TBR 1 - Core concepts in biology Flashcards
What is the study of biology?
- The science of life/living
- A point of convergence for the info and tools from all natural sciences
What does the study of biology not reveal?
No new laws of nature - just how existing laws work
What allows the complexity of living systems?
Sun’s constant energy -> organic molecules by photosynthesis
What 2 sciences underly the workings of biology?
- Chemistry for the chemical workings of cells
- Physics for thermodynamics and energy conversion
Why is biology the focus of the multidisciplinary approach to science?
Biological problems require multiple different approaches to get solutions
List the 7 characteristics of living systems
- Cellular organisation
- Ordered complexity
- Sensitivity = stimuli
- Growth, dvlpmt, reproduction
- Energy utilisation
- Homeostasis
- Evolutionary adaptation
Describe the cellular level of hierachical organisation
- Atoms to molecules to organelles in cells
- Cell as basic unit of life
Describe the 3 levels of organismal level of hierarchical organisation
- Tissues = similar cells in functional unit
- Organs = different tissues in structural and functional unit
- Organ systems = different organs
Describe the 3 levels of populational level of hierarchical organisation
- Population = same species and space
- Species = interbreed and similar appearance
- Community = populations of different species in same place
Describe the ecosystem level of hierarchical organisation
Populations x environment = ecosystem
Describe the biosphere level of hierarchical organisation
Entire planet as 1 big ecosystem
What are emergent properties in hierarchical organisation?
- Novel properties from the way components interact and can’t be found by studying individual components
- Eg studying 1 cell doesn’t tell you about whole organism
What is science concerned with?
Developing an increasingly accurate understanding of the world using observation and reasoning
What is deductive reasoning - definition, what does it test, how?
- Use of general principles to predict a specific result
- Tests validity
- Uses maths and philosophy
What is inductive reasoning- definition, what does it test?
- Use of specific observations to make a generalization
- Tests hypotheses
What is a hypothesis?
- Suggested explanation for observations
- Testable predictions
- Subject to future rejection by new info
What is a control group used for?
Keeping variable of interest constant to compare to changed/experimental variable
What is reductionism and its issues in biology?
- Understanding a complex system by reducing it to working parts eg biochem
- Emergent properties and enzymes etc might not behave the same in isolation
Why do scientists used models?
- Organise problem
- Away from extreme reductionism
- Apply isolated knowledge in cellular context
What are the 2 definitions of ‘theory’ in science?
- Proposed explanation for natural phenomenon
- Concepts supported by reasoning and evidence
Compare basic vs applied research
- Basic = extend what we know
- Applied = putting basic research in industrial context
Explain the 1st core concept of biology - life subject to chemical and physical laws
- Biological systems = complex chemistry
- No new laws just application of existing
- Relevant to all biology not just cells and molecules
Explain the 2nd core concept of biology - structure determines function
- Know the function = infer function of similar structures elsewhere
- Alter structure = disrupt function = potential physiological consequences
Explain the 3rd core concept of biology - living systems transform energy and matter
- Original source from sun
- Photosynthesis makes organics for others to use
- Constant energy = non-equilibrium = complex self-organisation
Explain the 4th core concept of biology - living systems depend on info transactions
- DNA = genome, heredity, synthesis, protein folding, gene expression
- Signal transduction = change behaviour, morphology, physiology
Explain the 5th core concept of biology - evolution explains unity and diversity
- 3.5 BYA origin of life with some features preserved
- Conserved = fundamental
- Unity = shared conserved features
- Diversity = evolutionary change
Define sympatric
Differentiation (phenotype) of populations into species in same area
Describe the phenotypical variation patterns noted in populations in different areas and how they result
- Distant populations distinct but connected by in-between populations with intermediate phenotype
- Due to gene flow
Define the biological species concept and causes reproductive isolation
- Groups of interbreeding populations reproductively isolated from other groups
- Not in contact or can interbreed but choose not to
What is the 1st law of thermodynamics and what form of energy is a one-way conversion?
- Energy can’t be created or destroyed - only change forms
- Heat is one-way
What forms of energy do plants and animals need and what form do they release?
- Animals need chemical energy, plants need light
- Both lose energy as heat = radiation
What is the productivity of a trophic level?
Rate at which organisms in the level collectively make new organics
What is cross primary productivity (GPP) and net primary productivity (NPP)?
- GPP = raw rate of primary producers making new organics
- NPP = GPP minus respiration of primary producers = organics available for herbivores
How much solar energy is captured vs how much becomes heat?
1% captured, 99% heat
Where is energy lost as it’s passed between trophic levels (3 possibilities)?
- Chemical bond energy in faeces
- Converted to heat during cellular processes
- Herbivores die of disease/accident instead of eaten
Define trophic cascade/top-down effects and when they occur
- Effects in upper trophic level influence 2+ lower levels
- Changes in top level affects primary producers
When do bottom-up effects occur?
Changes to primary producers affect higher trophic levels ie increased primary production
