Hybrid breakdown – when offspring of hybrids are infertile
Cell anemia – glutamic acid is replaced by valine in the 6 Beta position of autosomal recessive lethal gene = 0.4 frequency of carrier in population of 200 individual is p2 + 2pq +q2 = 1 die due to lethal So 2pq = 2 x 0.6 x 0.4 = 0.48 and N = 200, So freq. of carrier = 0.48 x 200 = 96
Hot spots – sites which are more mutable then other sites (Benzer) e.g. smethyl Cytosine residues
More closely related sexual partners less are variations in their off springs.
Classical / forward genetics – study of phenotype, analysis & isolation of concerned genes & study of DNA sequence comprising genes.
Reverse genetics – if we start DNA Seq. study from phenotypic effect of which we do not know & then introduce in some animal to study its phenotypic effect.
Blending of inheritable chromosome is the intermingling of heredity material of both offspring’s.
Mendel’s success – pea easy to cultivate, naturally self-pollinated, artificially cross-pollinate.
Mendel’s success – sharply defined inherited differences in difference varieties, only one variable at a time
In rr seeds in small DNA Fragment interferes with SBE – 1 so starch in not formed and it accumulates as sugar – causer high osmotic pressure lead to shrinkage & wrinkling.
Dihydric cross - inheritance of seed color is independent of seed shape.
Homozygous - condition in which only one allele is present of a pair
Mendel used element for factor -> gene
Genotype exhibiting difference phenotype under difference environmental conditions – Individual norm of reaction
Same environment & genotype but phenotype differ due to difference in internal environment = Developmental noise
2 different genotype produce same phenotype due to different environment & have difference genotype = phenocopies of each other
If a dwarf plant introduced tall by gibberellin acid then too it would behave as dwarf genetically.
In haploid organism – chromosome are governed only by one allele then law of dominance & Segregation do not apply.
Locus = position of allele on chromosome
Back cross Tt X any parent
Test cross Tt X recessive (tt) Phenotype = 1 : 1 : 1 : 1
Hugo – de Vries (Dutch) cosrrens(Germany) Tschermark (Austrian) -> Mendel’s work as principles & coined term factor
Bateson – 1st announced Mendel’s work in England (poultry, rabbit, sweet pea)
Bateson coined homozygous, heterozygous, allomorphs – “ Mendel’s principle of heredity”
Nageli advised Mendel to work on Hieracium (But he failed) seeds produced without pollination
Mendel = 1st genetic surgeon
No Of gene pair
Genetic markers => Alleles.
Albinism = autosomal recessive mutation. If 1st child of a normal pair in albino what is the is the probability of 2nd child for albino = 25% (due to recessive chromosome so only homozygous condition will show albinism)
Tt x Tt -> tt(25%) = answer
1st child is independent of the 2nd child
What would be proportion of Tt Yy Ss Dd Ee from a cross
Tt Yy Ss Dd Ee X Tt Yy Ss Cc Dd Ee
Answer: of progeny will be
TT, yy, Ss, Cc, dd, Ee.
x x x x x = answer