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BIO 226 > Final Review (after midterm) > Flashcards

Final Review (after midterm) Flashcards

1
Q

Central dogma

A

DNA (transcription)- RNA (translation)- amino acid chain (folding)- protein
Explains the flow of genetic information from DNA to phenotype

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2
Q

RNA

A

RNA is typically single stranded
Ribonucleic acid
RNA’s shape can be as important as its sequence
Has OH group in position 2 of the ribose

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3
Q

DNA

A

Is double stranded.
Has H group in position 2 of the ribose

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4
Q

RNA Nucleosides

A

Pyrimidines
Purines

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5
Q

Messenger RNAs

A

mRNAS
coding
Carries gentic information from DNA to the ribosomes
Short lived mobile blueprint molecules for protein synthesis

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6
Q

Small nuclear RNAs

A

(snRNAs)
Non-coding
Structural componenets of spliceosomes

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7
Q

Transfer RNAs

A

(tRNAs)
Non-coding
Adaptors between amino acids and mRNA codons

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8
Q

Ribosomal RNAs

A

(rRNAs)
Non-coding
Structural and catalytic components of ribosomes

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9
Q

Micro RNAs

A

(miRNAs)
Non-coding
Short single-stranded RNAs that block expression of complementary mRNAs

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10
Q

Overview of Transcription

A
  1. DNA is unwound
  2. RNA is synthesized following DNA sequence by RNA polymerase (5’-3’)
  3. DNA rewinds
  4. mRNA is released
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11
Q

RNA synthesis

A

The precursors are ribonucleotide triphosphates.
Only one strand of DNA is used as a template
RNA chains can be initiated de novo (no primer required)
Uracyl instead of thymine
Catalyzed by RNA polymerases

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12
Q

How fast is RNA synthesized?

A

50+nt/s Prokaryotes
20nt/s Eukaryotes

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13
Q

How long does mRNA last?

A

Seconds to minutes: prokaryotes
Minutes to days: eukaryotes

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14
Q

Cis elements

A

same side->DNA

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15
Q

Trans elements

A

Across->proteins

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16
Q

Initiation of Transcription (1):

A

RNA polymerase binds to promoter.
Promoter recognized by the RNA polymerase sigma subunit.
ONLY present on the template strand, ensures only sense mRNA is made.

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17
Q

Promoters

A

Short specific DNA sequence (cis element)

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18
Q

Initiation of Transcription (2)

A

RNA polymerase unwinds the two DNA strands to expose a single stranded template.
Formation of phosphodiester bonds between the first few ribonucleotides in the nascent RNA chain
Sigma is released

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19
Q

Elongation

A

RNA chain grows from 5’ to 3’
RNA polymerase continues to unwind DNA: includes helicase activity
DNA re-winding: reforming hydrogen bonds between the two DNA strands: no energy cost

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20
Q

Termination

A

RNA polymerase decouples from DNA template, RNA strand is released.

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21
Q

Intrinsic termination

A

Required cis elements at the end of transcript (p-independent)
GC rich region creates hairpin
Pulls mRNA off

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22
Q

Factor-dependent termination

A

Requires a trans-element rho (p-dependent)
Binds to Rho-utilization site
Disassembles RNA polymerase

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23
Q

RNA polymerase II

A

Transcribes mRNA and some functional (non-coding) RNAs
Assisted by transcription factors-protein complexes that help it recognize and initiate transcription at the promoter
Most promoters contain a TATA box

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24
Q

“TATA”

A

less promoters use other elements to direct RNA polymerase II

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25
Q

Special challenges in eukaryotic transcription

A

Harder to locate promoter
Transcription and translation are decoupled
Eukaryotic DNA is wrapped up around proteins
Eukaryotic transcription is more complex

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26
Q

Transcription initiation in eukaryotes

A

Ordered addition of transcription factors pre-initiation complex.
Recruits RNA polymerase II
RNA polymerase starts synthesis
Phosphorylation of RNA polymerase C-terminal domain recruits mRNA processing proteins in order: CTD- domain at -C end of a protein, capping splicing and poly-adenylation

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27
Q

Capping

A

Co-transcriptional processing of RNA during elongation:
unusual 5’-5’ phosphodiester bond, methylated guanine
protects mRNA from nucleases. recognition signal for translation

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28
Q

SPLICING

A

Co-transcriptional processing of RNA during elongation:
Most eukaryotic genes contain noncoding sequences called introns that interrupt the coding sequences, or exons.
Introns are excised from the RNA transcripts prior to their transport to the cytoplasm

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29
Q

Introns

A

Intragenic regions
Only eukaryotes have them: certain viruses carry sequences from host eukaryotic genomes with introns.
Noncoding sequences located between coding sequences.
Removed from the pre-mRNA and are not present in the processed/mature mRNA.
Are variable in size and may be very large

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30
Q

EXOns

A

Expressed regions
Are composed of the sequences that remain in the mature mRNA after splicing.
Comprise the coding region.

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31
Q

two main mechanisms of spicing evolved in eukaryotes

A

self splicing
RNA/protein complex mediated splicing

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32
Q

Self splicing

A

Primary transcript with enzymatic activity (ribozyme). No protein involvement.
No energy required

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33
Q

RNA/protein complex mediated splicing

A

Enzymes/snRNAs needed to recognize and mediate intron excision (spliceosome).
Reconfiguration of the splicing machinery requires ATP.

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34
Q

In some protozoa

A

Introns splice themselves
A guanosine is used as a co-factor

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35
Q

Co-factor

A

A compound/chemical used to catalyze a reaction
Not a protein

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36
Q

Example of self splicing:

A

Autocatalytic Splicing of rRNA in tetrahymena

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37
Q

Spliceosome-dependent splicing

A

RNA/protein structure
Excises introns from nuclear pre-mRNA
five snRNAs: U1, U2, U4, U5 and U6 (small nuclear RNAs)
Some snRNAs associate with proteins to form SNRP

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38
Q

Splicing and disease

A

60% disease-causing mutations in humans affect splicing (not coding sequences)
Abnormal splicing common in cancer cells

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39
Q

Alternative splicing produces related but distininct proteins

A

isoforms

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40
Q

POLY ADENYLATION

A

Co-transcriptional processing of ENA during elongation

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41
Q

The 3’ poly (A) tail-poly adenylation

A

Polymerase stalls-end of transcription signal at the 3’ end (GT rich)-DSE
Endonuclease activity cleaves transcript downstream of an AU rich region- AAUAAA
Poly A polymerase recognizes processed transcripts as templates to add poly A tail

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42
Q

Purpose of the 3’ poly (A) tail

A

Enhances mRNA stability in the cytoplasm
Mediates mRNA transport across the nuclear envelope

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43
Q

RNA editing and modification

A

RNA can be changed after transcription the functions are not all clear affects RNA structure, function and stability.

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44
Q

Transfer RNAs (tRNAs)

A

Small (90bp)
Adaptors between mRNA and amino acids.
Two ends: anticodone (pairs with the mRNA), amino acid (covalently attached to the 3’ end)
Each anticodon has its own tRNA with a specific amino acid.
Contains chemically modified nucleosides to avoid mispairing with the codon

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45
Q

The structure of transfer RNA

A

tRNA folds to formspecific 3D structures, common among tRNAs.
The 3D structure of the tRNA is important for its function: serves as substrate for amino acid linkage, enters and moves across ribosomal compartments.

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46
Q

Aminoacyl-tRNA synthetase (ATS)

A

Attaches an amino acid to its specific tRNA
21 different ATS exist, one for each amino acid that specifically interacts its corresponding tRNAs

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47
Q

The specificity of a tRNA depends on

A

matching the correct residue (aa) to the corresponding anticodon.

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48
Q

The aa specificity depends

A

primarily on the activity of aminoacyl tRNA synthases.
Connects the right amino acid to the right tRNA

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49
Q

Ribosomes

A

decoding hubs

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50
Q

E.coli

A

Seven rRNA genes distributed among three sites on the chromosome.

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51
Q

rRNA folds up by

A

intramolecular base pairing

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52
Q

Initiation in prokaryotes

A

The Shine-Dalgarno sequence.
1. Small subunit (30S) binds Shine-Dalgarno sequence: with the help of initiation factors.
2. tRNA binds to P site: special formyl-Methionine (fMet) only used for initiation, with the help of initiation factors.
3. Large subunit (50S) binds to 305: with the help of initiation factors.

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52
Q

Mechanism of translation

A

Stages: polypeptide chain initiation, chain elongation (peptide bonds), chain termination

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53
Q

Initiation in eukaryotes

A
  1. Small subunit (40S) binds to Met-tRNA in P-site: with the help of initiation factors.
  2. Small subunit (40S) binds to mRNA 5’-cap: with the help of initiation factors.
  3. Small subunit ‘walks’ along mRNA to start codon (AUG): lands at P site, with the help of initiation factors
  4. Large subunit (60S) binds to 40S: with the help of initiation factors.
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54
Q

Termination of translation

A
  1. Stop codons bind release factors, not tRNAs: stop codons are the only codons in the genetic code without a corresponding tRNA in nature.
  2. Release factor binds A site with stop codon.
    3.Translation machinery disassembles: the absence of tRNA terminates translation.
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55
Q

Stop codons

A

UAG
UAA
UGA

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56
Q

Properties of the genetic code

A

Composed of nucleotide triplets.
Is non-overlapping: coding sequences are never shared between genes.
Is comma free: a mature transcript carries the whole, no stop, coding sequence of a gene.
Is degenerate: there are more than one codon for a given amino acid.
Contains start and stop codons.
Nearly universl

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57
Q

The genetic code in non-overlapping

A

Genes have one single coding frame, such that every nucleotide only participates of a single codon, never two or three.

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58
Q

The genetic code is comma-free

A

There are no pauses in the coding transcript
Once the mRNA is processed, the entire information from a gene must flow from the first ATG to the first STOP codon without interruptions.

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59
Q

Purines

A

Adenosine and Guanosine

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60
Q

Pyrimidines

A

Cytosine
Uridine and thymine

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61
Q

Inosine (I)

A

is a purine RNA dericative formed by deamination of adenine-> RNA modification

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62
Q

Wobble rules

A

identifies base pair interactions between mRNA (3’ end of codon) and tRNA (5’ end of anticodon) that do not follow normal pairing rules (A-T and C-G)

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63
Q

PRION

A

Protein and infection
‘Self replicable’ proteins in the analogous sense that DNA or RNA are self replicable nucleic acids

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64
Q

Prion diseases

A

Ex: Creutzfeld-Jacob (transmissible spongiform encephalopathy)
Rare, degenrative fatal brain disease, Chracterized by protein aggregates in the brain, triggered by presence of a misfolded prion protein

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65
Q

Germinal mutations

A

Only mutations in the germ cells will be transmitted to the progeny.

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66
Q

Somatic mutations

A

Will impact the individual where the mutation occurs but are evolutionary irrelevant.

67
Q

Mutations

A

Create phenotypic variability but also threatens the cell.
Are random and hertiable changes in the sequence of DNA that can no longer be repaired.
Often have deleterious consewuences, but they can also be innocuous or beneficial to the cell/organism
Key for the process of evolution

68
Q

The reigning “paradigm” of mutations

A

Mutations can occur in any cell at any time, and their occurence is ‘random’

69
Q

DNA types of damage

A

Abasic sites (loss of nucleotide, not backbone)
Base mismatches
Modified bases
Inter and intra strand crosslinks
Double stranded breaks (DSBs)

70
Q

DNA damage

A

occurs due to chemical or physical stress on the double helix

71
Q

Spontaneous mutations

A

Mostly from replication errors.
Polymerase-induced mistakes cuasing mutations (slippage)
Followed by defects in the DNA repair mechanism

72
Q

Spontaneous mutation rate

A

m is very low and varies according to: gene size, domains on the chromosome, genome chracteristics (species-specific), cell age
Low frequency
Eukaryotes: once every 100,000,000 replications

73
Q

Induced mutations

A

via known chemical or physical agents (mutagens)
Base analogs, hydroxylating agents, alkylating agents, deaminating agents, intercalating agaents, UV radiation, ionizing radiation.
Higher frequency
Ethylmethanesulfonate (once every 100 replications)
Commonly used to induce mutations and study gene function

74
Q

Point Mutations

A

Single base pair change=single nucleotide polymorphism (SNP)
Can occur anywhere in the genome: coding regions, intergenic regions, non-coding regions of genes (promoters, UTRs, Introns)

75
Q

Types of point mutations

A

Base substitutions
Base deletion
Base insertion

76
Q

Base substitutions

A

(4) Transition (purine replaced by a purine)[A=G];[G=A] or (pyrimidine replaced by a pyrimidine) [C=T]:[T=C]
(8) transversion: (purine replaced by a pyrimidine)[A=C];[A=T]:[G=C]:[G=T]
(pyrimidine replaced by a purine) {C=A]:[C=G]:[T=A]:[T=G]

77
Q

Base deletion

A

the removal of one base pair

78
Q

Base insertion

A

the addition of one base pair-> indels (insertions and deletions)

79
Q

Silent mutations

A

encodes the same amino acid.
Usually the third position of a codon: degenerate nucleotide
No effect on the phenotype
Synonymous

80
Q

Missense Mutations

A

Non-synonymous
Codes for a different amino acid:
chemically similar- conservative: may retain protein function
Chemically different- Non-conservative: more likely to affect protein function

81
Q

Nonsense Mutations

A

Non-synonymous
Changes to a STOP codon (UAA, UAG, UGA)
Generates truncated protein
Likely severe

82
Q

Frameshift mutation

A

Removal or addition of base pairs disrupts the triplet reading frame.
The result is the translation of an abnormal series of aa downstream from the indel and the increased chances of a premature STOP codon producing a truncated protein.
Indels (insetions/deletions) that are multiple of three reconstitute the frame downstream of the last mutation site

83
Q

Mutation cause I

A

Error in replication
DNA polymerase slippage causes indels during replication: usually of repeated regions

84
Q

Mutation cause II

A

Nucleotide mispairing
Energetically favorable hydrogen bonding ensures DNA strand complementarity

85
Q

Ionization

A

Gain or loss of an electron

86
Q

Mutation cause III

A

Cellular environment
Depurination
Deamination
Oxidative Damage

87
Q

Depurination

A

Loss of a purine base (G or A)
Efficiently repaired by endogenous DNA repair mechanisms

88
Q

Deamination

A

removal of an amine (-NH2) group from C, A and G
Can alter base pairing

89
Q

Oxidative Damage

A

Reactive Oxygen Species (ROS) [H2O2, O2-, OH-]: byproducts of aerobic metabolism in mitochondria, induced by ionizing radiation
Damages DNA: creates mismatched base pairing, by directly breaking DNA double strands

90
Q

Mutagen

A

A chemical or physical force that can increase the mutation rate above background

91
Q

Mutagens can:

A

a) replace a base pair in the DNA strand.
b)chemically alter a base pair leading to a mismatch
c) damage a base pair such that it cannot base pair with any other nucleotide

92
Q

Type of mutagens

A

Chemical agents: alkylating agents, ROS, intercalating agents, DNA adducts, Base analogs
Physical agents: UV/ionizing radiation

93
Q

Alkylating Agents

A

Addition of an alkyl group (usually CH3 or C2H5) to a nucleotide.
disrupts correct base pairing

94
Q

Bulky adducts

A

Attach nitrogenous bases: removal of the adduct causes apurinic site-mutation

95
Q

Base Analogs

A

Chemically similar to A,C,T,G
Can be incorrectly incorporated by DNA polymerase
Can be mutagenic if analog is likely to mispair

96
Q

Intercalating agents

A

Inserts between base pairs
Distorts double helix
Increases DNA polymerase slippage

97
Q

UV

A

Covalently links neighboring pyrimidines: forms pyrimidine dimers, can’t be recognized by DNA polymerase, stops DNA repliaction
Often results in transition mutations

98
Q

Ionizing Radiation

A

Indirect: causes reactive ozygen species (ROS)
ROS: creates mismatched base pairing, directly breaking DNA double strands( abasic sites, single and double strand DNA breaks)

99
Q

Carcinogens

A

Compounds that can lead to tumor development.
Many induce mutations that de-regulate a cell’s ability to stop proliferating

100
Q

Mutagenicity Ration (MR)=

A

total number of revertants/number of spontaneous revertants
If a compound has not mutagenic effect, MR=1
If a compound shows signs of being mutagenic, MR>1, if a compound kills the cells, MR<1

101
Q

Major DNA repair systems

A

Base excision repair (BER)
Nucleotide Excision Repair (NER)
Mismatch Repair (MMR)
Translesion Synthesis (TLS)
Homologous recombination repair (HR)
Non-homologous end-joining (NHEJ)

102
Q

The modus operandi of DNA repair systems

A

Surveillance(error detection post replication)
Excision(enzyme removes or alters the bp(s) involved)
Polymerization(uses undamaged template/homolog to re-polymerase the removed bases)
Strand ligation (reconnects any sugar-sugar bonds in the repaired strands)

103
Q

Direct repair

A

Some DNA damage can be directly reverted using specific enzymes that identify altered specific nucleotides

104
Q

Base Excision Repair

A

Removes and replaces damaged bases: caused by alkylation, oxidation and deamination.
Relies on complementarity on the non-affected strand to correct the mistake

105
Q

Base Excision Repair steps

A
  1. Detection
  2. Excision
  3. Polymerization
  4. Ligation
106
Q

Nucleotide Excision Repair

A

For large damage affecting multiple base pairs, bulky adducts and pyrimidine dimers

107
Q

Nucleotide Excision Repair Steps

A
  1. Damage detection
  2. Strand separation (helicases)
  3. Incision (endonuclease/nickase)
  4. Excision (20bps)(nuclease)
  5. Polymerization (DNA replication factors and polymerases)
  6. Ligation (DNA ligase)
108
Q

Xeroderma Pigmentosum (XP)

A

Individuals with XP are sensitive to sunlight.
the cells of individuals with XP are deficient in the repair of UV-induced damge to DNA.
NER pathway impaired.
Individuals with XP may develop skin cancer or neurological abnormalities

109
Q

Nucleotide Excision Repair genes

A

XPA, XPB, XPC, XPD, XPE, XPF, XPG

110
Q

Mismatch repair

A

Conserved from bacteria to eukaryotes.
Active during DNA replication
Loss of MMR leads to a 100 fold increase in mutation frequency due to replication errors.

111
Q

Mismatch repair steps

A
  1. Detection
  2. Incision
  3. excision
  4. Synthesis
  5. Ligation
112
Q

Hereditary non-polyposis colorectal cancer (HNPCC)

A

Defects in MMR because of mutations in Msh2/Msh6/Mlh1 and Pms1
Autosomal dominant disorder
Increases predisposition to several cancers because of defects in DNA repair.
Tumor arises when the wildtype copy is lost from heterozygous tissues

113
Q

Double stranded break repair

A

Most cytotoxic damage to DNA
Affects both DNA strands
Cannot use template to repair
repair is critical: can lead to chromosomal abnormalities or cell death.
Also used in meiosis
Two types: homologous recombination, non-homologous end joining

114
Q

Mutations in DSB repair genes

A

lead to a serioes of hereditary neurodegenerative, developmental disorders, immunodeficiencies and cancer predispositions

115
Q

Homologous recombination (HR)

A

Uses homologous chromosome as template
Active post-DNA replication
More error-proof
Used in meiosis to produce recombinant and non-recombinant chromosomes
Used in CRISPR gene editing to introduce precise changes or whole new gene sections

116
Q

Non homologous end joining (NHEJ)

A

DNA strands joined independent of compementarity.
Active in dividing and non-dividing cells
Does not require a template strand
More prone to introducing errors.
Used in CRISPR gene editing to introduce random indels.

117
Q

NHEJ steps

A
  1. Detection
  2. Strand resection
  3. Polymerization
  4. Ligation
118
Q

HR steps

A
  1. Detection
  2. Strand resection
  3. Strand exchange/invasion
119
Q

Synthesis dependent strand annealing pathway (SDSA)

A

Reconstitution of original strand-no crossovers
Excision, polymerization, and ligation all occur together: DNA helicase breaks invading off the homologous template after polymerization, original strnds re-annea
No chance of strand exchnage- no crossovers

120
Q

Polymerase chain reaction

A

PCR
“making and isolating DNA”
An in vitron system to amplify DNA fragments.

121
Q

PCR steps

A
  1. Add reagents together in a tube.
  2. Denature: heat to seperate DNA strands-> 95
  3. Anneal: cool slowly, allowing primers to bind- 60
  4. Extend: heat to working temperature of Taq DNA polymerase- 72
  5. Repeat
  6. Produce exponentially more target
    7…..
  7. Profit
122
Q

Measuring DNA

A

Agarose gel electrophoresis

123
Q

Agarose gel electrophoresis

A

A system to measure and seperate DNA fragments.
DNA is negatively charged: migrates towards the positive pole: running an electric current through the gel moves DNA.
DNA fragments will seperate from each other based on size (bp): long DNA fragments migrates slower through dense agarose matrix.
Ladder is run along side to determine band size.
Can be used to detect the presences of specific DNA. can be used for genotyping.

124
Q

Plasmid vectors

A

Cicular, double stranded DNA molecules present in bacteria.
Range from 1 kb to over 200 kb.
Possible foreign/recombinant DNA insert up to 10kb
Replicate autonomously
Many carry antibiotic resistanct genes, which can be used as selectable markers.

125
Q

In vivo

A

in life

126
Q

Gene cloning

A

isolation and amplification of a given gene; introducing a desired DNA molecule into a viable host molecule
Creates a recombinant molecule that can be introduced and propagated in vivo inside a host cell
Can be extracted and purified

127
Q

Recombinant DNA molecule

A

two or more different DNA strands joined together

128
Q

Essential assets of an engineered plasmid for gene cloning

A
  1. Ori
  2. Amp^R
    3.Polylinker/multiple cloning site
129
Q

Ori

A

origin site of replication.
Allows plasmid replication independently of bacterial chromosomal DNA
Must replicate in live bacteria

130
Q

Amp^R

A

Selective marker
Allows for selection of only bacteria that carry it
Ampicillin resistance
must be selected on live bacteria

131
Q

POLYLINKER/multiple cloning site

A

Specific location for inserting DNA of interest.
Unique restriction digest sites.
Must allow for several options for safe cloning of inserts.

132
Q

Phages

A

modified viral DNA

132
Q

Plasmids

A

modified small bacterial non-chromosomal DNA

133
Q

Growth Hormone Deficiency (GHD)

A

Pituitary makes insufficient amounts of gorwth hormone.
Children with GHD have short stature and delayed sexual maturity.
Treament requires supplementation with Human growth hormone (HGH).
Used to use human cadavers until 1980s.
Synthetic HGH produced in genetically modified bacteria

134
Q

Producing human growth hormone in bacteria requires

A
  1. Precise (directional) cloning of the coding sequence of the human gene (cDNA)
  2. Downstream of a bacterial promoter and sequences required for translation
135
Q

Selections Strategies in Cloning:

A

(1) selection for plasmid: ensure that the only bacteria with the plasmid survives, antibiotic resistance
(2) Selection for insert: identify bacteria with recombinant plasmids (has insert), blue/white selection

136
Q

Genetic engineering

A

The use of recombinant DNA technology to alter an organism’s genotype

137
Q

Transgene

A

genetically engineered DNA to be introduced to a genome

138
Q

Transgenic organism

A

Organism that contains a transgene

139
Q

Genetically modified organism (GMO)

A

organism that is genetically engineered. Used more frequenctly in the context of commercial organisms.

140
Q

Genetic engineering can be used for

A

Biotechnology
Research

141
Q

Bioinformatics

A

Annotating whole genome sequencing

142
Q

Homologous genes

A

Share a common ancestor and display significant sequence conservation

143
Q

Orthologs

A

Homologous genes that are synthetic
Located in the same genetic locus in closely related species

144
Q

Paralogs

A

Homologous genes that evolved as duplicates
Genes often duplicate as genomes evolve
Arose from a gene duplication in a common ancestor

145
Q

Pseudogenes

A

relics that reveal evolutionary ancestry

146
Q

Catabolic pathways

A

Breakdown substrates, induction of enzyme synthesis

147
Q

Anabolic pathways

A

Builds products
Repression of enzyme stimulus

148
Q

Inducible systems

A

off by default

149
Q

Repressible systems

A

on by default

150
Q

The lac operon

A

Is transcribed only in the presence of lactose and cAMP-CAP.
Normally inactivated-off
Saves energy
Lactose ins the inducer: induces transcription, inactivates repressor

151
Q

The trp Operon

A

A repressible system
Synthesizes the amino acid tryptophan
If there is no trp, then the trp codons can’t get translated

152
Q

Enhanceosome

A

large protein complex that acts synergistically to active transcription

153
Q

Insulator

A

cis-element that restricts enhancers: sometimes called a silencer

154
Q

Chromatin remodeling

A

the process of changing histone position
Helps transcription by moving histones blocking the prmoter, enhancers, etc.

155
Q

Epigenetics

A

is heritable traits excluding DNA sequence: based on ‘parental’ ‘environment=lamarckian

156
Q

Population

A

A group of individuals on the same species in the same place and time

157
Q

Population genetics

A

Studies how alleles “flow” down generation in a population.
Attempts to make sense of evolutionary trends.

158
Q

Haplotypes

A

The combination of alleles from multiple loci that segregate together

159
Q

A gene pool

A

The sum of all alleles present in the breeding members of a population at a given time,

160
Q

Hardy-Weinberg principle (HWP)

A

Expresses a mathematical relationship between allelic and genotypic frequencies
Can predict genotypic frequencies in an “ideal” population based on the allele frequencies and vice versa.

161
Q

Ideal populations are

A
  1. Infinite in size (no inbreeding)
  2. Have random mating (no sexual selection)
  3. All genotypes are equally fit (no differential death)
  4. No migration (no external influence)
  5. No mutations (no new alleles)
    Allele frequencies will not change
    Only exist in theory
162
Q

Positive mating

A

like attracts like

163
Q

Disassortative mating

A

Opposites attract

164
Q
A

BIO 226 (4 decks)

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