Genetics Flashcards
Term genetics was coined by
Bateson.
Father of genetics is
Gregor John Mendel
Living organism studied in classical genetics is/was
Pea plant (pisum sativum) = garden pea Mendel also tried to work on Hawk-weed (Hieraceum).
Which technique is used in classical genetics
Hybridization
Father of modern genetics is
Bateson
Father of experimental genetics is
T.H.Morgan
Aka flyman of genetics (bcz he worked on fruitfly)
Living organism studied in modern genetics was/is
Fruitfly ( Drosophila melanogoster) and Pink bread mould (Neurospora crassa) aka drosophila of plant kingdom.
Father of human genetics is
Sir Archibald Garald.
Worked on a genetic disorder c/d Alkaptoneuria.
Drosophila of plant kingdom is
Pink bread mould (Neurospora crassa).
What’s Eugenics?
Improvement in human race by application of genetics.
Whats euphenics?
Application of genetics for treatment of genetic disorders.
Whats euthenics?
Improvement in human race by providing proper environment.
Diagynic inheritance?
Transmission of charac. from male to male “via female”.
Dia=via ; gynae=female
Diandric inheritance?
Transmission of charac. from female to female “via male”.
Dia=via ; andric =male
Holoandric inheritance?
Transmission of charac from male to male to male and so on.
Holo=complete ; andric =male
Hologynic inheritance?
Transmission of charac from female to female to female and so on.
Holo = complete ; gyna =female
Name the modes of transmission (found in majority).
Diagynic
Diandric
Hologynic
Holoandric
Physical basis of heridity is
Gene
Chemical basis of heredity is
DNA 🧬
_________ is the basis of heredity. [ncert]
Inheritance
Who first time applied statistical analysis & mathematical logic to problems in biology?
Mendel.
During his investigations into inheritance patterns…
Pre-formation theory was given by
Swammerdam
Found small humans inside head of sperms and c/d them homunculus.
Theory of pangenesis was given by
Darwin.
Theory of continuity of germplasm was given by
Weisman.
Said: somatoplasm isn’t inherited (mortal) whereas germ plasm is inherited (immortal).
Sutton & boveri gave ______ theory regarding heredity.
Chromosomal theory of inheritance.
Discontinuous variations (org. is deviated from normal) occur due to
Exposure to some mutagens (x-rays, gamma rays, uv rays, silver nitrate, benzopyrene etc)
Continuous variation (org. isn’t deviated from normal) occur due to
Crossing over.
D.O.B of Mendel
20th July, 1822 in Hezendorf, Austria. “(Austrian monk)”
Mendel cultivated plants for 7 yrs from ____to ___.
1856-63 : he cultivated 25,000 pea plants.
Mendel published his work/paper in
1865.
Death of Mendel
6th jan,1884 due to chronic nephritis (kidney failure).
Main reason for Mendel’s success was
Luck
Other reasons for Mendels success are
Luck
Hardwork
Scientific attitude
Mathematical background
Who re-discovered Mendels work and when?
In 1900, 3 scientists- Hugo de vries, Correns, Tschemark re-discovered Mendel’s work.
1900 => 16 yrs after his death or 34yrs after his publication
Name the dutch scientist who re-discovered Mendel’s work?
Hugo de vries from Holland ( dutch )
Correns was from Germany and Tschemark was from Austria.
T/F
True.
Who re-published Mendel’s work and in which journal?
Hugo de vries re-published Mendel’s work in ‘Flora’ in 1901.
Term gene was coined by
Johnssen.
Gene aka medelian factor aka factor.
Term allele was coined by
Bateson
Dominant allele is the one that expresses in
Heterozygous condition only.
Number of traits selected by Mendel were??
14 i.e 2x7 characters
Complete the table:(in order that chr.no. follows 4414571 ) Characters studied by Mendel | Dominant | Recessive | Chr.no. 1) 2) 3) 4) 5) 6) 7)
Hgt. Of plant _ Tall _ Dwarf _4 Flower position _Axial _Terminal _4 Flower colour _Violet _white _1 Pod shape _inflated _constricted _4 Pod colour _green _yellow _5 Seed shape _round _wrinkled _7 Seed colour _yellow _green _1
Note:to denote these, consider 1st letter of each dominant charac.
Egs., Violet => V => VV & vv
Characters studied by Mendel are present on __ chromosomes with no.s __,__,__,__.
4 chromosomes
I.e 4,1,5,7
No. Of gametes formed =
2^n
Where n is the no. Of heterozygosities.
Eg., AaBbCCeeDd
Here n=3 as Aa , Bb & Dd are heterozygous where as CC & ee are homozygous.
=> no. Of gametes = 2^3=8
**on how to make these gametes, refer notebook.
Phenotypic ratio for mono hybrid cross is
3:1
I.e tall:dwarf = 3:1 or round:wrinkled or dominant:recessive type
Genotypic ratio for mono hybrid cross is
1:2:1
TT : Tt: tt type
Phenotypic ratio for di hybrid cross is
9:3:3:1
T,R : T,r : t,R : t,r type
Genotypic ratio for dihybrid cross is
1:2:1:2:4:2:1:2:1
To know how this looks in punett square refer notebook
In general, phenotypic & genotypic ratio is given by
Phenotypic ratio = (3:1)^x where x is cross no.
Genotypic ratio = (1:2:1)^x where x is cross no.
For mono hybrid cross, cross no.=1
For dihybrid cross, x = 2 …. so on
1) Phenotypic & genotypic ratio remains same for reciprocal cross.
2) By exchanging parents, there’s no change in phenotypic or genotypic ratio.
Both statemnets are correct & 2 maybe regarded as correct explanation of 1.
As, cross obtained by exchanging the parents is K/a reciprocal cross.
Whats back-cross?
Cross of f1-generation with its parents.
Back-cross = f1 x parent
F1 x dominant parent =
F1 x recessive parent =
F1 x dominant parent = out-cross
F1 x recessive parent = test-cross