Week One Flashcards
Characteristics of living organisms
Common set of chemical components and similar structures Interact with environment Contain genetic info Convert external molecules Extract energy from environment Replicate Evolve through gradual change
3 domains
Archae
Bacteria
Eukaryotes
Human makeup
Atoms Small molecules Large molecules, proteins and nuclei acid DNA Cells Cell specialisation Tissue Organ Organ systems Mutlicellular organisms
Theory of evolution
Organisms change over time as a result of changes in heritable physical and behavioural traits to better adapt to their environment
Natural selection
Leads to adaptions, structural, physical or behavioural traits that enhance survival
Second law of thermodynamics
Left by themselves, organised entities tend to become more random
Energy is required for cells to combat tendency for their structures to lose organisation
DNA
Made up of 2 strands of linked sequences of nucleotides
4 nucleotides - C,G,A,T
Gene
Consists of specific sequence
Contains info for making certain protein
Proteins
Govern chemical reactions
Endosymbiosis
Larger cells engulfing small cells
Cellular specialisation
Become specialised to perform certain functions
Mutations
Happens when genome is replicated
Mutation effect
Gives rise to structural and functio changes
Alters nucleotide sequence as well as proteins
Harmful or no effect, but may improve organism function
Positive feedback
Destabilises the system
Negative feedback
Stabilises a system
Formation of nuclei acids
Reproduced and contain information to produce proteins
Organisms start
Started as unicellular prokaryotes confined to ocean to be protected by uv light
Lack of o2
No protective 03 layer
Photosynthesis evolution
O2 was a by product and harmful to most prokaryotes
Organisms that tolerated o2 evolved aerobic metabolism and grew larger
O2 produced layer of ozone which absorbed harmful uv and organisms move from sea to land
Proximate explanations
Immediate genetic, physiological, neurological and developmental processes that explain how adaption works
Ultimate explanations
Processes that led to the evolution of an adaption
Theory
Body of scientific work which is tested and well established facts and principles are used to make predictions
Scientific method
Observations Questions Hypotheses Predictions Testing
Controlled experiments
Manipulate factors
Independent variables
The variable being measured
Dependent variable
The response that is measured
Comparative experiments
Difference between samples and groups, variables not controlled
Evolution of cells
4.5 billion years ago cell nuclei is made Cell membranes are formed Prokaryotes develop Endosymbiosis Eukaryotes Eukaryotes don't seperate Cell specialise
Binomial naming
Genus then species
Hierarchy of life
Atoms Molecules Cells Cell specialisation Tissues Organs Organ systems Population Community Landscape Biosphere
Endosymbiosis Theory
Theory that eukaryotic cells evolved via the engulfing of one prokaryotic cell by another
Nucleic Acid
Polymer made of nucleotides, specialised for storage, transmission and expression of genetic info
Null hypothesis
The premise that any differences observed in an experiment are simply the result of random differences that arise from drawing two finite samples from same populations
Cellular respiration
Catabolic pathways by which electrons are removed from various molecules and passed through intermediate electron carriers to o2, generating h2o and releasing energy
Adaption
The evolutionary process that leads to the development or persistence of such a trait
Genome
Complete DNA sequence for a particular organism
Computational model
System in which the interactions among components are expressed as mathematical functions
Regulatory system
System that uses feedback information to maintain a physiological function or parameter at optimum level
