Term
| The Bighorn sheep lost genetic variation due to what? |
|
Definition
genetic drift
-the introduction of sheep from other populations
-decrease in population due to habitat destruction, competition with domestic animals, diseases, & trophy hunting |
|
|
Term
|
Definition
| the chance tendency of one allele to become more frequent in the population, loss of genetic variation |
|
|
Term
| Is lots of homozygosity good or bad? |
|
Definition
|
|
Term
| Why is genetic diversity good? |
|
Definition
| it allows a population to adapt to changes in the environment |
|
|
Term
| In Peter Buri's experiment with the fruit flies, what did he conclude about the effect of genetic drift on the genetic composition of populations? |
|
Definition
-as a result of genetic drift, allelic frequencies in different populations diverge and often become fixed for one allele or the other
-originally frequency: 0.5 to 0.5 (equal frequency)
-ending frequency: 1 to 0 (one fixed allele) |
|
|
Term
| What is a bottleneck effect? |
|
Definition
when a population decreases and only a few alleles can pass through the tiny population, resulting in genetic drift and/or fixed alleles
Ex. Cheetahs (almost all identical)
Northern elephant seals
Bison |
|
|
Term
|
Definition
| a group of organisms that can interbreed in nature and produce fertile offspring |
|
|
Term
|
Definition
| the members of one species in the same location and time that interbreed and shuffle their genes together |
|
|
Term
|
Definition
-all the alleles of all the genes present in an interbreeding population
-through succeeding generations the pool is shuffled
-each new zygote "draws out" 2 copies of each gene locus |
|
|
Term
| What is population genetics? |
|
Definition
| the study of the genetic composition of populations, and how a population's collective group of genes changes over time |
|
|
Term
| What are Hardy and Weinberg credited with? |
|
Definition
the idea and mathematical equation that formed the basis of population genetics
-p+q=1 |
|
|
Term
| Is the Hardy-Weinberg Law actually a scientific law? |
|
Definition
| no, it is a model (a static baseline) to compare real life data against |
|
|
Term
| What does the Hardy-Weinberg law say? |
|
Definition
| The relative frequency of alleles of a gene tends to stay the same (at equilibrium) from generation to generation through time |
|
|
Term
In the H-W law, what does p+q=1 represent?
What does p^2 + 2pq + q^2=1 represent? |
|
Definition
-allelic frequencies
-genotype frequencies |
|
|
Term
In the H-W law, what does the p^2 represent?
What does the q^2 represent?
What does 2pq represent? |
|
Definition
-the homozygous dominant genotype
-the homozygous recessive genotype
-the heterozygous genotype |
|
|
Term
| In the H-W law, why must one multiple the heterozygote genotype (pq) by 2? |
|
Definition
because there are 2 ways in which one could receive the heterozygous genotype from their parents
-"A" from mother and "a" from father-->Aa
OR
-"a" from mother and "A" from father-->Aa |
|
|
Term
| What assumption does the H-W law make, causing it to be a standard rather than a realistic law? |
|
Definition
-large population
-mating is random
-not affected by mutation
-no migration
-no natural selection |
|
|
Term
| How can the H-W equilibrium be used? |
|
Definition
| like a null hypothesis to compare actual data to determine if a population is static |
|
|
Term
| When the H-W hypothesis is rejected, what does it often mean? |
|
Definition
| one allele is superior over the other allele for survival and reproduction, and that natural selecting is occurring |
|
|
Term
| What is the basis of microevolution? |
|
Definition
| changes in allele frequency |
|
|
Term
| What is heterozygote superiority? |
|
Definition
Ex. sickle cell anemia
-when a person is homozygous, allele causes sickle cells
-however, the heterozygous individuals for the allele survive both malaria and sickle cell and reproduce |
|
|
Term
| What is inbreeding called and does it increase homozygosity or heterozygosity? |
|
Definition
-consanguinity
-increases homozygosity |
|
|
Term
|
Definition
| genetic change taking place in a population, what evolves is the gene pool |
|
|
Term
| What are the 2 steps to evolution? |
|
Definition
1. mutation & recombination produce new alleles and combinations
2. new change may increase in frequency by chance genetic drift or by natural selection |
|
|
Term
| Are the traits that a species need what evolves? |
|
Definition
| NO-mutations are purposeless, natural selection determines which changes survive in a certain environment |
|
|
Term
| What are the advantages of molecular data? |
|
Definition
-molecular data are genetic
-molecular methods can be used by all organisms
-molecular methods can be applied to a huge amount of genetic variation
-all organisms can be compared with the use of some molecular data
-molecular data are quantifiable
-molecular data often provide info about the process of evolution
-the database of molecular info is large and growing |
|
|
Term
|
Definition
| evolution within a lineage with the passage of time |
|
|
Term
|
Definition
| the splitting of one lineage into two |
|
|
Term
| How can RFLPs be used to study evolutionary genetics? |
|
Definition
can be used by comparing restriction sites among different individuals of a species to see the genetic structure of a population & assess the evolutionary relationships among organisms
Ex. African elephant-showed that elephant populations are genetically differentiated across Africa |
|
|
Term
| How can microsatellites be used to study evolutionary genetics? |
|
Definition
microsatellites (STRs whose number of repeats are unique to individual organisms) can be amplified with PCR, then run through electrophoresis and banding patterns can be studied for genetic variation, genetic relationships, and population genetic differences
Ex. bighorn sheep-showed that sheep are actually getting smaller due to selective pressure on horn size for trophy hunters |
|
|
Term
| What is allopatric speciation? |
|
Definition
speciation (process in which new species arise) by a geographic barrier that splits a population into 2 or more groups & prevents gene flow between them
-genetic differences are acquired over time due to selection, genetic drift, mutations
-Reproductive isolation mechanisms arise
-2 new species
Ex. Darwin's finches |
|
|
Term
| What is sympatric speciation? |
|
Definition
speciation that arises in the absence of any geographic barrier, RIMs evolve in a single interbreeding population
-debatable
Ex. apple maggot fly |
|
|
Term
| How can speciation occur through polyploidy? |
|
Definition
-typically arises when 2 diploid species hybridize, producing 2N hybrid offspring that are still fertile and reproduce
-numerous in angiosperms
Ex. European salt grass+American salt grass=S. anglica
Ex. |
|
|
Term
| What is a phylogenetic tree? |
|
Definition
| a graphical representation of the evolutionary relations among a group of organisms |
|
|
Term
| Prokaryote cell reproduction |
|
Definition
-simple division: separation of replicated circular chromosome
-origin of replication
-high rate of replication |
|
|
Term
| eukaryotic cell reproduction |
|
Definition
-homologous pair
-cell cycle
-genetic consequences |
|
|
Term
|
Definition
| attachment point for spindle microtubules |
|
|
Term
|
Definition
| tips of a linear chromosome |
|
|
Term
| How are metaphase chromosomes classified? |
|
Definition
| by the position of the centromere (metacentric, submetacentric, acrocentric, & telocentric) |
|
|
Term
|
Definition
| extended period between cell divisions, DNa synthesis and chromosome replication phase |
|
|
Term
|
Definition
| consists of mitosis and cytokinesis |
|
|
Term
|
Definition
| separation of sister chromatids |
|
|
Term
|
Definition
|
|
Term
|
Definition
| stage in mitosis in which chromosomes condense (each chromosome has 2 chromatids) & mitotic spindle forms |
|
|
Term
|
Definition
| nuclear membrane disintegrates, spindle microtubules attach to chromatids |
|
|
Term
|
Definition
| chromosomes line up on metaphase plate |
|
|
Term
|
Definition
| sister chromatids separate and move toward opposite poles |
|
|
Term
|
Definition
| chromosomes arrive at spindle poles, nuclear membrane re-forms, chromosomes relax |
|
|
Term
| What are the genetic consequences of the cell cycle? |
|
Definition
-2 new genetically identical cells
-new cells have full complement of cells
-each new cell contains app. half of cytoplasm and organelles from parental cell |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| cell prepares for mitosis |
|
|
Term
|
Definition
| separation of homologous chromosome paris and reduction of chromosome number by half |
|
|
Term
|
Definition
| separation of sister chromatids (equational division), very similar to mitosis |
|
|
Term
|
Definition
| synapsis, forming a tetrad, crossing over |
|
|
Term
|
Definition
| random alignment of homologous paris of chromosomes along metaphase plate |
|
|
Term
|
Definition
| separation of HOMOLOGOUS PAIRS (not sister chromatids like in mitosis & meiosis 2) and random distribute into cells |
|
|
Term
| What are the genetic consequences of meiosis? |
|
Definition
-four cells from each original cell
-chromosome number reduced by 1/2 (haploid)
-new cells are genetically different from each other and parent |
|
|
Term
|
Definition
| protein that holds chromatids together |
|
|
Term
|
Definition
-2,000 years ago
-made observations of genes changing over time, wrote on walls |
|
|
Term
|
Definition
| began dissecting the brain, led to belief that brain was site of perception & semen, led to pangenesis |
|
|
Term
|
Definition
| people believe that certain particles carried genetic material to reproductive organs from which they are passed to offspring at conception |
|
|
Term
| inheritance of acquired characteristics |
|
Definition
| all characteristics that are gained during life are passed on |
|
|
Term
|
Definition
| keenly interest in heredity, rejected pangenesis and inheritance of acquired characteristics |
|
|
Term
|
Definition
| developed a # of techniques for plant and animal breeding, but little had to do with heredity |
|
|
Term
|
Definition
| discovered cells in 1665, gave rise to preformationism |
|
|
Term
|
Definition
| inside an egg or sperm is a tiny person that grows, all characteristics come from one person |
|
|
Term
|
Definition
| no dominance or recessiveness, traits just blend |
|
|
Term
|
Definition
-1676
-came up with idea that plants reproduce sexually using pollen, led to crossing plants and creating hybrids |
|
|
Term
|
Definition
-1800s
-3 Parts: 1) all life is composed of cells 2) cells arise only form preexisting cells 3) cell is fundamental unit of structure & function |
|
|
Term
|
Definition
| cells in reproductive organs carry a complete set of genetic info that is passed to the egg or sperm |
|
|
Term
|
Definition
-1902
-genes are located on chromosomes |
|
|
Term
|
Definition
| -studied fruit flies and looks at mutations, which unraveled much of transmission genetics |
|
|
Term
|
Definition
| came up with DNA model in 1953 |
|
|
Term
|
Definition
-1983
-developed a technique to look at pieces of DNA & make multiple copies of it (PCR) |
|
|
Term
| First complete DNA sequence of a free-living organism and in what year? |
|
Definition
-Haemophilus influenza (italicized)
-1995 |
|
|
Term
|
Definition
|
|
Term
|
Definition
| loss of both member so of a homologous pair (2n-2) |
|
|
Term
|
Definition
| loss of 1 chromosome (2n-1) |
|
|
Term
|
Definition
| gain of a single chromosome (2n+1) |
|
|
Term
|
Definition
| gain of both members of a homologous pair (2n+2) |
|
|
Term
|
Definition
| extra SET of chromosomes all from a single species |
|
|
Term
|
Definition
| extra set from two species |
|
|
Term
| What are the 3 main types of chromosomal mutations? |
|
Definition
-rearrangements
-aneuploids
-polyploids |
|
|
Term
| What 4 types of chromosomal rearrangements? |
|
Definition
-duplication
-deletion
-inversion
-translocation |
|
|
Term
| What are the 4 types of aneuploidy? |
|
Definition
| nullisomy, monosomy, trisomy, and tetrasomy |
|
|
Term
| What are the 2 types of polyploidy? |
|
Definition
-autopolyploidy
-allopolyploidy |
|
|
Term
| Mendel's Law of Segregation |
|
Definition
| states that each diploid organism contains 2 alleles for a gene and that a gamete receives one of the 2 alleles |
|
|
Term
When do you use the multiplication rule for probabilities?
When do you use the addition rule? |
|
Definition
-multiplication: 2 or more independent events, "and"
-addition: 2 exclusive events, "or" |
|
|
Term
| What type of individual to you cross with your unknown genotype in a testcross? |
|
Definition
|
|
Term
|
Definition
| crossing a F1 genotype with one of the parental genotypes |
|
|
Term
|
Definition
crosses in which phenotypes of male and female are reversed
Ex. tall male w/short female & short male w/tall female |
|
|
Term
|
Definition
-1982
-proposed that peptic ulcers are caused by H. pylori
-won Nobel prize in 2005 |
|
|
Term
|
Definition
-1946
-demonstrated that bacteria can transfer & recombine genetic info
-auxotrophs were mixed and a few were then able to grow on min. medium
-did not realize then that conjugation was taking place |
|
|
Term
|
Definition
-followed Lederberg and Tatum's experiment
-u shaped tube with filter, no bacteria could pass
-concluded that bacteria must touch to exchange genetic info (conjugation) |
|
|
Term
|
Definition
| cells that take up DNA through their outer membranes in transformation |
|
|
Term
|
Definition
| transfer of genes from one organism to another by a mechanism other than reproduction (such as transformation or transduction) |
|
|
Term
|
Definition
-first described by Theodore Escherich in 1885
-small genome: 1 chromosome, 4300 genes, 4, 638, 858 bp
-reproduces every 20 minutes
-easy to culture
-prototrophic, min. medium with glucose & inorganic salts
-reproduces through simple binary fission
-haploid genome makes mutations easy to isolate |
|
|
Term
|
Definition
| inactive phage that has been incorporated into bacterial DNA in the lysogentic cycle |
|
|
Term
| What are the 3 methods for mapping genes? |
|
Definition
-interrupted conjugation
-transformation
-transduction |
|
|
Term
|
Definition
| RNA viruses capable of integrating into genomes of their host, uses reverse transcriptase |
|
|
Term
|
Definition
| DNa copy of viral DNA or RNA, integrated into host chromosome and replicated along with the host chromosome |
|
|
Term
| All retroviruses contain which 3 genes? |
|
Definition
|
|
Term
|
Definition
-first recognized in 1982
-Robert Gallo: proposed AIDS is caused by retrovirus
-AIDS caused by 2 immunodeficiency viruses: HIV-1 & HIV-2
-attacks and destroys helper T cells
-people die from secondary infections
-9749 nucleotides long
-vaccine is hard to develop bc reverse transcriptase causes so many mutations that quick evolution occurs |
|
|
Term
|
Definition
| science of classification |
|
|
Term
|
Definition
| study of evolutionary relationships |
|
|
Term
|
Definition
| -1868-1869, extracted weakly acidic, phosphorous rich material from nuclei of leukocytes-->nuclein |
|
|
Term
| What are the 3 components of a nucleotide? |
|
Definition
| sugar (deoxyribose or ribose), phosphate, nitrogenous base (A,T,G,C) |
|
|
Term
| Avery, MacLeod, & McCarty |
|
Definition
-discovered that DNA is the substance that undergoes transformation
-concluded this by using enzymes (protease, RNAse, DNAse) to destroy components, culture treated with DNAse did not transform so they concluded that DNA was transforming principle |
|
|
Term
| Avery, MacLeod, & McCarty |
|
Definition
-discovered that DNA is the substance that undergoes transformation
-concluded this by using enzymes (protease, RNAse, DNAse) to destroy components, culture treated with DNAse did not transform so they concluded that DNA was transforming principle |
|
|
Term
|
Definition
-determined that the DNA-not protein-was the genetic material in bacteriophages
-labeled protein coat and DNA of bacteriophage with isotopes, let the phages infect E.coli and reproduce, and examined whether protein coat or DNA of progeny was radioactive |
|
|
Term
|
Definition
| came up with X-ray defraction |
|
|
Term
|
Definition
| found RNA was genetic material in a plant virus (Tobacco Mosaic Virus) |
|
|
Term
| What are purines and do they have a single or double ring structure? |
|
Definition
| A & G, double ring structure |
|
|
Term
| What are pyrimidines and do they have a single or double ring structure? |
|
Definition
| T & C, single ring structure |
|
|
Term
| What are the 3 forms of DNA? Briefly explain. |
|
Definition
-B-DNA: most stable, predominate structure, plenty of water, right-handed structure
-A-DNA: exists if less water is present, right-handed structure, shorter and wider than B-DNA
-Z-DNA: left-handed, occurs in high salt solution |
|
|
Term
|
Definition
| secondary structure of DNA that occurs when sequences of nucleotides on the same strand are inverted complements |
|
|
Term
| What were the 3 models initially proposed for DNA replication? Which is correct? |
|
Definition
-semi-conservative replication (correct): 2 nucleotide strands separate, each serving as a template for new strands
-conservative: entire DNA molecules serves as template, original strand fully conserved
-dispersive: both strands break into fragments that are templates, and then reassemble |
|
|
Term
|
Definition
| determine that semiconservative replication is the correct model, used equilibrium density-gradient centrifugation to distinguish between heavy DNA and lighter DNA |
|
|
Term
|
Definition
| occurs in bacteria, unwinding of circular DNA, can occur in a bidirectional pattern |
|
|
Term
| Rolling-circle replication |
|
Definition
| occurs in F factor and some viruses, outside strand is broken and nucleotides are added using inside strand as template, not bidirectional |
|
|
Term
| What are the 5 types of eukaryotic DNA polymerase? Briefly explain the role of each. |
|
Definition
alpha-makes RNA primer and then adds a few nucleotides
beta-does not participate in replication, involved in repair and recombination
gamma-replication and repair of mitochondrial DNA
-delta-leading & lagging strand synthesis, DNA repair, translesion DNA synthesis
-epsilon: leading strand synthesis |
|
|
Term
|
Definition
| binds to origin and separates strands of DNA to initiate replication |
|
|
Term
|
Definition
| unwinds DNA at replication fork |
|
|
Term
| single-strand-binding proteins |
|
Definition
| attach to single strands once DNA is unzipped to keep it from going back together or form secondary structures |
|
|
Term
|
Definition
| causing nicks and reseals DNA to release torque that builds up from unwinding |
|
|
Term
|
Definition
| main polymerase in bacterial cells, elongates nucleotide strand |
|
|
Term
|
Definition
| polymerase in bacterial cells that removes RNA primers and replaces them with DNA |
|
|
Term
|
Definition
| joins Okazaki fragments by sealing nicks |
|
|
Term
|
Definition
-piece of DNA that encodes an RNA molecule and the sequences necessary for its proper transcription
-contains a promotor, RNA-coding region, and a terminator |
|
|
Term
| What five units make up the core enzyme (also called RNA polymerase) in bacterial cells? |
|
Definition
-2 copies of alpha
-1 beta
-1 beta prime
-1 omega-not essential, just helps stabilize the enzyme |
|
|
Term
|
Definition
| a subunit involved in bacterial transcription that binds to the core enzyme, forming a holoenzyme, which allows it to bind to the promotor & start transcription |
|
|
Term
|
Definition
| the initial product of transcription in EUKARYOTIC cells only, then introns are spliced out and exons remain (mRNA) |
|
|
Term
| Of the 5 types of eukaryotic RNA polymerases, which is the main polymerase? |
|
Definition
| RNA polymerase II, transcribes the pre-mRNA |
|
|
Term
| What are the 3 main steps in transcription? |
|
Definition
-initiation
-elongation
-termination |
|
|
Term
| basal transcription apparatus |
|
Definition
| transcription apparatus in eukaryotes, includes RNA polymerase (I,II,or III) and accessory proteins (instead of sigma factor) |
|
|
Term
| How does termination in eukaryotic cells using RNA polymerase II differ from prokaryotic termination? |
|
Definition
-eukaryotic termination uses an enzyme (Rat1) to "chew up" the RNA molecule
-prokaryotic termination involves either Rho-dependent termination (Rho attaches to RNA and causes termination) or Rho-independent termination (terminates when a hairpin in RNA & then a string of U's is formed) |
|
|
Term
| What are the 3 consensus sequences found in bacterial promotor regions? |
|
Definition
| -10 consensus sequence (Pribnow box), -35 consensus sequence, and upstream element at -40 to -60 base pairs |
|
|
Term
| What consensus sequence does the core promotor in eukaryotic DNA contain? |
|
Definition
| TATAAA box and is located -25 to -30 bp upstream |
|
|
Term
| What is the regulatory promotor? |
|
Definition
| located immediately upstream of the core promotor in eukaryotic cells, transcriptional activator proteins bind and speed up transcription initiation |
|
|
Term
|
Definition
| site on the ribosome where the tRNA arrives |
|
|
Term
|
Definition
| site on the RNA where the polypeptide grows |
|
|
Term
|
Definition
| exiting site for polypeptide |
|
|
