Download laid the foundation of genetics through his work on garden peas

Genetics
A trait is:
a characteristic of
an
organism- shape,
color and size.
Offspring
Heredity is:
the passing of traits
from the parents to the offspring.
Genetics is:
the scientific study
of heredity.
A gene is:
a sequence of DNA that
determines a trait.
Where did it all began?
Gregor Mendel:
laid the foundation of genetics
through his work on garden peas.
Garden peas
Mendel’s Law of Segregation
• Parent alleles
separate into different
gametes during
meiosis
Mendel’s Law of Independent
Assortment
Alleles for different
traits separate
independently from
one another.
G=Green
g=yellow
Why can 2 green pea plants
produce a yellow pea plant?
Because they are carrying the
recessive allele!
Gg
Gg
Allele is:
a form of a gene
Mom Dad
Organisms have alleles
for each trait
-two
One from mom/One from Dad
Types of alleles
1.Dominant allele –
the expressed trait or the observable
trait. Ex. RR or Rr
2. Recessive allele –
the trait which is not expressed when
the dominant allele is present. Ex. rr
Homozygous
Example:
Purebred
TT or tt
Heterozygous
Example:
Tt
Hybrid
Identify if the given pair of
alleles is homozygous or
heterozygous.
HH
Homo
Rr
Hetero
Ss
Hetero
aa
Homo
Determine if the given
pair of alleles will show
dominant or recessive
traits.
DD
dominant
Xx
dominant
ww
recessive
Pp
Dominant
Identify the trait from the
given pair of alleles :
If purple flower (P) is dominant
to white flower (p).
What will be color
of the flower?
PP
Purple
pp
White
Pp
Purple
Genotype is:
the gene combination of
a trait.
Example: Ww, TT, Aa, bb
Phenotype is
the physical appearance
of a trait resulting from the genotype.
Example: tall, wrinkled , short,
purple