Transcript Genetics Review Who is the

Genetics Review
Who is the “Father of Genetics”?
Gregor Mendel
What organism did Mendel use
to study genetics?
Pea Plants
Transmission of characteristics
from parents to offspring is
heredity
called ___________________.
Genetics
_____________
is the study of how
characteristics are passed on
from one generation to the next.
Recessive
__________________
= An
allele that IS MASKED BY
the presence of another
allele
The appearance of an organism is
its _____________
phenotype
Another name for heterozygous
hybrid
The diagram at the right
square
is called a Punnett
_____________
Dominant
__________________
= An
allele that MASKS the
presence of another allele
A recessive gene is represented
lower case
by a _________________
letter.
_______________
Alleles
are different gene
choices for a trait.
A dominant gene is represented
by a ____________
letter.
capital
(usually the first letter of the trait)
When both alleles in the pair
are the SAME the organism is
Homozygous
or purebred
______________
When both alleles in the pair are
DIFFERENT the organism is
Heterozygous or hybrid
_________________
A cross that involves only 1 trait
monohybrid
is called a ____________
cross.
Homozygous (HO) or
Heterozygous (HE)?
TT ____
HO
Yy ____
HE
HE
Hh ____
MmHE
____
Ee ____
HE
kk HO
____
HO
BB ____
HO
ZZ ____
Determine the Phenotype:
Pink flowers are dominant to
red flowers
Brown eyes are dominant to
green eyes
Pink
PP _____________
Pink
Pp _____________
Red
pp _____________
Brown
BB ____________
Brown
Bb ____________
Green
bb ____________
For each phenotype, list the
genotype:
Straight hair is dominant to
curly.
Square heads are dominant to
round heads.
SS
SS
____________
straight ____________
square
____________
straight ____________
square
Ss
Ss
ss
ss
____________
curly
____________
round
In guinea pigs, black fur (B) is
dominant over brown fur (b).
If a black Guinea pig is crossed with
a brown Guinea pig and the litter
contains a brown baby, the genotype
of the black parent is probably
BB
Bb
bb
Bb; Must have one B to be black
must have one b to pass on to baby
T = Tall
t = short
The genotype of the
offspring from the
cross at the right is Tt
_________.
tall
Their phenotype is _________.
G
g
G GG Gg
g Gg gg
The parents in this cross
Heterozygous
are _____________
Homozygous
Heterozygous
If G is dominant for green pods and g is
recessive for yellow pods, what percentage of
the offspring will have green pods? _______%
75
R
r
r
Rr
Rr
r
rr
rr
Red throats (R) are
dominant over white
(r)
throats in Goonie
birds.
Make a cross
between a PURE
RECESSIVE and a
HETEROZYGOUS
Goonie bird.
What are the possible
phenotypes of their offspring?
(% and color)
50% red throats
50% white throats
B
b
B
BB
Bb
b
Bb
bb
Make a cross
between two
HETEROZYGOUS
rats.
What are the possible
phenotypes of their offspring?
(% and color)
75 % black eyes
25% red eyes
Black eyes (B) are
dominant over red
eyes (b) in rats.
The parents in this cross
are _____________
Homozygous
Homozygous
Heterozygous
If W is dominant for long wings and w is
recessive for short wings, what percentage of
these offspring will have short wings?
_______%
0%
only ww makes it short
t
t
T
T
Tt
Tt
Tt
Tt
In Reebops curly tails (T)
are dominant over
straight tails (t).
Make a cross between a
HOMOZYGOUS
DOMINANT and a
HOMOZYGOUS
RECESSIVE Reebop.
What is the probability the
offspring will have straight 0%
tails?
All will be Curly tailed (Tt)
P
p
p
P
Pp
Pp
Pp
Pp
What will the offspring be
like?
(% and color)
Purple (P)is the
dominant color for
monsters. Yellow is
recessive (p).
Make a cross
between a
HOMOZYGOUS
purple and a yellow
monster.
100% purple