Inheritance/heredity:-
Character which transfer one generation to another generation
Variation :-
Difference in traits of individual ,each other and from parents
Mendel (Father of genetics) experiment:-
# He performed experiment on pea plant (pisum sativum)
# conducted artificial pollination
Mendel observation:-
# F1 generation always resemblance to one of parent
# F2 generation resemblance both of parent
Mendel law's :-
1.) Law of dominance (first law):-
When two alternative form of a trait or character are present in an organism, only one factor express itself in F1 progeny, while the other remain maskes
2.) Law of segregration (second law):-
The factor or allele of a pair segregate from each other during gamete formation, such that gamete receives only one of two factor,do not show any blending
3.) Law of independent assortment :-
The two factor of each character assort or separate out independent of the factor of other character at the time of gamete formation and get randomly rearranged in the offspring produce producing both parental and new combination of character
Incomplete Dominance:-
Phenomenon in which F1 hybrid character intermediate of the parental gene
Co-dominance :-
The allele which are able to express themselves independently when present together
Test cross:-
Organism with unknown dominant genotype is crossed with recessive parent
Pleiotrophy:-
When single gene exhibit multiple phenotypic expression
Polygenic inheritance :-
Inheritance control by three or more gene
Chromosomal theory of inheritance:-
Proposed by Walter Sutton & Theodore Boveri
# all heredity character must carried by gamete
# they are all carried in nucleus
# chromosome found in pair
# Homologous chromosome get seperated to pass into different cell during synapse
Linkage And Recombinance :-
# T.H Morgan, observed that when two gene in dihybrid cross are located on the same chromosome
# Some gene are tightly linked or associated and show low recombination
# gene loosely linked show low recombination
Sex Determination mechanism:-
Finalisation of sex at the time of zygote formation
Type:-
# XX-XY type:-
In mammals including human
# XX-XO type:-
In grasshopper
# ZZ-ZW type:-
birds, fishes
# ZO-ZZ type:-
In cockroaches
Mutation :-
Sudden inheritable change in genetic material of an organism.
Type
# Gene mutation:-
1) point mutation
2) frame shift mutation
# chromosomal mutation :-
1) structural variation/ chromosomal abbreviation
2) Numerical variation
2.1 Aneuploidy
2.1.1 = Trisomy
2.1.2 = Monosomy
2.2 polyploidy
Mutagen:-
Agent of mutation
Pedigree Analysis :-
Study of inheritance of genetic traits in several generation of a human family in form of family tree diagram
Mendelian Disorder:-
Disease caused due to alteration or mutation in single gene
# Haemophilia:-
Sex linked recessive disorder
# Sickle cell anaemia:-
Autosome linked recessive trait
# phenylketonuria:-
Inborn error of metabolism, autosomal recessive trait
# Thalassemia:-
Autosome linked recessive disease
# colour blindness:-
Sex linked recessive disorder
Chromosomal disorder :-
# Caused due to excess, absence or abnormal arrangement of one or more chromosome
# chromatids fail segregate during cell division
1) Down syndrome :-
Additional copy of chromosome number 21 or trisomy of chromosome 21
2) Klinefelter's syndrome :-
Presence of an additional copy of X chromosome resulting in karyotype 45+XXY
3) Turner's syndrome :-
Absence of one of X chromosome, resulting in karyotype 45+XO
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