Exploring Life Flashcards
(Manifestations of life, Theories on the Origin of Life, Alife, Scientific Method)
What is the science of life?
Biology
Manifestations of life
- Built of cells
- Reproduce by themselves
- Living things develop
- Interact with other organisms and their physical environment
- Capture and process energy
- Characterized by hierarchical levels of organization
- Evolve and adapt
What are the building blocks of life?
cells
Two types of cells and their difference
- Eukaryotic cell, 1-10 microns (membrane-bound organelles, DNA in nucleus)
- Prokaryotic cell, 10-100 microns (nonmembrane-bound organelles, no nucleus)
What contains the cell’s genetic material?
DNA
These are the units of inheritance that transmits information from parents to offspring
Genes
It is a process in which characteristic of a species change over a period of time
Evolution
What accounts for the unity and diversity of life?
Evolution
Are viruses alive?
No, because,
* theyre not made out of cells
* They don’t grow
* They can’t make their own energy (no host, no virus)
Theories on the origins of life
- Spontaneous generation
- Interplanetary/Cosmozoic theory
- Abiogenesis/Biogeochemical theory
- Special creation
Describe spontaneous generation
Higher organisms just appear and don’t evolve from other life forms
Experiments used to disprove: * Flesh of dead animals were placed in sealed and open containers (1668 - Francisco Redi)
* Pasteur’s test of spontaneour generation (broth sterilized and open vs sterile broth in swan-neck flask)
Describe Interplanetary/Cosmozoic theory
Life originated from a distant planet (panspermia)
What’s abiogenesis/biogeochemical theory?
Life evolved from inorganic matter because of the chemical and physical processes in Earth’s primordial environment
Four hypothetical stages of Abiogenesis
- Biotic synthesis of small organic molecues
- Joining of small molecules into polymers
- Origin of self-replicating molecues
- Packagin of molecules into “protobionts”
What are protobionts
- Self-assembling biomolecules
- Where living cells may have arisen from
Theoretical basis of Abiogenesis
- Oparin and Haldane
- Early Earth was conducive for creation of organic molecules (w/ Carbon)
- There exists a “primeval soup” of organic molecules that can be created in an oxygen-less atmosphere
Earth’s primeval atmospheres
- Hot hydrogen gas
- Water, CO, CO2, N2, NH3, CH4 (intense lightning, UV rad, volcanic activity)
- 1st seas - from torrential rains when earth cooled down
Experimental basis for abiogenesis
Miller-Urey Experiment
1. Water vapor interacts with an electrode that produces simple organic compounds
2. Water with compounds fall into the water and form amino acids
Problems with the theory:
* No detailed theoretical path from complex orgmol to life form
* No mechanism for RNA building blocks
ALife (Artificial Life)
Synthesizing life-like behavior in software, hardware, and biochemicals
John von Neuman - self-reproducing computation-universal cellular automata
Types of ALife
- Soft (software)
- Hard (hardware) - robots
- Wet (wetware) - synthetic biology
How scientists created the first alife
Recombinant DNA tech
* decode dna
* synthetically create dna
* transplant adna to a living bacterium
* allow bacterium to divide and create daughter bacteria
* add antibiotic that kills the bacteria with authentic dna but not the one with adna
Applications of ALife
- better theoretical understanding of phenomena
- allows to extend studies to a larger domain of biologically possible life
- genetic algorithms
2 Reasonings
- Inductive (specific to general)
- Deductive (general to specific)
Scientific method (process)
- Observation
- Hypothesis (explanation of observation)
- Prediction (expected consequences of a correct hypothesis)
- Experiment (test of a hypothesis)
- Conclusion
