Download Dominant trait

Md. Kawsar Ali Hawlader
Senior Lecturer
Dept. Of Biology
Sub:Biology Second Paper
Chapter – 11
Genetics and Evolution
Genetics
After reading this lesson students should be able to…
 tell the definition of genetics
 tell the definition of heredity
 explain the various terms of this lesson.
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Genetics
Inheritance
Mendel
Gene
Allele
Dominant character
Recessive character
Genotype
Phenotype
Homozygous
Heterozygous
Test-cross
Back-cross
Genetics
• Willium Betson introduced the
word‘Genetics.’.
Heredity
Heredity is the transmission
of characters from one
generation to next.
Gene
Fragmentation
of DNA
which is
responsible for
character of
organism.
Allele
Two or more
alternative form of
a gene present in
a locus of
homologous
chromosome are
called allele.
Dominant trait:
Of the two alternating
forms of a trait , the one which appears in the F1
hybrid is called dominant trait.
Recessive trait: Of
the two alternating
forms of a trait, the one which suppressed in the
F1 hybrid is called recessive trait.
Homozygous
An individual
possessing identical
alleles for a trait is
called homozygous.
Heterozygous
An individual
receiving dissimilar
alleles for a trait is
called heterozygous.
Monohybrid cross
Dihybrid cross
The cross between
two parents differing
in a single pair of
contrasting characters
is called monohybrid
cross.
The cross between two
parents in which two
pairs of contrasting
characters are
considered is called
dihybrid cross.
Test cross
An experimental cross
of individual organism
dominant phenotype
but unknown genotype
to an organism with a
homozygous recessive
genotype is called test
cross.
Back cross
It is a crossing of
a hybrid with one
of its parents is
called back cross.
TEAM
WORK
Group - A
Write down the
definition of genetics,
heredity, homozygous,
heterozygous and testcross.
Group-B
Write down the definition
of phenotype, genotype,
allele, dominant character
and back- cross.
a. Who is the father of genetics?
b. What is meant by genetics
c. What is phenotype?
d. What is genotype?
e. What is dominant character?
f. What is recessive character?
• Make a short note on the various terms on
genetics.