives or drugs
Unifying themes in bio:
- Cell theory
- Molecular basis of inheritance
- Structure and function
- Diversity of life arises by evolution
- evolutionary conservation
- cells are info-processing systems
- nonequilibrium state
Cell theory:
- all organisms are composed of cells
- cells are life’s basic units
- all cells come from preexisting cells
Molecular basis of inheritance:
- deoxyribonucleic acid (DNA)
- sequence of 4 nucleotides encode cell’s info
- gene- discrete unit of info
- genome- entire set of DNA instructions
- continuity of life depends on faithful copying of DNA into daughter cells
Structure and function:
- you study structure to learn function
- know a function- look for that structure in other organisms
- ex: *receptor on human cell for insulin unknown
* find similar molecule in worm
* might conclude this molecule functions the same in the word
Diversity of life arises by?
Evolution
3 domains
Bacteria- single cell prokaryote
Archaea- single-cells prokaryote
Eukarya- single-called or multicellular eukaryote
Evolution diversity bc?
Bio-chem and genetics argues for life from the same origin point
Diversity bc evolutionary changes over time
Evolutionary conservation
All organisms today descended from a simple creature 3.5 BYA
Some characteristics preserved- use of DNA
Conservation reflects that they have a fundamental role
Cells are info-processing systems:
Info in DNA used to direct synthesis of cellular components
Cells process environmental info
Cells in multicellular organisms must coordinate with each other
Nonequlibrium state
Living systems= opened systems
Constant supply of energy needed
Self-organizing properties at different levels
Emergent properties from collections of molecules, cells, and individual
Darwin and Evolution shows?
Ex of how scientist develops hypothesis and how a theory gains acceptance
Darwin published?
The Origin of species after 30 years observation
Darwin was a?
Naturalist mapping coastal South America
Darwin wasn’t the first to?
Propose evolution
Darwin’s contribution was a
Mechanism (natural science)
Darwin said characteristics of similar species…
Varied from place to place
Galapagos Finches (bird) 14 species differed only slightly
“Descent with modification” or evolution
Populations of plants and animals do what?
Increase geometrically
Humans can only do what?
Increase their food supply arithmetically
Populations of species remain constant bc
Death limits population #’s
Evidence supporting Darwin’s theory has grown bc?
Fossil record
Earth’s age
Mechanism for heredity
Kendal’s laws of inheritance unknown to Darwin
Comparative anatomy
Vertebrae forelimbs all share same basic array of bones
Homologous- same evolutionary origin not now differ in structure and function
Analogous- structures of different origin used for same purpose (butterfly and bird wings)
Molecular evidence:
Compare genomes of proteins if different organisms
Phylogenetic trees- based on reacting origin of particular nucletide changes to reconstruct an evolutionary history
