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Biology 1023 Final
N/A
198
Biology
Undergraduate 1
04/15/2013

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Term
Molecular Clocks
Definition
- Most mutations are neutral, if mutations occur at a constant rate they can be used to measure evolutionary change time
- Longer periods of time; divergence allows for greater accumulation of mutations
- Not perfectly linear bc not all organisms evolve over the same rate
Term
Horizontal Gene Transfer
Definition
- Any process in which an organism incorporates genetic material from another organism without being the offpring of that organism
Term
Vertical Evolution
Definition
- Changes in groups due to descent from a common ancestor
Term
Fossils
Definition
- Preserved remains of past life on earth
- Palaeontologists study them
- Most rocks are sedimentary; sediment piled up and became rock
- First known: 3.5 BYA
Term
Dating Fossils: Relative Dating
Definition
- Place fossils in relative sequences based on the layer in which they appear
- Older rocks are deeper
Term
Dating Fossils: Absolute Dating
Definition
- Use elemental isotypes in accompanying rock
- Use half-life and amount of remaining isotope to determine it's age
Term
History of Life on Earth
- Geological Time Scale
Definition
4.55 BYA- present
Term
History of Life on Earth
- 4 Eons
Definition
1. Hadean: Molten rocks (H2Ovap, no liquid)
2. Archean: Ancient rocks
3. Proterozoic: Early life
4. Phanerozoic: Visible life
Term
Mass Extinctions
Definition
5 Mass extinctions; 6th is human activity affect on earth in present
- boundaries between geological time periods are often based on these events
Term
Life in Archean Eon
Definition
Microbrial life 1st evolved in primordial oceans
All life forms were prokaryotic and anaerobic
Term
Stromatolites
Definition
Layered structure of calcium carbonate (CaCO)2
Formed by cyanobacteria growing in mats on the shoreline
Term
Key points in History of Life: Archean
Definition
Origin of life: ~3.8 BYA
microfossils of prokaryotes; stromatolite mats, heavy meteorite activity
temperature cools, organic molecules appear and persist
Term
Proterozoic Eon
Definition
Eukaryotes evolve in early Proterozoic (2-2.5bya)
- membrane bound organelles, multiple chromosomes, nuclear envelope
Multicellular eukaryotes rise 1.5 bya
- leads to specialized reproductive cells, diploidy and sexual reproduction
Multicellular animals emerge toward the end of the eon
Term
Symbiotic Origin of Eukaryotic Genome
Definition
2 organisms living in direct contact
- Archaeon and bacterium in one eukaryotic cell
Term
Endosymbiotic Origin of the Eukaryotic Genome
Definition
2 organisms, one living inside the other
- smaller bacterium becomes part of the archaeon genome
Term
Phanerzoic Eon
Definition
Proliferation of multicellular eukaryotic life extensive (543 may-today)
Term
Cambrian Explosion
Definition
Abrupt increase in diversity of animal species; cause unknown
Term
Phanerozoic Eon; Ordovician Period
Definition
Primitive land plants and arthropods first invade land
Term
Phanerozoic Eon, Silurian Period
Definition
Large colonization by terrestrial plants and animals
- spiders and centipedes
- earliest vascular plants
Term
Phanerozoic Eon, Devonian Period
Definition
Ferns, horsetails and seed plants emerge
age of fishes and tetrapods (amphibians emerge)
Term
Phanerozoic Eon, Carboniferous Period
Definition
Rich coal deposits formed
First flying insects, amphibians, reptiles
Term
Phanerozoic Eon, Permian period
Definition
Forest shifts to gymnosperms
First mammal-life reptiles appeared
At the end, largest known mass extinction event
Term
Phanerozoic Eon, Mesozoic Era
Definition
Permian extinction: marks boundary between Palaeozoic era and mesozoic eras
Age of dinosaurs
Term
Phanerzoic Era,Mesozoic Era, Triassic Period
Definition
Gymnosperms dominant land plant
First dinosaur; first true mammals
Term
Phanerozoic eon, Mesozoic era, jurrasic period
Definition
birds first evolved
Term
Phanerozoic eon, Mesozoic era, jurrasic period
Definition
birds first evolved
Term
Phanerozoic Eon, Mesozoic Era, Cretaceous Period
Definition
Earliest flowering plants, angiosperms
mass extinction at the end; many dinosaurs and other species died out
Term
Phanerozoic Eon, Cenozoic Era, Tertiary Period
Definition
Angiosperms became dominant land plant
Mammals that survived mass extinction expanded rapidly
A lot of diversification of birds
Hominids appeared about 6MYA in africa
Term
Phanerozoic Eon, Cenozoic Era, Quartenary Period
Definition
Periodic Ice ages in Europe and North America
Term
Phanerozoic Eon, Cenozoic Era, Quartenary Period
Definition
Periodic Ice ages in Europe and North America
Term
Major Transitions
Definition
endosymbiosis and formation of mitochondria, sexual reproduction, multicellularity,complex membranes
Term
Taxonomy of Humans
Definition
Homo= human
sapiens= thinking
Term
Simplified Lineage of Human Taxonomy
Definition
Kingdom Metazoa
Phylum Chordata
Subphylum Vertebrata
Class Mammalia
Order Primates
Family Hominidae
Genus Homo
Species Sapiens
Term
Great Apes
Definition
Their DNA is very similar to humans
>95% similar for gorilla and chimps
all highly intelligent; use tools
Divergence from chimps ~6 MYA
Term
Australopithecus Afarensis
Definition
Early robust bipedal ancestor of human lineage
~3-4 MYA
Term
Homo Habilis
Definition
"Handy man"
Bipedal, 3-4 feet tall, larger brain than most apes
Fashioned tools
Omnivorous but ate more meat than australopithecine's
Mix of ancestral and modern characters- probably had less body hair than chimps
Term
Sudden Brain Increase in Ancestors
Definition
Prior to H. habilis, brain size remained static for millions of years
a period of violent climate swings, vegetation changed from grassland to forest and back again several times over a 200 000 year period
a larger brain may have been rqd to adapt to rapid changes
Term
How early humans hunted animals
Definition
persistence hunting: the hunting method still used by some modern humans
due to lack of body hair and presence of sweat glands for thermoregulation
Term
Homo Erectus
Definition
Fossils discovered as far away as indonesia from africa
hunter-gatherers with larger brains
coordinated hunters
body hair reduced and sweat glands increased
fire/ cooking
smaller skull, teeth, surface area for jaw attachment than hibilus
Term
Benefits of Cooked food ( erectus cooked their food)
Definition
- safer food/ reduces spoilage
significant increase in energy extracted from food
facilitates further increase in brain size
Term
Homo floresiensis
Definition
"Hobbit people of flores
1 m tall
used stone tools, fire, complex hunting skills
Term
Homo neanderthalensis
Definition
European hunter- gatherers
DNA sequences suggests no or limited interbreeding with modern humans
more elaborate tools and weapons than erectus, may have had a form of religion
lived 300000-30000 years ago
Term
Homo sapiens
Definition
Originated in rift valley ~200 000 yrs ago
culturally advanced; more refined tools, burial more advanced, larger brains
probably drove neanderthals extinct ~30000 yrs ago
Term
Hominid Lineage
Definition
example of Mosaic evolution
grasping hands- apes
bipedalism- australopithecus
reduced hair- erectus
dentition, digestive tracts
advanced speech- sapiens
brain size (facilitated by diest and shift in energy from digestive tract to brain ie. cooking food allowed natural selection to favor smaller digestive tracts and shift energy resources to making larger brains
Term
Human: Intra-specific variation
Definition
adaptation to local environments
Body size and shape: ears and limbs shorter and smaller, bodies leaner and thinner in warmer climates, stockier in colder
skin color: melanin, UV light
Term
Modern definition of evolution
Definition
a change in allele frequencies in a population over time
Term
Population Genetics
Definition
The study of genes and genotypes in a population
- the extent of genetic variation, why it exists and how its maintained- how it changes over time
Term
Mutation
Definition
a heritable change in genetic material
new mutations are more harmful than beneficial
Term
Gene mutation
Definition
Alters the DNA sequence
2 basic alterations:
- base change
- addition or subtraction of nucleotides
Term
Point mutation
Definition
Single base pair is affected in a DNA sequence
Term
Macroevolution
Definition
A large scale evolutionary process that results in a new species
- depends on separation time for 2 populations
short time:small change
long time: large change
Term
Theory of Natural Selection
Definition
Main proces by which species change and evolve.
- IF there us variation in a population and IF some of that variation is heritable, THAN there will be a struggle for existence
- because of the struggle competitors who are better at competing will survive and reproduce- their traits will show more over time
Term
Binomial nomenclature
Definition
Genus: capitalized
Species: non capitalized, italicized
Term
Long Time scale Evolutionary Evidence: Biogeography
Definition
Study of geographical distribution of extinct and modern species
Isolated continents and islands have endemic species
Term
Convergent Evolution
Definition
2 different species from different lineages show similar characteristics because of a common environment
Term
Selective Breeding
Definition
Programs to modify the traits of a domesticated species- made possible by genetic variation
Term
Homologous Genes
Definition
Genes derived from the same ancestral gene
- 2 gene sequences may be similar due to the same ancestral gene but not identical because of the accumulation of different random mutations
Term
Biotechnology
Definition
Include the use of living organisms as products from living organisms as a way to BENEFIT HUMANS
- molecular genetic techniques to benefit humans
- Swanson and Boyer: first human gene into a bacterium
Term
Manual Sequencing
Definition
Add 5 things to test tubes, see which affects gene of interest
1. many copies of target DNA
2. Primers
3. DNA polymerase
4. many copies of radiolabelled 4 ddNTPs'
5. few copies of one of the 4 ddNTPs'
Term
Proteins 4 level of structure
Definition
Primary: sequence within chain
Secondary: Hbonds between side groups
Tertiary
Quarteniary
Term
Western Blotting
Definition
Detects specific proteins
Probes with antibodies
Term
Northern Blotting
Definition
Detects pattern of gene expression
- uses radiolabelled probes
Term
Genes
Definition
Units of heredity (universal)
Term
Gene as a process of functional product
Definition
Organized unit of DNA sequence that enables a segment of DNA to be transcribed in RNA- which results in a formation of a functional product
Term
Functional Products (of genes)
Definition
Non structural genes
enzymes and other proteins, tRNA, mRNA
structural genes (90% of all genes)
Term
Process of Transcription
Definition
Initiation: pi bonds, polymerase unwinds

Elongation: in "transcription bubble" (open complex)

Termination: occurs when RNA reaches terminator sequence
* in eukaryotes, RNA requires post transcriptional processing before leaving nucleus
Term
Codons
Definition
Set of 3 bases in an organized unpunctuated fashion
Term
Introns
Definition
any nucleotide sequence within a gene that is removed by RNA splicing
- much of human genome is made up of these
Term
Exons
Definition
Any nucleotide that remains present while introns are spliced
Term
Splicing
Definition
Process by which introns are removed from pre- mRNA and exons are spliced together to form a mature RNA
-requires spliceosome complex and small RNA proteins (snRP's
- function: migration from nucleus, protection and translation
* critical for creating protein variants
Term
Organization of Bacterial RNA
Definition
5' ribosomal binding site; start codon AUG
1 of 3 stop codons: UUA, UGA, UAG
DNA sequence is transcribed to mRNA
codons in mRNA complement anticodons in tRNA
Term
tRNA
Definition
Common features:
cloverleaf structures
anticodons
acceptor stem for AA binding
- different molecules encoded by different genes
Term
Ribosomes
Definition
Prokaryotes have 1 kind
Eukaryotes have distinct ones in different cellular compartments
p site: peptidyl
a site: aminoacyl
e site: exit site
* all sites for tRNA binding
Term
Stages of Translation: Initiation
Definition
mRNA and tRNA and ribosomal subunits assemble, and require the help of energy and ribosomal initiation
Term
Stages of Translation: Elongation
Definition
1. Aminoacyl tRNA brings next amino acid to A site. Peptidyl brought to P site; anticodon and codon binding

2. a peptide bond forms to extend growing chain
- RNA catalyzes peptide bond formation

3. Translocation of ribosome; moves 1 codon down
- shifts tRNA from P to E and E to P
Term
Stages of Translation: Termination
Definition
Stop codon is placed in Exit site
Term
Recombinant DNA
Definition
a mixture of DNA from 2 different organisms which can be used to make hybrids
Term
Gene cloning
Definition
Process by which many copies of a "gene of interest" are made
- allows researchers to study gene directly
Term
Types of RNA
Definition
mRNA: transcribed from DNA; directs order of AAs during translation
tRNA: transports AA's for polypeptide assembly
rRNA: provides site where polypeptides are assembled
Term
Central Dogma of DNA
Definition
DNA
(transcription)
RNA
(mRNA)
Protein/ Polypeptide
(translation)
Term
DNA replication in the telomere
Definition
Requires enzyme telomerase; composed of protein and RNA
- RNA portion is complementary to repeat sequence in 3' overhang
W/O enzyme, chromosomes of eukaryotes become progressively shorter with each replication
- always found in high levels in germ cells
Term
DNA polymerase
Definition
Always works 5'---> 3'
Cleaves off 2 terminal phosphates from each
deoxynucleoside triphosphate
- energy is released to form phosphodiester bonds
cannot bind with out an RNA primer
solved by telomerase
Term
RNA Primers
Definition
1st nucleotide to match up with exposed bases in daughter strand
Term
Leading strand
Definition
replicates in a continuous 5' --> 3' direction
Term
Lagging strand
Definition
Replicates in 3' --> 5' direction in small fragments
Term
Okazaki fragments
Definition
stretches of 2-3 hundred nucleotides that are synthesized 5' --> 3' away from replication fork
- stitched together with ligase
- discontinuous/ lagging
Term
Origin of Replication
Definition
A section of DNA rich in A and T
Term
Replication Forks
Definition
2 Areas where H-bonds are going to be broken next on the R side of the replication bubble
Term
Replication bubble
Definition
Where 2 DNA strands come apart at origin of replication
Term
Bidirectional replication
Definition
replication goes in both directions from a replication bubble on the forks
- eukaryotes have multiple origins of replication
- prokaryotes have 1
Term
Mechanisms of Reproduction: Semi conservative
Definition
2 Hetero and 2 Homo offspring from parent strand
Term
Mechanisms of Reproduction: Conservative
Definition
4 Homo daughter strands; 3 blue 1 red vice versa
Term
Mechanisms of Reproduction: Dispersive
Definition
4 complete hetero daughter strands
Term
Chargaffs Rules for DNA
Definition
C=G and A=T
C+G= A+T
Term
DNA nucleotides
Definition
*DNA is genetic material*
all strands have -PO4 at 5' end and Hydroxyl group at 3' end
* written 5' --> 3'
Term
Bacterial Transformation
Definition
A genetic change in a bacterial cell brought about by the uptake of genetic material from the environment
- studied by Fredrick Griffith in his studies with a pathogen
Term
4 Criteria for Genetic Material
Definition
- Information
- Transmission
- Replication
- Variation
Term
The Scientific Method
Definition
The procedure researchers use to answer question
** an iterative process that, if successful, leads to a theory**
- we can falsify a hypothesis but cannot prove it
Term
Purines
Definition
Double ring
A and G
Term
Pyrimadines
Definition
Single Ring
T and C
Term
How Nucleus was found to hold instructions for the cell
Definition
Took 2 types of mermaids win glass and splices eachothers middles onto eachother ( nucleus is found in base)
When allowed to regrow, and base and top were same and middle remained different
nucleus contains proteins, DNA, RNA
Term
Restriction Enzymes
Definition
Cut DNA at specific places, target palindromic DNA
Term
Palindromic DNA
Definition
DNA that reads the same forwards and backwards (complementary to parent strand)
eg. G A A T T C = parent
C T T A A C = complementary
Term
Restriction Sites
Definition
Location where a specific DNA molecule is recognized by a restriction enzyme
Term
Genetically Modified Organisms (GMO's)
Definition
Organism that carries genes introduced by genetic molecular techniques
- transgenic organisms eg. Rats
- gene replacement vs addition
- can be used to create "knock out mice" (engineer a similar sequence but mess it up slightly in order to test a hypothesis)
Term
Gene Therapy
Definition
DNA as a pharmaceutical agent to treat disease
- most common: replace mutated gene with a functional gene
*Desired DNA is packaged within a vector, which is used to get inside DNA cells, once inside it becomes expressed by the cell machinery, treating the disease*
Term
Molecular Pharming
Definition
Farm animals to make pharmaceuticals
- can be used to make human hormones or other desired gene product
- a transgenic animal can be designed to produce the desired gene in their milk for easy harvest
Term
Animal Cloning
Definition
Whole genome of animal is cloned
- somatic cells as a source for DNA , but insert germ cells which give rise to embryos genetically identical to donor of somatic cells
- egg from sheep + donor sheeps' mammary cell= put into donor sheep= baby of exact same genes
Term
Colony Hybridization
Definition
Can be used to select a gene of interest
* uses gene probes (single stranded nucleic acids that are complementary to gene of interest and are usually labelled radioactively)
Term
PCR
Definition
Method of making copies of DNA strands
- Taq polymerase
- nucleoside triphosphate
- buffers and chemicals
1. Denaturation: heated to 90 deg
2. Annealing: lowered to 50 or 65 deg
3. Extension: increased to 70 deg and then to 80 deg
Term
RT- PCR
Definition
uses reverse transcriptase
Has an extra prep step PCR doesn't
- reverses normal transcription process and takes RNA and synthesizes a DNA from its template (cDNA)
- mRNA> DNA> mRNA> cDNA
Term
Southern Blotting
Definition
Detects specific genes within a sequence
- uses gel electrophoresis and DNA probes
- can be used to detect gene families
Term
Blue/ White Screening
Definition
Mix DNA's from B galactosidase gene and B globin gene
- let sticky ends base pair
- add DNA ligase to covalently link a piece of chromosomal DNA to the plasmid
- mix e.coli plate cells over night and see which ones are white or blue
white: hybrid
blue: no insert

technique that researchers use in the cloning process to determine whether or not a vector contains recombinant DNA
Term
DNA Helicase
Definition
An enzyme (protein) that separates the complementary DNA strands in the process of DNA replication exposing the bases of the two strands.

one at each replication fork in DNA strand
Term
Topoisomerase
Definition
Flattens out before DNA helix comes to prevent it from knotting and interfering with separation of 2 parental strands
Term
DNA primase
Definition
Adds RNA Primers to DNA
Term
DNA Ligase
Definition
Responsible for joining okazaki fragments in lagging strand
Term
Promoter
Definition
sequence of bases at the start of a gene
Term
Terminator
Definition
Sequence of bases at the end of a gene
Term
Vectors
Definition
Deliver DNA to carrier (plasmids)
Term
Plasmids
Definition
Extra chromosomal bits of DNA that can be transferred in transformation
Term
Morphological Species Concept
Definition
A group of organisms that maintains a distinctive set of attributes in nature
Species categorized by physical characteristics
- anatomy and external morphology
- cellular traits
- molecular traits
Term
Cladistics
Definition
Study and classification of species based on evolutionary relationships
- discriminates among possible phylogenic trees and chooses least complex tree
- compares homologous traits that exist in 2 or more character states
Term
Homology
Definition
Similarities in various species that occur because they are derived from the same ancestor
- human aren, cat front leg, bat wing
Term
Growth Rate influential Genes
Definition
Genetic variation can influence morphology by controlling relative growth rates of different parts of the body during development
Term
Heterochrony
Definition
evolutionary changes in the rate and timing of developmental events
eg. human skull vs. chimpanzee growth
Term
Heterochrony
Definition
evolutionary changes in the rate and timing of developmental events
eg. human skull vs. chimpanzee growth
Term
Allopatric Speciation
Definition
When members of a species become geographically separated
Term
Sympatric Speciation
Definition
Members of a species are within the same range diverge into 2 or more different species even though there are no physical barriers (common in plants)
Term
Taxonomy
Definition
Science of describing, naming and classifying living and extinct organisms and virus'
3 domains: Bacteria, Archea, Eukarya
Term
Systematics
Definition
Study of biological diversity and evolutionary relationships among organisms, extinct and modern
Term
Migration
Definition
Gene flow occurs when individuals migrate between populations having different allele frequencies
- reduces differences in allele freq's and enhances genetic diversity
Term
Non random mating
Definition
Individuals choose mate regardless of pheno or geno type
- Assortative: similar phenotypes most likely to mate
- Disassortative: dissimilar phenotypes more likely to mate
Term
HOX genes
Definition
master developmental genes that produce HOX proteins- transcription factors that turn on/off other genes
-found in all animals
- the more genes, the more complex the body structure
Term
Sypleisomorphy
Definition
Shared ancestral character by 2 or more taxa from ancestors OLDER than last common ancestor
Term
Synapomorphy
Definition
Shared derived character by 2 or more taxa from its last common ancestor
Term
Anagenesis
Definition
Single species evolves into a different species
Term
Cladogenesis
Definition
A species diverges into 2 or more species
Term
Directional Natural Selection
Definition
Extreme phenotypic ranges have more reproductive success in a particular environment
Term
Stabilizing Selection
Definition
Survival of individuals with intermediate phenotypes
Term
Disruptive Selection
Definition
Survival of 2 or more genotypes that produce different phenotypes
Term
Balancing Selection
Definition
Maintains genetic diversity by balanced polymorphism: 2 or more alleles kept in balance and maintained in a population for many generations
- heterozygote advantage
- negative frequency dependent selection (rare species have higher fitness)
Term
EVO-DEVO
Definition
compares developmental cycles of different organisms to understand ancestral relationships and the developmental mechanisms that bring about evolutionary change
- involves discovery of genes that control development
Term
Ecological Species Concept
Definition
Each species occupies an ecological Niche, as well as its influence on the environment and other species
- can be used to distinguish species
- bacterial species defined by this
Term
Spontaneous Mutations
Definition
Abnormalities in biological processes
- 1 mutation in 1 million genes
Term
Induced Mutation
Definition
Environmental agents (physical and chemical) induce mutations
Term
Post-Zygotic Mechanisms/ Barriers
Definition
Factors that kick in after fertilization
- hybrid doesn't survive
- hybrid survives but is sterile
- hybrid fetus survives briefly
inviability: cannot progress past embryo
sterility: sterile
breakdown: genetic abnormalities in subsequent generations
Term
Biological Evolution
Definition
Heritable change in more than 1 characteristic of a population or species from one generation to the next
Term
Biological Evolution
Definition
Heritable change in more than 1 characteristic of a population or species from one generation to the next
Term
Micro evolution
Definition
Small scale evolution with a change to 1 gene
Term
Allele frequency equation
Definition
= #copies of specific alle/ # total allele for that gene

eg. Rr + 2(rr)/ 2(RR)+(2(Rr)+(2(rr)= 0.3
Term
Reproductive isolation
Definition
Prevents species from interbreeding successfully with any other species
-doesn't pertain to A-sexuals
- spp can breed but don't
- cant apply to extinct organisms
- difficult to determine in nature
Term
Developmental Genes
Definition
Key genes that may influence:
cell differentiation
cell migration
cell death
cell division
- interplay produces an organism with a specific body type
Term
Neutral Theory of Evolution
Definition
Due to genetic drift and has no preferential selection for a particular allele
- most genetic variation is due to genetic drift (neutral mutations that have attained high frequencies)
Term
Ames Test
Definition
Determines if an agent is a mutagen or not.
- uses salmonella typherium that cannot synthesize histodine
-if a large amount of bacteria grows there is a mutagen
Term
Hardy Weinberg Formula
Definition
(p+q)^2=1
Term
Requirements for Hardy Weinberg equilibrium
Definition
- no migration
- no mutation
- random mating
- large population size
- no natural selection
Term
Anatomical Homology
Definition
Same set of bones/ limbs that have gone through evolutionary change
Term
Developmental homology
Definition
species that differ as adults but have similar embryonic stages
Term
Molecular homology
Definition
gene evolution that involves changes in DNA sequences
Term
Polyploidy
Definition
organism that has 2 or more sets of chromosomes
- can occur through non-disjunction (one gamete gets both sets of chromosomes in meiosis)
Term
Autopolyploidy
Definition
Contains chromosomes from 1 species
Term
Allopolyploidy
Definition
Chromosomes from 2 or more species
Term
Silent gene mutation
Definition
A base change that doesn't affect the AA sequence
- genetic code is degenerate
Term
Missense Mutation
Definition
a base change which changes in 1 amino acid in a polypeptide
Term
Nonsense mutation
Definition
a base change to a stop codon from a normal codon
Term
Frameshift mutation
Definition
an addition or removal of a nucleotide resulting in codons which are not mulitples of 3
Term
Morphological analysis
Definition
first systematic studies focused on morphological features of extinct and modern species
- must use homologous traits
Term
Convergent Evolution
Definition
Traits arise independently due to similar environments
- can cause problems in morphological analysis
Term
Molecular Systematics
Definition
analysis of genetic data such as DNA and AAs to identify and study genetic homologies and propose phylogenic trees
Term
Prezygotic mechanisms
Definition
mechanisms that occur prior to formation of fertilized egg/sperm
geographic: spacial differences/ environmental problems
ecological
temporal: reproduce at diff times of year
behavioral: changes in song/ dance
mechanical: incompatible genitalia
Term
Steps in Speciation
Definition
1: Reduce gene flow between 2 populations
2. Divergence of populations (genetic drift/ random selection)
3. reinforcement of reproductive isolation (pre/post zygotic mechanisms)
Term
Genetic Drift
Definition
Changes in allele frequencies due to random chance
- random events unrelated to fitness
Term
Bottleneck genetic drift
Definition
Population is reduced then rebuilds
- the new population has less genetic variation
Term
Founders effect: genetic drift
Definition
small group of organisms separates from large populations and establishes a new colony
Term
Sexual Selection
Definition
Traits of sexually reproducing species that make it more likely for them to choose their mate/ engage in successful mating
Term
Intrasexual
Definition
Same sex interaction; males fight for a female
Term
Intersexual selection
Definition
opposite sex; female choice (showy males)
- cryptic choice: pollen incompatibility in plants
Term
Genotype frequency equation
Definition
# individuals w. genotype in population/ total individuals in pop.

eg. 49 RR , 42 Rr 9 rr
9/ 49+42+9 = 0.09
Term
Reproductive Success
Definition
The likelihood of an individual contributing viable and fertile offspring to a new generation
Term
Fitness
Definition
A relative measure of reproductive success
Term
Direct DNA repair
Definition
Enzyme removes a modification to genome
Term
NER DNA repair
Definition
all eukaryotes and prokaryotes have this
- region encompassing damaged strand is removed from DNA, undamaged strand is used as template for new re-synthesis
Uvr A, B, C, D
Term
Methyl Mismatched DNA repair
Definition
Detects and repairs base pairing
- recognized correct sequences and uses it as a template to repair damaged strand
- E. coli, MutS, MutL, MutH
Term
Species
Definition
Group of related organisms that share a distinct form
- members of the same spp are capable of interbreeding
Term
Population
Definition
Members of the same species that are likely to encounter each other and have the opportunity to breed
Term
Ionizing Radiations
Definition
High energy radiations that can penetrate through biological materials deeply
- Xrays and gamma rays cause DNA breaks
Term
Non-ionizing radiation
Definition
Low energy radiation that penetrates through the surface
- UV rays
Term
Thyamine Dimer
Definition
covalent link between 2 thiamine
- prevents base pairing during replication
- incorrect bases happen and or gaps in bases
Term
Germ line cells
Definition
cells that give rise to gametes
- a full body mutation happens if germ line cells are affected
Term
Somatic Cells
Definition
All other cells in your body other than germ line
- patch mutations happen if somatic cells are affected
Term
Biological Species Concept
Definition
A species is a group of individuals whose members have the potential to interbreed and to produce viable offspring but cannot mate with other species
Term
Gradualism
Definition
Each new species evolves continuously over a long time span
- large phenotypic differences that produce new species are due to the accumulation of genetic changes
Term
Punctuated Equilibrium
Definition
species that are in equilibrium for long periods and then short rapid bursts of changes
- more sporadic
Term
Clades: monophyletic
Definition
A group of species of the most recent common ancestor and all of its descendants
Term
Clades: Paraphyletic
Definition
Group contains a common ancestor but not all of its descendants
Term
Clades: Polyphyletic
Definition
Contains species that do not share their most recent common ancestor
Term
Sigma Factor
Definition
A protein that binds to both RNA polymerase and the promoter for a gene. It allows RNA polymerase to recognize where a gene starts and so is involved in the initiation phase of transcription
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