Transcript Predicting Inherited Characteristics

Predicting Inherited
Characteristics
Gregor Mendel studied
heredity using pea plants.
 His work is the
foundation for
Modern genetics.
Peas Were Used Because:
1. Many traits exist in 2
forms:
Green or yellow
Tall or short
Wrinkled or Nonwrinkled
2. Many offspring were
produced in one
generation
3. They Self-Pollinate:
This would ensure
pure breeding
Mendel’s Conclusions:
1. Individual factors control
inherited characteristics
2. These factors exist in
pairs
3. One factor can
mask or hide another
Genes: Factors that Control
Traits
Factors that control
individual traits are called
alleles.
Some alleles are
dominant, some are
recessive.
Dominant Alleles:
The trait always shows.
Use a capital letter to
indicate dominance
If a dominant allele is
present, a recessive allele
will be masked.
Recessive Alleles
Use a lower case letter to
indicate
Recessive trait will not be
present unless there are 2
recessive alleles.
Blue eyes are recessive
Tongue Rolling
is Dominant
Phenotype
 This is the PHYSICAL EXPRESSION of
a trait
 You CAN see the phenotype
 The dominant allele will ALWAYS show
in a phenotype
Genotype
 This is the GENETIC makeup of a trait
 You can’t see the genotype
Heterozygous
 This means the trait is hybrid
 The organism has a dominant and a
recessive allele for this trait
 Dd – is how this is shown
 ** the dominant trait will always show in
this case **
Homozygous
 This means the trait is pure
 DD or dd
 The organism has two dominant or
recessive alleles for this trait
Purebred and Hybrid
Purebred: Both alleles for a
trait are the same EX: HH,
hh (homozygous)
Hybrid: 2 different alleles for
a trait (heterozygous)
EX: Hh, Tt
Asexual reproduction
 One parent
 Parent divides to produce a copy of
itself
 Offspring is genetically the same as
parent
Sexual reproduction
 Two parents
 Offspring has genes from both parents
 Offspring is genetically DIFFERENT
from parents