Exam 4 Flashcards
Do organisms contain the same genes throughout development?
Yes: every somatic cell has the same genome
What makes cells have different functions?
Different proteins are in different cells
How can polymerase copy DNA if it is all wrapped up?
Acetylation
What is acetylation
Histones have tails that interact with the acetyl group to loosen the packing allowing the DNA to be exposed
What is methylation?
Histones interact with methyl and the DNA stays packed
What is epigenetics?
A heritable change that does not change the nucleotides in the genome but does change the expression of genes (environmental agents, trauma, stress, famine, obesity can pass on to offspring)
What are transcription factors?
Protein-based regulation. Proteins initiating or regulating transcription
What are general transcription factors (TFs)
Initiation complex: TATA box protein and TAF accessory factors
What are enhancer sites?
It is a promoter that loops or bends DNA allowing RNA synthesis
What are specific transcription factors
time and tissue
How do different types of regulations occur
Coordinate expression: Different combinations of genes allow for different regulations
What is alternative splicing?
Splisosomes in different cells can splice pre-mRNA differently causing different types of proteins to be produced from the same genetic material.
What are small interfering RNA (siRNA)?
They create a perfect complement to RNA to degrade RNA later
What are micro (miRNA)?
They are an imperfect fit for RNA to inhibit translation
What is the RISC protein complex?
What does CRISPR stand for?
Clustered, regularly interspaced, short, palindromic, repeats
What is bioremediation?
Using a biological system to remove pollutants from an ecosystem
What is gene therapy?
Providing a normal copy of a gene to a person who has a defective copy of that gene
What is Ex-vivo gene therapy?
It means outside of life. taking cells from a patient, changing them, then returning them to their body.
What is In-vivo gene therapy
it means inside of life. Directly adding treatment, that did not originally come from the organism, into patients.
What is germline modification?
Editing a human while they are a single-cell embryo so that as they grow up every cell is edited including their germ cells
What is microevolution?
Change in allele frequency over time happening within a population or species
What is macroevolution?
Descent with modification
What are some ways we can see evolution?
Fossils
What is isotope dating?
Isotopes decay from unstable to stable at a given rate. This rate of decay can be used to determine how old a fossil is.
What are evolutionary features that are evidence of anstresial traits?
Vestigial structures
What are homologous traits?
Traits shared in different species because it was present in the common ancestor
What is convergent evolution?
Common selective pressures lead to similar traits evolving independently
What are species?
A species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring
How are species determined?
Something that blocks the gene flow from different populations. They will have different allele frequencies, possibly different phenotypes and instincts, and can’t reproduce together.
What is a hybrid species?
A hybrid species is the offspring of two different species or subspecies that have mated or cross-pollinated.
What are the Prezygotic Isolation Mechanisms?
- Ecological isolation
- Behavioral isolation
- Temporal isolation
- Mechanical isolation
- Gametic Isolation
What are Postzygotic Isolation Mechanisms?
Zygotes being blocked from developing into normal reproductive adults
What are Prezygotic Isolating Mechanisms?
Gametes blocked from coming together to create a zygote
When do Postzygotic isolation mechanisms occur?
After fertilization
What occurs from Postzygotic Isolation mechanisms?
hybrids will form, but will be inviable, infertile, or have lower fitness
What keeps 2 individuals reproductively isolated?
Prezygotic Isolation and Postzygotic isolation
What are the Prezygotic Isolation factors?
Ecological, Behavioral, Temporal, Mechanical, Gametic
What is one factor that can lead to speciation?
Natural Selection
How do species form?
Populations must diverge and reproductive isolation must evolve (genetic drift or natural selection then geneflow)
What is Allopatric Speciation?
The geographic separation of populations
What is Vicariance?
A barrier that arises within an existing population causes speciation (population exist before barrier)
What is Dispersal?
Individuals crossing an existing barrier then evolve separately from the original group (barrier exists before population)
What is sympatric Speciation?
Speciation without geographic isolation
What is Ployploidy
There are extra sets of chromosomes causing instantaneous isolation.
What is Allopolyploidy?
Hybridization between species
Different chromosomes
What does non-random mating cause?
Disruptive sexual selection
What is Autoployploidy?
Error is meiosis nondisjunction
What is Habitat Differentiation?
Different use of the local habitat with a non-overlapping territory.
What are all of the Allospatric Speciation factors?
Vicariance and Dispersal
Why can genomes change over time?
Single base pair changes, gene duplications, genome duplication, transposable elements, structural changes
What determines genome size?
amount of DNA
What are the components of the genome?
~75% non-coding repetitive DNA and the rest coding
What are transposable elements>
“jumping genes” are elements that move in the gene that cause a different expression of the gene
Is DNA mobile?
Yes, about 50% of DNA is mobile and is known as TEs
What is the “cut and paste” mechanism?
Transposase cuts out DNA and reinserts the transposon (the new mobile element) somewhere else in the genome
What is the “copy and paste” mechanism?
A copy of DNA is created and the transposon (new mobile element) is copied and inserted somewhere else
What are the difference between retrotransposons and transposons?
Retrotransposons are the RNA intermediate that transposons code for reverse transcriptase. This is done to get a copy of the original DNA to add somewhere else in the genome.
What are the consequences of Transposable Elements?
If inserted in an intron nothing will occur. If inserted in an exon different sequences will occur and cause mutations. Unequal crossing over can occur in the recombination of homologous chromosomes as well.
Where do TEs From from?
Viruses
What is needed to be a virus?
A nucleic acid in the middle with a protein coat. This is not a cell.
What are the two structures of viruses?
Helical (protein spiral) or icosahedral (dice shaped with additional spindles)
How do Viruses replicate?
- Attach to host
- Enter & transfer DNA/RNA
- Make new viral parts
i. Replicate DNA/RNA
ii. Synthesize proteins - Self-assemble into new viruses
- Exit host
What are some defense systems against viruses?
Immune cells and antibodies
What is coevolution?
Reciprocal genetic change in interacting species owning to natural selection imposed by each other
Why do stomatic cells have different gene expressions even when they have the same genome?
Different proteins are in different types of cells and at different stages of development
How is chromatin organized?
DNA: organized around
Histones: organized into
Nucleosomes: compacts into
Chromatin
How can polymerase
make a copy if DNA is
all wrapped up?
Unpack the DNA through Acetylation
What is Acetylation?
Packing around the histone loosens
What is methylation?
The tightening of the DNA around Histones
What is Epigenetics?
A heritable change that does not change the underlying sequence of
DNA, but does change the expression of genes (Environmental agents, Trauma & stress, Famine & Obesity)
What does siRNA do?
Degrade RNA
What does miRNA do?
Inhibits translation
What does Ubiquitin do?
Marks protein to be destroid
What does Proteasome do?
Degrade polypeptides
What is Random Mutagenesis?
Creating a large library of collection of mutants
What is Site-Directed Mutagenesis?
Specifically, create a single point ofa mutant of interest
What’s a drawback of library mutagenesis?
if you don’t know what you’re looking for or there’s little
research out there on your gene of interest, it could be useful to do
this random mutagenesis
What are the Drawbacks of site-directed mutagenesis?
You want to use this technique when you have at least
some idea of a specific region of interest in your gene, or if there’s a
a lot of research has already been done on your gene
What is Gene ontology?
A chart that tells you the function of genes
How does the gene expression profile change over time in an organism?
Higher and lower reads over time
What does CRISPR stand for?
Clustered, Regularly Interspaced, Short, Palindromic Repeats
What is Bioremediation?
Using a biological system (like bacteria, fungus,
etc.) to remove pollutants from an ecosystem
What does Transgenic mean?
adding DNA from a
different organism into another (like
adding a pepper gene into a banana)
What is Gene Therapy?
Providing a normal copy of
a gene to a person who has a defective copy of that gene
What is Ex-vivo gene therapy?
Outside of life. Taking cells from a patient, changing them,
then returning them
What is in-vivo gene therapy?
Inside of life. Directly adding the treatment to the patient
What is Germ Line Modification?
Editing a human while they are a single-cell embryo, thus, they grow up to have every cell edited
Which type of gene mutations will be passed to offspring?
germline
What is a ”population”?
A group of individuals of the same species that live in the same area and interbreed
What are allele frequencies?
measures how many out of the total population
What is evolution?
The change in allele frequencies over time
Do individuals evolve?
NO: populations evolve over time
What is Gene Flow?
Movement of Allele among populations
What is nonrandom mating?
Mating based on phenotype/genotype
What is genetic drift?
Changes in allele frequencies due to random chance
What is natural selection?
Adaptive alleles to survive
What is Assortative Mating?
Homozygous mating
What is Disassortive Mating?
Heterozygous mating
What is bottlenecks?
severe reduction in the size of a population and its
genetic variation (often due to a drastic event)
What are founder events?
a population is started by just a few individuals
What is artificial selection?
Breeder selects desired (advantageous) traits
What is natural selection?
The environment selects for advantageous traits
What are adaptations?
Traits that confer an advantage in a given environment
What is sexual dimorphism?
phenotypic difference based on sex
What is Directional Selection?
phenotype of one extreme is favored so allele frequencies shift in that direction
What is Stabilizing Selection?
Intermediate phenotype is favored
and alleles frequencies move toward the mean
What is Disruptive Selection?
Both extreme phenotypes are favored. Alleles frequencies of extremes increase
What is Frequency-dependent selection?
Phenotypes are favored based on how common or rare they are
How do evolution mechanisms interact?
Mutation CREATES variation
Natural selection SORTS variation
Drift ELIMINATES variation
Gene flow RESTORES variation
What is Phylogenetics?
the study of
evolutionary relationships
What is biogeography?
the geographical distribution of plants and animals.
What is geographic variation?
Species can vary among
populations with intermediates
at boundaries
What is a species?
a group of populations whose members have the
potential to interbreed in nature and produce viable, fertile offspring
What is the morphological Species concept?
distinguished by phenotypic traits
What is the Ecological Species concept?
distinguished by ecological roles or
niches
What is the phylogenic species concept?
distinguished by the smallest group of organisms that share a common ancestor
What is the biological species concept?
a species is a group of populations whose members have the
potential to interbreed in nature and produce viable, fertile offspring
