Bio 2 test 1 Flashcards
Characteristics of Living Organisms
Unity
- Cells and Organization
2.Energy Use and Metabolism - Response to Environmental Change
- Regulation and Homeostasis
- Growth, Development and Reproduction
- Biological Evolution
Descent with Modification
Heritable traits that promote survival and reproductive success
Adaptation
Any modification that makes an organism better suited to its way of life
Structure determines function
Structure: opposable thumb
Function: strong grasp
Information flow, exchange and storage
The growth and behavior of organisms are activated through the expression of genetic information.
Pathways and transformation of energy and matter
biological systems grow and change by processes based upon chemical transformation pathways and are governed by the laws of thermodynamics
Systems
living systems are interconnected and interacting
4 Overlapping Stages
- Nucleotides and amino acids produced prior to existence of cells
- Nucleotides and amino acids became polymerized to form DNA, RNA and proteins
- Polymers became enclosed in membranes
- Polymers enclosed in membranes evolved cellular properties
Reducing Atmosphere Hypothesis
Little free oxygen. High water vapor, nitrogen and CO2. Too hot for liquid water
Spontaneous Formation of organic molecules
monomers evolved and joined to form polymers. Abiotic Synthesis: which means that organic molecules would be synthesized to organic complex molecules through UV radiation, lighting etc.
Miller and Urey’s Apparatus Experiment
Showed that biochemicals could be produced from simple nonbiological sources. Yielded HCN, CH20, sugars, amino acids and nucleotide bases
Extraterrestrial Hypothesis
organic carbon from asteroids and comets stocked prebiotic soup.
Deep Sea Vent Hypothesis
superheated water rich in H2S and metal ions mixes with cold water. Organics formed in temperature gradient around vents
Origin of first cell
Clay hypothesis: simple organisms polymerize on solid surfaces (clay and mud) into more complex organisms
Cell-like structures: Protobiont
- Boundary (membrane), Polymers inside contain info, Polymers inside with enzymatic functions and self replicating
Chemical Selection- RNA world
- Rna in Protobionts can store info, capacity for replication and enzymatic functions on ribozymes
Advantages of DNA/RNA/ Protein World
Information Storage
- DNA takes over information storage and allows for RNA to do other things
-DNA suffers less from mutation
Metabolism
- proteins have greater catalytic efficiency
- proteins can do many other task such as the cytoskeleton and transport
Fossils
Remains and traces of past life
Paleontology
The study of the fossil record
Relative Dates Vs Absolute
Relative dating (don’t know the date but you can compare it to other such as saying it’s older than another) vs absolute (direct time)
Assemblage
collection of fossils in the same strata
Strata + Fossils
Older fossils are found at the deepest layers
Factors that affect the fossil record
Anatomy, Size, number, environment, time, geological processes and paleontology
Fossil Dating- Absolute
Radiometric Dating: the length required for half the atoms to change into something else
-unaffected by temp, light, pressure etc.
Dating of fossils: relative (using index species) vs. absolute (using radioisotopes, half-life,
calculation)
Geologic Time Scale
Changes in organisms result of 1). Genetic Changes 2. Environmental Changes
Patterns of mass extinction correlated with:
1. Climate/Temperature
2. Atmosphere
3. Land Masses
4. Floods/ Glaciation
5. Volcanic Eruptions
6. Meteorite Impacts
Paleozoic era
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian
Mesozoic era
Triassic, Jurassic, Cretaceous
Cenozoic era
Tertiary, Quaternary
Primate Evolution
- rotating shoulder joint
- big toe and thumb widely separated from others
- Stereoscopic vision: the brain’s ability to interpret visual information from both eyes to create a clear three-dimensional (3D) image
Extinctions
Ordovician: Glacial caused sea levels to rise and fall dramatically, moving shorelines repeatedly. Continental erosion changed atmosphere and ocean chemistry.
Devonian: Land plants consumed atmospheric carbon dioxide (CO2), which caused global cooling. Weathering plant roots released nutrients into the sea, causing algal blooms and oxygen depletion.
Permian: lava covered mass areas. Acid rain and global warming
Triassic: atmospheric CO2 levels rose causing global warming and ocean acidification.
Cretaceous: Volcanos acidified oceans and increased global temperatures. Tectonic plates depleted oceans of oxygen. Asteroid impact caused rapid cooling.
6th Mass extinction: burning of fossil fuels, farming and deforestation elevate CO2 levels that cause ocean acidification. Pollution, habitat loss, overfishing and introduction of invasive species.
Species
group of related organisms that share a distinctive form. Capable of interbreeding
Population
members of the same species that are likely to encounter each other and thus have the opportunity to interbreed
History of Evolutionary Thought
Pre-Darwinian: Influenced by theology, myth and superstition
Anaximander: organisms evolve over time
Plato: objects are temporary reflection of ideal forms
Aristotle: all living things can be arranged in a linear hierarchy (scala naturae)
Creationism: a God is absolute creator of heaven and earth, out of nothing, by an act of free will includes Christians, jews and Muslims.
Spontaneous Generation: Sweaty rags in open jar gain after 21 days produced mice
Scala Naturae
Aristotle: father of classic taxonomy
Puts man as the dominate and perfect life form
-sets man above and apart from nature
-incorporated into religious belief that earth and creatures do not evolve
John Ray, Carolus Linnaeus and Eramus Darwin
John Ray: 1st thorough study of the natural world
Carolus Linnaeus: each species has an ideal structure and function and a place in scala naturae. Binomial system of nomenclature
Erasmus Darwin: suggest common descent; evidence in developmental patterns
Lamarck
first biologist to propose evolution and link diversity with environmental adaptation
- concluded more complex organisms are descended from less complex organisms
- Proposed inheritance of Acquired characteristics- Lamarckianism
Charles Lyell
earth is subject to slow but continuous cycles of erosion and uplift.
Uniformitarianism: rates and processes of change are constant
Darwin’s Theory of Evolution
Tortoises: proposed that speciation on islands correlated with a difference in vegetation- adaptation
Finches: speculated they could have descended from a single pair of mainland finch- Speciation
Natural Selection is
Nonrandom
Survival of the Fit
Fitness is the relative reproductive success of an individual. Most fit individual in a population
adaptation
changes that help a species become more suited to its environment. product of natural selection
Comparative Anatomy
Homologous Structures: Anatomically similar because they are inherited from a common ancestor. Ex. limbs have the same bones
Analogous: Serve the same function. Do not share a common ancestor. Convergent Evolution: when organisms that aren’t closely related evolve similar features or behaviors to adapt to similar environments or ecological niches
convergent evolution
analogy- similarity due to convergence
ex. jumping: bullfrog and kangaroo
Comparative Anatomy
Vestigial Structures: fully-developed anatomical structures. Reduced functions. Ex. male breast tissue, wisdom teeth, human tail bone, wings on flightless birds
comparative development
all vertebrate embryos have: a postanal tail, paired pharyngeal pouches, hollow dorsal nerve cord (spinal cord), notochord
The development of an organism (ontogeny) expresses all the intermediate forms of its ancestors throughout evolution (phylogeny)
Biogeography
Alfred Russell Wallace- Father of biogeography
Study of geographical distributions of plants and animals across earth. different mixes of plants and animals in areas separated by water and islands
Molecular Homologies
Almost all living organisms:
use the same basic biochemical molecules. utilize the same DNA triplet codes, same 20 amino acids, ATP as energy.
Genetic Homologies: when very similar, suggest recent common descent
when more different suggest more ancient common descent
PROCESS OF EVOLUTION
- variations are produced by chance mutations and sexual reproduction
- Natural selection selects the fittest organisms
- Natural Selection leads to Adaptation to a particular environment
- process occurs constantly in all species of life on earth
Natural Selection vs Evolution
Natural Selection acts on individuals in a species
Evolution is a property of populations
Population Genetic
study of genes and genotypes in a population
allele frequency vs genotype frequency
Allele: # of copies of a specific allele in a population/ total # of alleles for that gene in pop
Genotype: # of individuals with a particular genotype/ total # of individuals in a population
Natural Selection
Adaptation of a population to the biotic and abiotic environment
Biotic: predation, competition, sexual selection
Abiotic: Climate, water availability, minerals
requires:
1. Variation
2. Inheritance
3. Differential Adaptiveness
4. Differential Reproduction
Major cause of microevolution
Directional Selection
One extreme phenotype is favored over the rest. The curve shifts in that direction
Stabilizing Selection
Intermediate phenotype is favored. Perfect size not fat or skinny
Disruptive Selection
Two or more extreme phenotypes are favored
