Bio Test Mutations
-
Upload
shoshanna-natanya -
Category
Documents
-
view
218 -
download
0
Transcript of Bio Test Mutations
-
8/7/2019 Bio Test Mutations
1/23
Bio Test
Mutations
-
8/7/2019 Bio Test Mutations
2/23
Types of Mutations
Changes in genetic structure
Phenotype- physical appearance
Genotype- genetic combination
Types: Pointsimplest type of mutation, one BP doesnt line up
Frameshift nonsense- stop codon in the coden halts protein synthesis Silent substitutionthe amino acid is still the same
Missense substitutionchanges the amino acid, changes the phenotype
Deletion/Insertion BP are removed or inserted
Wild type forward mutation- change from wild type
-Backward mutation- back towards wild type
Frameshift will effect phenotype
Block deletion- delete multiple base pairs Translocation mutations part of a chromosome physically moves
Duplication mutationmutiple copies of the same structure (selective environmentalpressures)
(DNA polymerase)
-
8/7/2019 Bio Test Mutations
3/23
-
8/7/2019 Bio Test Mutations
4/23
Cancer
Failure of apoptosis in cells
Failure of contact inhibition signals
Caused by mutations
Metastasis- spreading of cancer cell Oncogene- causes cancerous mutations
Proto-oncogene- gene that is susceptible tomutation that will give rise to uncontrolled
growth (cancer) Testing DNA must be sequenced and compared
to know if presence of proto-oncogene
-
8/7/2019 Bio Test Mutations
5/23
Virus
RNA tumor virusretroviral
DNA tumor virus>>>>**?
I. Altered Gene1. Incorporation of retroviral Oncogene
2. Mutation of normal proto-oncogene to create an oncogeneII. Altered gene expression in which a gene is transcribed at the wrong
time, or too high a rate
1. Insertion next to proto-oncogene of retroviral DNA containing anactive control region
2. Translocation of a proto-oncogene to a position next to an activecontrol region3. Translocation of an active control region to a position next toproto-oncogene
-
8/7/2019 Bio Test Mutations
6/23
Gene Transfer
Movement of gene from one bacterium to
another can happen in various ways
Mechanical Methods: Transduction Non-mechanical Methods: Transformation,
conjugation
-
8/7/2019 Bio Test Mutations
7/23
Transduction-
transfers DNA between bacteria
1. Phage injects its DNA (bacteriophage=
complex bacteria)
2. Phage enzymes degrade host DNA3. Cell synthesizes new phages that incorporate
phage DNA (and mistakenly some host DNA)
4. Transducing phage interjects donor DNA5. Donor DNA is incorporated into recipients
chromosomes by recombination
-
8/7/2019 Bio Test Mutations
8/23
Transformation
Most bacteria have the ability to absorb DNA
Can allow a new biochemical organization
Griffiths experiment with the mice
-
8/7/2019 Bio Test Mutations
9/23
Conjugation
F+ plasmid=extranuclear DNA
Conjugation pilus= connection between bacterium cells
Graham negative organism- one type of cell wall in
bacteria1. Donor cell attaches to recipient cell with its pilus. Thepilus draws the cells together
2. The cells contact each other
3. The plasmid replicates one of its strands and transfers
the daughter strand to recipient through pilus4. The recipient simultaneously synthesizes a
complementary strand to become an F+ cell
-
8/7/2019 Bio Test Mutations
10/23
Plasmid Function
Fertility
Resistance Factor- resist antibiotics
Bacterium Factor- resist chemical treatment
Virulence Factor- increases pathoginicity Cryptic- high frequency Hfr Conjugation, plasmid
splices itself into the host genome, transfers parts ofgenome between cells
Transposable Element (aka transposon or jumping
gene)- small pieces of DNA jump from one chromsometo another- effects phenotypebarabraMaclintock-discovered this with corn
-
8/7/2019 Bio Test Mutations
11/23
Chromosome
Centromere-divides chromosome into arms located in thecenter
Metra-centromere- uneven divide Q arms above centromere
Teleocentric- at the end of a chromosome P arms belowcentromere
(chromsone 21,22 have short/non-existent q arms)
Kinetochore- spindle fiber attachment
Acrocentric- v. off center
Telomere- responsible for aging?
Dark band-hetero-chromatin-has high cone adenine + thymine
Light band- euchromatin- high cone of guanine + cytosine
Topological structure- banding patterns, arms length, centromerelocation all help define karyoypes- physical representation of thechromsomes to determine any problems
-
8/7/2019 Bio Test Mutations
12/23
Nuclear Division
M- phase mitotic (after build up of M cyclin that builds up in G2 phase)
Entering M phase: 1. the centrioles duplicate, (centrioles are made of tublin- microtubulies ( + ) arrangement)
Mitotic organizing center (MOC) organizes spindle fibers
Prophase:
2. Centrioles move to poles of cell
3. Form short spindle fibers called Aster Rays
4. Forms long spindle fibers5. As fibers move to poles of cell, nuclear envelope and nucleolus disappear
Metaphase:
6. Spindle fibers attach the Kinetochore to outside of centrioles
7. Fibers line up in middle of cell (equator)
8. Centromere duplicates so sister chromatids separate
Anaphase:
9. Spindle fibers start to contract- pulling the chromosome to the centrioles (the poles)
10. Fibers push the cytoplasm in different directions
11. Aster rays pull and push cytoplasm
12. Furrowing takes place cytokinesis
Telophase:
13. As chromsomes approach centrioles- chromsomes relax, spindle fibers diappear
-
8/7/2019 Bio Test Mutations
13/23
Cell Plate Formation
Directed by Golgi Apparatus
Phragmoplast (microtubules)- directs the placement of the vesicles
As the materials in the vesicles are released, the vesicles fuse into asolid plate of cellulose to form the cell walls
Right after cell walls are separated- cells must go through anothergrowth period
Acid Growth Hypothesis- cell grows to full size after separating
Cytoplasm of cell pumps H+ in between cell membrane and cell wall
1. Excess of H+ loosens cellulose fibers
2. space in between membrane and wall is hypertonic (water goesin between space and stretches the cell- neutralizes the H+ acid
-
8/7/2019 Bio Test Mutations
14/23
Meiosis
Process of gamete production
Nuclear division- reduction division
the total chromosomes in offspring cells
2 nuclear divisions= 4 cells
Om metaphase I instead of line up there is a formation of tetrad
Meiosis is only in gamete cells
(v. similar to mitosis)Only differences:
Homologous chromosomes form tetrad- called chiasmata
When tetrad reaches the equator spindle fiber attaches to the the kineticore of the outside of thetetrad
Separation of the pairs of chromosomes- no centromere duplication
Cells from 2 offspring cells with attached sister chromotids
Interkinesis phase- between divisions
-------
2nd set of divisions-identical to mitosis!
Result? Offspring cells (4) each have the genetic material of the parental cells
(haploid cells)
-
8/7/2019 Bio Test Mutations
15/23
Crossover arms of homo-chromosomes-
exchange tips- create genetic diversity
Synapse-location of crossing over Homologous pairs are connected in middle by
axial protein to form tetra
-
8/7/2019 Bio Test Mutations
16/23
Gamete Production (Animals)
Spermatogenesis (males)- at end of meiotic
division end with 4 fertilizing cells (interstitial
cells)
- outcomes are identical in plants and animals
Primary spermatocyte- end up with 4
spermatozoa
-
8/7/2019 Bio Test Mutations
17/23
Oogenesis
MetoticDivison I
(If fertalized)
MetoticDivison IIOotid + 3 polar bodies
Ovum-------------------
-
8/7/2019 Bio Test Mutations
18/23
Haploid- 1 set of chromosomes
Diploid- 2 sets
Karyogamy- union of nuclei when fertlized=zygote
Thallus- disintegrates after sporyte is
produced (must swim to females)
-
8/7/2019 Bio Test Mutations
19/23
Plants
In the 2 major plant groups: conifers & flowering plants
The process of reproduction involves 2 special types ofgamete producing cells Microspore mother cells- divides 2x by meiosis-forms 4 pollen
grams Megaspore mother cells- divides 2x by meiosis to form 4
embryos but 3 dissolve, the lone nucleus then divides by mitosis3x to five a total of 8 nuclei migrate to form the synergids,polar nucli, and anti-podals
Endosperm- food for growing embryo (lipids)- glycolyticpathway using glyoxisomes (made from polar bodies +sperm)
Gymnosperms-growth of tube takes 1 yr so not fertilized till2nd year
-
8/7/2019 Bio Test Mutations
20/23
Chromosome Mutations
Involve nondisjunction- failure of homologouschromatids to separate in meiosis
1. 18th chromosome: Edwards syndrome- Full term
infant doesnt live past 1st
month.organ problems, elongated head, often bornw/only brainstem
2. Downs syndrome: called Mongolism. Extra
21
st
chromsome3. Crydocnat- baby sounds like meowing cat. On13th mutation trisome. Hole in heart, organfailure, live
-
8/7/2019 Bio Test Mutations
21/23
Reproductive Nondisjunctions
XXY-Klinfelters syndrome: doesnt go throughpuberty- infertile
X-Turners syndrome: 1 of 8000 females born,
short, webbed neck, widely separated nipples,shield shaped chest, learning disorders, sterile
XYY- Jacobs syndrome: 1 in 400 males, tall,aggressive, learning disabilities, tend to be
incarcerated
XXX- metafemale: possibility of learningdisabilities
-
8/7/2019 Bio Test Mutations
22/23
Multiple chromosomes
Allopolyploidy- multiple chromosomes due tobreeding
Winter wheat- triploid, grass carp (CAN
reproduce), bananas
Autopolyploidy- m.c. due to to mutation
Direct result of nondisjunction in gametes givingorganisms a natural selection and vantangle-adaption advantage (rare) has to be even-ploid toreproduce
-
8/7/2019 Bio Test Mutations
23/23
Genetics
P-generationparental
Pure breeding- homozygous recessive ordominate- aa or AA
heterozygous- Aa or aA
F1 generation- first filial
F2- Second filial
Law of segregating traits (mendel) allelesseparate from each other in division go toseparate gametes Ponnett squares