Principles Of Inheritence And Variation Flashcards
What is inheritence
Process by which characters are passed on from parent to progeny
What is variation
The degree by which progeny siffer from their parents
From how early humans knew that causes of variation was hidden in sexual reproduction
8000-1000bc
Name an indian breed of animal formed by exploiting artificial selection and domestication
Sahiwal cows in Punjab
Timeline when Gregor Mendel did experiments on garden pea
Seven years(1856-1863)
When was the first time when statistical analysis and maths logic was applied in biology
During Mendel’s investigations
What is a true breeding line
One that has undergone continuous self pollination,shows stable trait inheritence and expression for several generations.
How many true breeding pea varieties Mendel used
14 in contrasting characters
Which were the seven characters used by Mendel
Seed shape,seed colour,pod shape,pod colour,flower colour, stem height,flower position
Which trait is dominant and recessive in flower position character.
Axial-dominant
Terminal-recessive
Which flower colour is dominant and recessive
Purple-dominant
White-recessive
What is called units of inheritence/unit of heredity
Genes
What are alleles
Genes which code for a pair of contrasting traits.
What is a monohybrid
A plant having heterozygous genes for one character only.all other character’s genes are homozygous.
What is a monohybrid cross
A cross between plants having contrasting genes for one character.
What is test cross
Cross between F2 plant and dwarf plant
Law of dominance and law of segregation were based on which type of cros
Monohybrid cross
What is the ne given to law of dominance and law of segregation
Principles or laws of inheritence
What are the postulates of law of dominance
Characters are controlled by discrete units called factors/genes
Factors/genes occur in pairs
In a dissmiliar pair of factors/genes one member of the pair dominates the other
What does law of dominance explain
Expression of only one of the parental character in a monohybrid cross in f1 and expression of both in f2
Also explains 3:1 of f2
What is law of segregation
The factors or alleles of a pair segregate from each other such that a gamete receives only one of the two factors.
What does law of segregation explains
Non blending of characters in progency.that both characters are recovered later.
Give example of incomplete dominance
Inheritence of Flower colour in the dog flower/snap dragon/antirrhinum
Scientific name of dog flower
Antirrhinum
What is incomplete dominance
It is a heterozygous condition in which one of the allele in a pair of genes do not produce any enzyme or produce non functional enzyme
What happens in co dominance
In heterozygous condition both the alleles of pair of genes produce their own products
What is it called when progeny resemble both the parents?
Co dominance
Give an example of co dominance
ABO blood grouping group
Abo blood groups are controlled by which gene?
I gene
How I gene expresses itself.
The plasma membrane of the rbc has sugar polymers that protrude from its surface and the kind of sugar is controlled by the gene.
I^a produce A type of sugars,I^b profuce B type of sugar and i produce no sugar.
How many genotypes of human blood type is possible
Six
How many phenotypes of abo blood group is possible
Four