Notatki Danniego part 3 Flashcards
Mendel crossed green wrinkled with Yellow Round peas - he noticed that …
the gene for the colour did not affect the gene for shape -> independent assortment
Agouti mice -
black hair crossed with small yellow streak (agouti hair)
Aa AA - agouti aa - black
Bb BB - black bb - brown
P: AABB x aabb
f1 - all AaBb - agouti
f1^2 resulted in:
f2: 9 Agouti (A_ B_) 3 Cinamon (A_ bb) 3 Black (aa B_) 1 brown (aa bb)
Cinamon mice need changes at 2 genes so they interact -> Epistasis
Albino mice -
C locus - codes for pigment
cc- albinos
BBCC x bbcc
f1^2
f2:
9 Black (B_C_) 3 Brown (bb C_) 3 Albino (B_ cc) 1 Albino (bb cc)
9:3:4 ratio as last two classes have the same phenotype and the epistatic albino alleles at the C locus which masks the phenotype at the B locus
α, β - globin is a part of gene family
- > group of genes with a conected function that split and diverge from a common ancestor
- > duplicated themselves and dimerged
α- globin - much throughout the life
β- globin - much after birth, before birth there’s none
γ - globin found only in the foetus
- > higher affinity for oxygen
- > called Hbf
γ - globin - much before birth, after there’s none
1-2% left in adults
HbfH (gene) - originate from Saudi/Senegal
- You keep γ - globin in adult life
- Counteracts sickle cell anaemia
Chemicals can be given to adults to switch on foetal haemoglobin gene
- > reduced effects of sickle cell anaemia
- > gene interaction
Protective Mechanisms thalassemia - protects against …
malaria
Protective Mechanisms thalassemia: describe
- > inherited autosomal recessive disease
- > abnormal formation of haemoglobin
- > deletion of part of the α or β - globin
Protective Mechanisms thalassemia: what happens because of this deletion?
deletion reduces amount of haemoglobin in each red blood cell
- > that means sickle cell anaemia cannot change the shape as much
- > 2 bads make a good
- > a gene interaction
complenentation - purple & white foxgloves
P1 white line 1 x white line 2
P1 w1w1 W2W2 x W1W1 w2w2
f1 all W1w1 W2w2 (purple)
f2: 9 Purple (W1_ W2_) 3 White (W1_ w2w2) 3 White (w1w1 W2_) 1 white (w1w1 w2w2)
9:7
Blue eyed white cats are deaf due to …
melanin
2 types of deafness + generally about deafness
- sensory
- conductory
At least 100 different loci that can cause deafness
-> 1/4 dominant, 3/4 recessive
Centromere -
Attaches a chromosome to the spindle when cell divides
Telomeres -
A region of repetitive nucleotide sequences at each end of a chromatid
-> protects the ends from deterioration or fustion with a neighbouring chromosome
G -banding
old method of staining chromosomes
- attaches to wound up (heterochromatin) sectors of the chromosome (inactive)
New method of staining chromosomes -
chromosome painting
Chromosome rearrangements:
1. Deletion
1_2_3_4 -> 1___4
Chromosome rearrangements:
2. Duplication
12 3_4 1_2_4
\ / ->
1_2_3/ _4 1_2_3_3_4
2 homologous chromosomes line up next to each other
- > slippage
- > misaligment 1234 lines up
Chromosome rearrangements:
3. Inversion
1_x_2_3_x_4 -> 1_3_2_4
Chromosome rearrangements:
4. Reciprocal translation
12 x 3_4 1_2_8_9_10
->
5_6_7 x_8_9_10 5_6_7_3_4
Break in both chromosomes and joining in wrong order
Deletion:
A section of chromosome is removed
-> Notch’ wing in Drosophila flies
gene family -
groups of genes that are similar and descend from a common ancestor
globin family -
α chain on chromosome 16
β chain on chromosome 11
myoglobin on chromosome 22
Ψ - pseudogene
no longer used gene
odorant gene family -
388 working genes
400+ non-working genes
