Term
| Nucleus Characteristics (3) |
|
Definition
-5-10% of cell volume
-Approx. 10 micrometers in diameter
-Typically one per cell |
|
|
Term
| Functions of the Nucleus (3) |
|
Definition
-Storage, replication and repair of genetic material
-Expression of genetic material
-Ribosome biosynthesis |
|
|
Term
| Structure of the Nucleus - 2 parts |
|
Definition
-Nuclear Envelope
-Nuclear content |
|
|
Term
| What is in the nuclear envelope (3) ? |
|
Definition
-Nuclear Membrane
-Nuclear Lamina
-Nuclear Pores |
|
|
Term
| What is in the nuclear content (4) ? |
|
Definition
-Chromatin
-Nucleoplasm
-Nuclear Matrix
-Nucleolus |
|
|
Term
| Nuclear Envelope: Outer membrane vs inner membrane function |
|
Definition
2 Parallel phospholipid bilayers
-Outer membrane binds ribosomes and is continuous with rough ER (RER)
-Inner membrane contains integral membrane proteins that connect to nuclear lamina
-The inter membrane space is continuous with the ER lumen |
|
|
Term
| Functions of the Nuclear envelope (3) : |
|
Definition
1. Separates nuclear content from the cytoplasm
-separates transcription/translation
2. Selective barrier
-allows limited movement of molecules between nucleus and cytoplasm
3. Bind nuclear lamina |
|
|
Term
| The Nuclear Lamina structure: |
|
Definition
1. Thin meshwork of filaments
-lamins (type of intermediate filament)
-approx. 10 nm diameter
-integrity regulated by phosphorylation
2. Bound to inner surface of NE
-via prenyl group linked to lamin polypeptide
-via integral membrane proteins |
|
|
Term
| The Nuclear Lamina Function (2) : |
|
Definition
-Support for the NE
-Attachment sites from chromatin |
|
|
Term
| Mutations in what gene cause Hutchinson-Gilfordd Progeria Syndrome? |
|
Definition
|
|
Term
| Inner and outer membranes of NE fuse at ________ |
|
Definition
|
|
Term
| Nuclear Pore Complex (NPC) |
|
Definition
A protein structure that fills nuclear pores.
-It is a supramolecular complex with 100s of polypeptides
-Fits into pore and reduces functional diameter to approx. 9 nm
-Extends into cytoplasm & nucleoplasm
-Octagonal symmetry |
|
|
Term
| Functions of the Nuclear Pore Complex (2) |
|
Definition
-Passive diffusion of small molecules across NPC
-Regulated movement of larger molecules |
|
|
Term
| Proteins of less than ____________ dalton size are able to diffuse freely in and out of the NPC |
|
Definition
|
|
Term
| Factors needed for Nuclear Import (4) |
|
Definition
-Cargo protein contains a Nuclear Localization Signal (NLS)
-Karyoproteins (transport receptors)
-Energy
-Ran - Small G protein that act as chemical messengers & triggers |
|
|
Term
|
Definition
GTP = switches on
GDP = switches off |
|
|
Term
|
Definition
-NLS receptor
-Heterodimer importin
-Interact with cytoplasmic filaments
-Carried through NPS
-FG repeats
-Interacts with Ran-GTP
-Disasspciates
-b-importin + RanGTP out
-a-importin + exportin out |
|
|
Term
|
Definition
-Mostly proteins and RNA molecules
-Cargo proteins contain a nuclear export signal (NES)
-Exportins (type of karyopherin) bind NES
-Ran-GTP required to assemble export complex
-Exportin-RNP-Ran-GTP complex transported to cytoplasm
-Ran-GTP hydrolysis to Ran-GDP releases cargo |
|
|
Term
|
Definition
Granular Component: contains ribosomal subunits in various stages of assembly
Fibrillar Component: contains DNA encoding for ribosomal RNA
Dense Fibrillar Component: contains nascent pre-eRNA transcripts and proteins |
|
|
Term
| Functions of the Nucleolus |
|
Definition
1) Ribosome biogenesis
-synthesis of rRNA
-rRNA processing
-.... |
|
|
Term
| What is the cytoskeleton? |
|
Definition
| A dynamic network of protein filaments that forms the cellular scaffolding as well as transport system for organelles and vesicles |
|
|
Term
| Cytoskeleton functions (4) |
|
Definition
1. Structural support
2. Intracellular transport
3. Contractility and motility
4. Spatial organization within cell |
|
|
Term
| Three major elements of the cytoskeleton: |
|
Definition
1. Microtubules - hollow, unbranched tubules of tubulin
2. Intermediate filaments - fibrous, various proteins
3. Microfilaments - solid, think branches, actin polymers |
|
|
Term
| Microtubules (MT): How do the ends differ? |
|
Definition
There is a Plus and a Minus end. Plus is fast growing, while the Minus is slow. MT heterodimers align in the same direction (Head to Tail), and this is STRUCTURAL POLARITY
-Structural polarity is important for MT growth/shrinkage and direction of movement of material along MT |
|
|
Term
| What are the two MT associated proteins? 3 Characteristics/function? |
|
Definition
Dynein and Kinesin
-use ATP to generate force
-can move material along MT 'track'
-can generate sliding force between MTs |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| MTs undergo dynamic __________ and ______________ |
|
Definition
|
|
Term
| This leads to rapid turnover of most MTs within cell, and it called _____________ |
|
Definition
|
|
Term
| Shrinkage can occur very rapidly at plus end (termed ___________) |
|
Definition
|
|
Term
| The ___________ is a major site of microtubule organization found in animal cells |
|
Definition
|
|
Term
| Intermediate Filaments (IF) |
|
Definition
-Exclusive to multicellular animals
-provide structural support, mechanical strength
-Stable (compared to MTs or microfilaments)
-Fibrous proteins, contain central a-helical domain |
|
|
Term
| 5 Classes of IFs (give the 3 from notes) |
|
Definition
1. Keratins : epithelial cells
2. Neurofilaments: neurons
3. Lamins: nucleus of all cells |
|
|
Term
| Structure of Intermediate Filaments (3) |
|
Definition
-a-helical domains wrap around each other forming a rope like dimer (coiled coil)
-monomers are aligned in parallel; IF dimers are POLAR molecules
-Dimers associate anti-parallel; assembled filaments are NON-POLAR |
|
|
Term
| Microfilaments + functions(4) |
|
Definition
-Smallest cytoskeletal element
-Polymer of protein actin
Functions:
-maintenance of cell shape
-cell movement
-cytokinesis
-muscle contraction |
|
|
Term
|
Definition
An F-actin associated motor protein
-Most move toward plus end of microfilament
-Divided into two broad groups (conventional and unconventional) |
|
|
Term
| Unconventional myosins... |
|
Definition
| generate force and contribute to motility in non-muscle cells |
|
|
Term
| The Extracellular Space & functions (4) |
|
Definition
extends outwards from the surface of the plasma membrane and contains a variety of secreted materials that influence cellular behaviour
-Mediates cell-cell and cell-extracellular matrix (ECM) interactions
-Provides mechanical protection
-Serves as a barrier
-Binds regulatory factors |
|
|
Term
|
Definition
| organized network of material produced and secreted by cells |
|
|
Term
|
Definition
-composed of cellulose, hemicellulose, pectin and proteins
-Provide structural support to cell and to organism as a whole
-protect cell from mechanical damage and pathogens
-contain biochemical information for cell |
|
|
Term
| Population variation is the ... |
|
Definition
| substrate upon which natural selection acts |
|
|
Term
| Genomes are not __________ |
|
Definition
| deterministic ; interactions of genomes with environment also have an effect |
|
|
Term
| At the heart of genes and genetics is _____ |
|
Definition
| DNA ; deoxyribonucleic acid |
|
|
Term
| Each subunit of NUCLEOTIDE is comprised of (3) |
|
Definition
1. A phosphate group
2. A five carbon sugar
3. One of four cyclic nitrogenous bases |
|
|
Term
| The ______ and ______ nucleotides in polynucleotide chains are connected by _______ _____ |
|
Definition
| Purine; Pyrimidine; phosphodiester bonds |
|
|
Term
| DNA is double-stranded and the strands are ________ |
|
Definition
|
|
Term
| The doube helix is RIGHT or LEFT handed? |
|
Definition
|
|
Term
| The two strands are held together by which two things? |
|
Definition
1. Hydrogen Bonds
2. Hydrophobic interactions |
|
|
Term
| Are DNA strands polar? Yes, or No? |
|
Definition
|
|
Term
| Each strand of DNA has chemical polarity: a __ end and a __ end |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Question: Is 22% of bases are C, what percent is T? |
|
Definition
|
|
Term
| Opposing strands of DNA are said to be _________ |
|
Definition
|
|
Term
| The most common form of DNA is called ... |
|
Definition
|
|
Term
| Two different grooves of different |
|
Definition
| Major groove and Minor Groove |
|
|
Term
| The DNA in living cells is ___________ |
|
Definition
|
|
Term
| The DNA found in ________ and __________ exists in circular chromosomes that resemble those of prokaryotes. |
|
Definition
| Mitochondria and Chloroplasts |
|
|
Term
| Eukaryotic chromosomes are composed of (3) |
|
Definition
|
|
Term
| Nucleosomes with RNA around them in negative supercoil; what doe sit look like? |
|
Definition
| little balls connected with string! The string is linker DNA and there is a nucleosome core (the ball) |
|
|
Term
| The linker region is susceptible to digestion by __________ |
|
Definition
endonuclease
-Enzymes that break stuff down
-We can use these as a tool |
|
|
Term
| DNA is wrapped around a nucleosome core of __ _____ ______ |
|
Definition
|
|
Term
| There are two models that describe the second level of supercoiling: |
|
Definition
The Solenoid and Zig-Zag Models
Solenoid looks kinda parallel, zig-zag just looks really unorganized (when contracted) |
|
|
Term
| The 30 nm fibre is the basic structural unit of the ________ __________ |
|
Definition
| Metaphase chromosome (DNA in its most condensed form) |
|
|
Term
| Third level of condensation - attachment of the 30 nm fibre at many positions to a (non-histone) |
|
Definition
|
|
Term
| QUESTION: How many free 5' ends would be present in one chromosome? |
|
Definition
|
|
Term
| Chromosome ends are protected by ________ |
|
Definition
|
|
Term
| Telomeres provide 3 important functions: |
|
Definition
-Resist degradation by DNases
-Prevent fusion of chromosomal ends (different chromosomes)
-Facilitate replication of the ends of the linear DNA
**cancer cells keep telomeres long and can divide indefinitely |
|
|
Term
| _________ provide the point of attachment of chromosomes to microtubules in the _____ _____ |
|
Definition
| Centromeres; Mitotic Spindle |
|
|
Term
| Three essential regions in a telomere: |
|
Definition
I and II are conserved sequences that bind proteins involved in spindle attachment
Region II is approximately 90% A and T |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Functions of genetic material:
For replication = |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| The evolutionary function |
|
|
Term
| The "transforming principle" |
|
Definition
| This is the mouse example with living type vs heat-killed type (smooth and rough) and how the TRANSFORMED type which is both the types (smooth living and rough heat killed) together killed the mouse, but only the living type WITH a rough outside by itself can kill the mouse. |
|
|
Term
|
Definition
| Cell division; cellular organelles and cytoplasmic contents are divided more or less equally between daughter cells |
|
|
Term
| In Mitosis, nuclear chromosomes must be duplicated... |
|
Definition
| EXACTLY and distributed EQUALLY and EXACTLY to daughter cells |
|
|
Term
| Cell division goes through a set of stages called the ___ _____ |
|
Definition
|
|
Term
| What are the cell cycle stages? (5) |
|
Definition
Gap 1 (G1 phase) - growth, cellular metabolism
S phase - DNA replication
Gap 2 (G2 phase) - Preparation for mitosis
M phase - Chromosomal "pas de deux" and cytokinesis
Interpahse- the time between successive mitoses (G1+S+G2) |
|
|
Term
| Cells that are not actively cycling may exit the cell cycle from G1 and enter a state called ________. These cells are said to be ________. |
|
Definition
|
|
Term
| There is an invariant clock that regulates cell cycle timing. TRUE OR FALSE? |
|
Definition
| FALSE. There is no invariant clock |
|
|
Term
| The ______ cycle in which centrioles are duplicated progresses along with the cell cycle. |
|
Definition
|
|
Term
| In animal cells, what are the microtubule organizing centres? |
|
Definition
| centrosomes; also, the microtubule PLUS end goes outwards from centrosome (might need to know that) |
|
|
Term
| QUESTION: How many chromatids does the human karyotype have? There are 46 chromosomes in the human karyotype. |
|
Definition
|
|
Term
|
Definition
| influences duplicated chromosomes to condense at metaphase |
|
|
Term
|
Definition
| Collection of proteins that acts like a plastic ziptie; it hold sister chromatids together |
|
|
Term
| In Mitosis, is there ever a haploid cell? |
|
Definition
| No! In mitosis, only diploid daughter cells are produced |
|
|
Term
|
Definition
Duplicated chromosomes start to condense
-initiation of spindle formation
-condensation of duplicated chromosomes
-Fragmentatin of ER and Golgi
-Nucleolous disappears
-Nuclear membrane breaks down
-Spindle microtubules invade the nuclear space |
|
|
Term
|
Definition
| -Chromosomal microtubules attach to KINETOCHORES which are on the outer surface of centromeres; chromosomes move towards the equator of the spindle |
|
|
Term
|
Definition
Duplicated chromosomes migrate to the equatorial plane of the cell and the nuclear membrane breaks down
-the chromosomes are aligned midway between the spindle poles
-this equatorial plane is called the metaphase plate |
|
|
Term
|
Definition
| Sister chromatids of each duplicated chromosome move to opposite poles of the cell |
|
|
Term
|
Definition
Chromosomes decondense and new nuclear membranes form
-Golgi and ER reform
-Daughter cells form by CYTOKINESIS |
|
|
Term
|
Definition
| Membrane forms between daughter cells (cytokinesis) |
|
|
Term
| n number of chromosomes = |
|
Definition
|
|
Term
| 2n number of chromosomes = |
|
Definition
|
|
Term
| MEIOSIS involes ____ cell divisions |
|
Definition
|
|
Term
| pairing of homologous chromosomes is called ________ and is often facilitated by formation of a __________ _______ |
|
Definition
| Synapsis ; synaptonemal complex (a scaffold where chromatids attach to) |
|
|
Term
| Meiosis I: Prophase I phases: |
|
Definition
| Leptonema (chromosomes with 2 sister chromatids begin to condense), zygonema (homolougous c-somes begin to pair), pachynema (homologs are fully paired), diplonema (c-somes seperate except at chiasmata) |
|
|
Term
| When two homologous c-somes pair up (so there are 4 chromatids, 2 from Mom, 2 from Dad) they are called a ________ or a __________ |
|
Definition
|
|
Term
| The prophase I : Diplonema stage may last... |
|
Definition
| for the entire reproducting life of the individual (human women = more than 40 years) |
|
|
Term
|
Definition
| The cell division in Meiosis I |
|
|
Term
|
Definition
paired chromosomes align on the equatorial plane in the cell
NOTE : Anaphase / telophase are just like mitosis for the rest, so Im not going to define them |
|
|
Term
|
Definition
| two haploid daughter cells that are genetically different |
|
|
Term
| This resembles a mitotic division, but the products are haploid |
|
Definition
|
|
Term
| What changes between Prophase I and II? |
|
Definition
| The kinetochore position. Outside for I and pulling two chromatids away, while in II, two chromatids are being pulled away from each other. |
|
|
Term
|
Definition
|
|
Term
| Meiosis I begins in the ____ _______ but arrests at Prophase I |
|
Definition
|
|
Term
| For ovulation, and egg matures to metaphase II and is released into the _____ ________ |
|
Definition
|
|
Term
| At the time of fetilization, the oocyte is still _____ and meiosis II is completed **AFTER** fetilization |
|
Definition
|
|
Term
| Budding is characteristic of _____ _________ |
|
Definition
|
|
Term
| A true alternation of generations : |
|
Definition
| Sporophyte to gametophyte (google for a diagram maybe?) |
|
|
Term
| In floweing plants, the _________ is the conspicuous part of the life cycle |
|
Definition
|
|
Term
| The ___________ is much reduced and consists of just a few haploid cells in the anther and ovary of the flower |
|
Definition
|
|
Term
| Why did Mendel's peas breed true? |
|
Definition
| They were highly inbred because the flower structure promoted self-fertilization |
|
|
Term
| When only one trait is examined in a cross (with only 2 possible variations) |
|
Definition
|
|
Term
| Mende's heritable factor = |
|
Definition
|
|
Term
| Each trait is controlled by a heritable factor that came in one of two forms: |
|
Definition
|
|
Term
| Dominant and recessive forms called: |
|
Definition
|
|
Term
| When both alleles are identical |
|
Definition
|
|
Term
| When the alleles are different |
|
Definition
|
|
Term
| From the P (parent generation) the next gen. is called what? |
|
Definition
|
|
Term
| What about the grand-offspring? |
|
Definition
|
|
Term
| QUESTION: During mitosis, will an allele on one sister chromatid always match the allele on the other sister chromatid? |
|
Definition
| YES! Because sister chromatids are the product of DNA replication |
|
|
Term
| Neither allele is typically changed by coexisting with the other in a heterozygote: |
|
Definition
Mendel's Principle of Segregation
*Two different alleles segregate from each other during the formation of gametes |
|
|
Term
|
Definition
When two traits are examined for the same cross
ie. yellow,round and green,wrinkled seeds |
|
|
Term
QUESTION: which would you normally not find in the nucleus?
-Cytochrome C
-Lamin
-Actin
-Histone
-snRNA |
|
Definition
|
|
Term
| Mendel's Principle of Independent Assortment |
|
Definition
The alleles of different genes assort/segregate independently of each other
--> Any combination is RANDOM and all are EQUALLY LIKELY TO OCCUR |
|
|
Term
|
Definition
| a fixed position on a chromosome |
|
|
Term
|
Definition
| It is the smaller arm on a chromosome/chromatid |
|
|
Term
|
Definition
| The larger end on a chromosome/chromatid |
|
|
Term
| The General Rule (for predicting genotypes and stuff) |
|
Definition
For n different genes assorting independently, there are:
(2x2x2...)n = 2^n possible haploid genotypes |
|
|
Term
| The further apart two genes are on a chromosome, the MORE/LESS likely they are to assort independently |
|
Definition
|
|
Term
| Review the Forked Line Method for predicting the outcome of a cross involving ________ independently assorted genes |
|
Definition
|
|
Term
| The rules of probability --> The Multiplicative Rule |
|
Definition
| If the events A and B are independent, the probability that they occur together is the product of their individual probabilities of occurrence (P(A) x P(B)) |
|
|
Term
| The rules of probability --> The Additive Rule |
|
Definition
If the events A and B are independent, the probability that at least one of them occurs is the sum of their individual probabilities of occurrence minus the probability of their joint occurrence.
ACCOUNTS FOR ANY OVERLAP! :)
P(A) + P(B) - [P(A) x P(B)] |
|
|
Term
| In a TEST CROSS, the individual of unknown genotype must be crossed with a __________ __________ individual |
|
Definition
|
|
Term
| In a pedigree, a trait is likely showing a dominant mode of inheritance if... |
|
Definition
-Every affected individual has at least ONE affected parent
-The trait is manifested in at least one individual in every generation ONCE THE TRAIT APPEARS |
|
|
Term
| A trait is likely showing a recessive mode of inheritance if... (3) |
|
Definition
-The trait suddenly appears in a pedigree
-It skips a generation
-In the absence of evidence to the contrary, assume that unrelated individuals marrying into the family do not carry the recessive allele |
|
|
Term
| Mathmatically, for a total number of n progeny, we can calculate the binomial probability that exactly x progeny will fall into one class, and y into the other class with this formula: |
|
Definition
|
|
Term
| A transcribed region of DNA |
|
Definition
|
|
Term
5 classes of RNAs
(All in nucleus for synthesis) |
|
Definition
1. snRNA
2. rRNA
3. tRNA
4. mRNA
5. Pre-miRNA
-recently discovered
-every animal has these micro-RNAs
-very important in the regulation of gene expression |
|
|
Term
| RNA uses _________ instead of thymine |
|
Definition
| pyrimidine uracil (U) instead of T |
|
|
Term
| What is the CENTRAL DOGMA of molecular biology? |
|
Definition
| That the transfer of information from DNA to protein is a 2 step process in all organism: Transcription and Translation |
|
|
Term
| the mRNA template strand is read from: |
|
Definition
|
|
Term
| What is locally unwound during transcription? |
|
Definition
|
|
Term
| A piece of DNA that promotes transcription |
|
Definition
|
|
Term
| When six A's are transcripted, what does this mean? |
|
Definition
| It's a transcription terminator sequence, and once it is read there is a rapid folding of the newly transcripted RNA into a "hairpin" |
|
|
Term
| In prokaryotes, genes are compact and several can be encoded on... |
|
Definition
|
|
Term
| After the primary transcript is processed, where is it exported for translation? |
|
Definition
|
|
Term
| Unlike prokaryotic RNA polymerases, eukaryotic pols cannot initiate transcription on their own, they require a _________ ____________ |
|
Definition
Transcription Factor
-the bind to the promoter to help assemble or stabilize the transcription machinery |
|
|
Term
|
Definition
-Sequences in eukaryotic promoters also position the RNA polymerase for accurate initiation of transcription
-This box is a highly conserved feature of many protein-coding genes |
|
|
Term
| Once the transcript proteins reaches a ____-_____ sequence, it means to stop transcription. |
|
Definition
GU-rich
**Close to 3' end of RNA molecule
Then cleavage occurs by endonuclease and a Poly(A) tail is tacked onto the end -AAAAAA (A) on the 3' end. |
|
|
Term
These are noncoding sequences located between coding sequences. They are removed from the pre-mRNA and are not present in the mature mRNA.
They are variable in size and may be very large. |
|
Definition
| Introns (or Intervening sequences) |
|
|
Term
| These are composed of the sequences that remain in the mature mRNA after splicing |
|
Definition
| Exons (both coding and noncoding sequences) |
|
|
Term
| These are an intermediate between DNA and protein |
|
Definition
|
|
Term
| In prokaryotes, an RNA sequence positions the ribosome to begin ___________ at the beginning of a _________ __________ |
|
Definition
| Translation; coding sequence (or open reading frame) |
|
|
Term
| Proteins are assembled on the __________ according to the mRNA sequence (the genetic code) |
|
Definition
|
|
Term
| Codon = mRNA, while anti-codon = ________ |
|
Definition
tRNA
*REVIEW DIFFERENCE BETWEEN CODON/ANTI-CODON!! |
|
|
Term
| There are no __________ between codons, they are _________ |
|
Definition
|
|
Term
| The genetic code is _____-__________ |
|
Definition
non-overlapping
**each nucleotide is part of one codon |
|
|
Term
| The genetic code is ______, __________ and _________ |
|
Definition
degenerate (most amino acids are specified by more than one codon)
(nearly) Universal (with minor exceptions, each triplet/codon has the same meaning in all organisms)
ordered (amino acids with similar properties are specified by related codons) |
|
|
Term
|
Definition
randomly and spontaneously
-it is a result of an error during DNA synthesis |
|
|
Term
| The nitrogenous bases of DNA exist in 2 isoforms, called ___________ |
|
Definition
tautomers.
There are common and rare ones
-The RARE isoforms have altered base pairing properties |
|
|
Term
| What are the 3 "hot spots" for spontaneous mutations during DNA replication: |
|
Definition
-Simple repeats
-Symmetrical repeats
-Palindromes |
|
|
Term
| Mutations can be induced by (2): |
|
Definition
| chemical mutagens or radiation |
|
|
Term
| Chemical mutagens can be divided into 2 groups: |
|
Definition
1) those that are mutagenic only to replicating DNA
(ie. base analogues, acridine dyes)
2) those that are mutagenic to both replicating and non-replicating DNA
(ie. alkylating agents like ethyl methan sulphonate EMS) |
|
|
Term
| Absorbtion of ___ ______ by pyrimidines results in their dimerization |
|
Definition
|
|
Term
| A few effects of single base mutations (3) |
|
Definition
1. silent (no change)
2. nonsense (a stop codon)
3. missense (conservative(similar to original, probably no effect) vs non-conserved) |
|
|
Term
| Acridines intercalate between adjacent base pairs and ______ the ______ ________ |
|
Definition
|
|
Term
| Mutations can also be induced by the _____ itself |
|
Definition
DNA
-transposable elements |
|
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Term
| At least 15 human inherited disorders result from... |
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Definition
expanding triplet/trinucleotide repeats
ie. each new generation the mutagenic codon repeats another set amount (just keeps building up)
-increased severity and/or earlier onset
This phenomenon is ANTICIPATION |
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Term
| Mutations that affect the coding region (2) : |
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Definition
1. Changes protein to a non-functional form
-changes to protein folding
-prevent proper localization of the protein
- targeted for degradation
- compromised activity
2. Post-translational modification
-prevent proper localization of the protein
- "unactivatable" |
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Term
| Mutations that affect non-coding regions (2): |
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Definition
1. Prevent or reduce transcription
2. Prevent or reduce translation
-mRNA is unstable
- ribosomes can't bind
- mutation of the START codon |
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Term
| Myotonic dystrophy type I |
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Definition
| CTG expansion in the untranslated region (UTR) of an mRNA transcribed from chromosome 19 encoding an enzyme (kinase) |
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Term
| Myotonic dystrophy type II |
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Definition
| CTG expansion in an intron of a gene on chromosome 3 encoding a zinc finger transcription factor |
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Term
| IN BOTH CASE ABOVE, the mRNA may..... |
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Definition
| become too large for export into the cytoplasm |
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Term
| T or F, genes usually have more than 2 alleles |
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Definition
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Term
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Definition
| the most common allele (not necessarily the dominant one) |
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Term
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Definition
Any allele found at appreciable frequencies
All other alleles = mutants (when less than 1% of population has it) |
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Term
| T or F, recessive mutations almost always involve a loss of gene function. |
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Definition
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Term
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Definition
| complete loss of function |
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Term
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Definition
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Term
| dominant mutations can result in a loss of function or a gain |
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Definition
| When it is loss, it meands that for those genes, one functional copy is NOT enough (HAPLOINSUFFICIENCY) |
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Term
| A loss of function mutation that interferes with the normal function of the wildtype allele |
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Definition
| Dominant Negative Mutation |
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Term
| enhances the normal function of the gene |
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Definition
| Gain of function mutation |
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Term
-The phenotype of the heterozygote is midway between the phenotypes of the two
-One allele is partially, or incompletely, dominant over the other |
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Definition
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Term
-The heterozygote expresses the phenotypes of both homozygotes
-Neither allele is dominant |
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Definition
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Term
| Multiple alleles of a single gene with a ________ ___________ |
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Definition
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Term
| An ______ _______ describes the dominance hierarchy of multiple alleles |
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Definition
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Term
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Definition
A dominant visible allele that is also a recessive lethal
(involved in at least 2 different developmental processes) |
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Term
| What 2 factors are phenotypes influenced by? |
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Definition
| Genetic and Environmental (internal and external) |
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Term
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Definition
| a gene that affects many phenotypes |
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Term
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Definition
Individuals do not express a trait even though they have the appropriate genotype
ie. polydactyly |
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Term
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Definition
| A trait is not manifested uniformly among individuals that show it |
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Term
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Definition
An allele of one gene overrides the effect of other genes on the phenotype
I.e. white and red eye alleles both appear in a mutation.. white will override the red in fruit flies |
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