*UPDATED* For 2022-23 Boards Exam
SHOBHIT NIRWAN's
DESIGNED
HEREDITY AND
EVOLUTION
NOTES
, # Genetics -
It deals with
study of heredity and variation .
# Heredity The transmission of characters traits
-
from one generation to
next generation is called Heredity .
# Variations -
The differences in the characters 1 traits among individuals of a
species are called variation .
Causes of Variation
:c
Genetic variations
,
:
mutation (sudden inheritable change in
gene or chromosome )
Environmental factors : →
Diets
→
Chemicals
→
Pollution
Importance of Variation are :
1B It is basis of heredity .
dis Adaptability to adverse conditions is due to variation .
Iii, New varieties of an organism may arise due to variation and form in raw
materials for evolution .
# Inherited Traits These -
are traits characteristics which are based on from
or
to their
parents offsprings generation and are controlled by genes Eg height, .
-
skin colour etc
Johann Mendel Some of the basic laws of inheritance
#
Gregor were proposed by
-
him and he is known to world as the father of
now Genetics .
→ Mendel opted garden pea to conduct his experiments .
→
He selected garden pea for his experiments as -
* these grow quickly
and are easier to study .
can be crossed or self
fig pea plants pollinated .
Several pair of contrasting traits are visible within the same plant round/
wrinkled seeds tall / short plant white / violet flower
, ,
.
# Some Important Terms or
one of different forms of
Allele particular gene eg height
• -
- .
.
-
Dominant Allele An allele whose phenotype will be expressed
-
even in presence
,
of another allele It is represented by capital letter eg T
. . .
•
Recessive Allele Presence of both the allele is must for phenotype to be expressed
-
.
It is represented
by small letter eg:t . .
Genetic composition of an individual eg pure or hybrid tall
Genotype
• -
-
. .
-
Phenotype physical characteristics eg tall or dwarf
-
.
-
.
•
punnet squares probability diagram illustrating the possible offsprings
-
,
.
Chromosomes A
long rod like structure present in nucleus
° - -
.
SHOBHIT NIRWAN's
DESIGNED
HEREDITY AND
EVOLUTION
NOTES
, # Genetics -
It deals with
study of heredity and variation .
# Heredity The transmission of characters traits
-
from one generation to
next generation is called Heredity .
# Variations -
The differences in the characters 1 traits among individuals of a
species are called variation .
Causes of Variation
:c
Genetic variations
,
:
mutation (sudden inheritable change in
gene or chromosome )
Environmental factors : →
Diets
→
Chemicals
→
Pollution
Importance of Variation are :
1B It is basis of heredity .
dis Adaptability to adverse conditions is due to variation .
Iii, New varieties of an organism may arise due to variation and form in raw
materials for evolution .
# Inherited Traits These -
are traits characteristics which are based on from
or
to their
parents offsprings generation and are controlled by genes Eg height, .
-
skin colour etc
Johann Mendel Some of the basic laws of inheritance
#
Gregor were proposed by
-
him and he is known to world as the father of
now Genetics .
→ Mendel opted garden pea to conduct his experiments .
→
He selected garden pea for his experiments as -
* these grow quickly
and are easier to study .
can be crossed or self
fig pea plants pollinated .
Several pair of contrasting traits are visible within the same plant round/
wrinkled seeds tall / short plant white / violet flower
, ,
.
# Some Important Terms or
one of different forms of
Allele particular gene eg height
• -
- .
.
-
Dominant Allele An allele whose phenotype will be expressed
-
even in presence
,
of another allele It is represented by capital letter eg T
. . .
•
Recessive Allele Presence of both the allele is must for phenotype to be expressed
-
.
It is represented
by small letter eg:t . .
Genetic composition of an individual eg pure or hybrid tall
Genotype
• -
-
. .
-
Phenotype physical characteristics eg tall or dwarf
-
.
-
.
•
punnet squares probability diagram illustrating the possible offsprings
-
,
.
Chromosomes A
long rod like structure present in nucleus
° - -
.
