GENETICS Practice

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GENETICS Practice

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G g
The parents in this cross are _____________
Homozygous Heterozygous
Heterozygous
G g
GG Gg
Gg gg
If G is dominant for green pods and g is
recessive for yellow pods, what percentage of the
offspring will have green pods? _______
75
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B b
B
b
The genotype of the offspring in the blue box is
_______
bb
The offspring in the blue box is
homozygous heterozygous
homozygous
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In guinea pigs black fur (B) is dominant over
brown fur (b). The Punnett square for a cross
between a HETEROZYGOUS black guinea pig and a
PURE brown guinea pig would look like
B B
b
b
B b
B
B
B b
B
b
B b
b
b
This is the Correct setup Heterozygous
Bb Pure brown bb
homozygous
Another name for pure is _________________
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A o
A AA Ao
B AB Bo
The alleles for blood type show 2 kinds of
inheritance.. The following statements are TRUE
or FALSE?
F A B
are codominant
A is dominant over B. O is dominant over A. A is
dominant over O. B and A are co-dominant A is
incompletely dominant over O. O is recessive to A
and to B
F O is
recessive to both A B

T
T
F
T
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• An organism has the genotype Xy.
• What are the possible sperm it can produce?
• ______ ______

X y
THINK ABOUT IT If females have an XX genotype
and can only give X genes, which parent is the
one that determines whether the baby is a boy or
girl?
Father The mother always gives an X If the
father gives a y, its a boy. If the father gives
an X its a girl.
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• If you cross a homozygous RED flowered four
  oclock plant with a homozygous WHITE flowered
  plant, ALL of the offspring produced have PINK
  flowers.
• This type of inheritance in which the
  heterozygote (Rr) shows a blending of traits is
  called __________.
• A. Dominant/recessive inheritance
• B. Co-dominance
• C. Incomplete dominance

Incomplete dominance
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Red throats (R) are dominant over white
(r) throats in Goonie birds. Make a cross
between a PURE RECESSIVE and a HETEROZYGOUS
Goonie bird.
R r r r

Rr rr Rr rr


50 red throats 50 white throats

• What are the possible phenotypes of their
  offspring?
• ( and color)

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B b B b
Black eyes (B) are dominant over red eyes (b) in
rats. Make a cross between two HETEROZYGOUS
rats.


BB Bb Bb bb

• What are the possible phenotypes of their
  offspring?
• ( and color)

75 black eyes 25 red eyes
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The parents in this cross are _____________
Homozygous Heterozygous
Homozygous
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
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• Who is the Father of Genetics?

Gregor Mendel
Which of the following genotypes could be from a
HETEROZYGOUS organism? TT Rr Ww
bb XX Ss
Rr Ww Ss
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What kind of cross is this? Pure dominant X pure
recessive Heterozygous X heterozygous Heterozygous
X homozygous Hybrid recessive X hybrid pure
Heterozygous X Homozygous
hybrid
Another name for heterozygous is _______________
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In Reebops curly tails (T) are dominant over
straight tails (t). Make a cross between a
HOMOZYGOUS DOMINANT and a HOMOZYGOUS RECESSIVE
Reebop.
T T t t


Tt Tt Tt Tt

• What is the probability the offspring will have
  straight tails?

0 All will be Curly tailed (Tt)
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What type of gametes can this organism produce?
BbTt ______
______ _______ _______
BT bt bT Bt
What type of gametes can this organism produce?
BBTT ______
______ _______ _______
BT BT BT BT
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TtRr X TtRr
TR Tr tR tr
TR
Tr
tR
tr
TTRR TTRr TtRR TtRr TTRr
TTrr TtRr Ttrr TtRR TtRr
ttRR ttRr TtRr Ttrr ttRr
ttrr
Tall T short t R round
rwrinkled
seeds seeds
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• This is an example of a DIHYBRID cross.
• Which pattern of phenotypes will be seen in the
  offspring?

9331
How many offspring will be Short AND Round?
______ Short AND wrinkled? ______
3/16
Recessive and dominant
1/16
Recessive and recessive
HINT9- dominant for both3- recessive and
dominant 3- dominant and recessive 1- recessive
and recessive
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• What do we call the offspring of the F1
  generation?

F2
Which of the following genotypes could be from a
HOMOZYGOUS RECESSIVE organism? TT bb Rr
Ww tt XX aa
bb
tt aa
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A a
A
a
The genotype of the offspring in the blue box is
_______ homozygous heterozygous
heterozygous
How many of the offspring from this cross will
show the dominant characteristic?
¾ (75) AA and Aa
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G g
G GG Gg
g gg
G is dominant for green pods. g is recessive for
yellow pods. What is the genotype of the
offspring in the shaded box?
Gg
What is the phenotype of the offspring in the
shaded box?
Green pods
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• Which of the following is NOT TRUE?
• Genotype determines phenotype
• Alleles are different forms of the same gene.
• Genotype is the way the genes
• make you look.
• Organisms with different genotypes
  can have the same phenotype.

T
T
F
T Tt and TT both look tall
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• What are the 3 different kinds of inheritance you
  learned about?

Dominant/recessive Incomplete dominance Co-dominan
ce
Offspring of the P1 generation are called
______
F1
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What are the possible offspring of a cross
between a blood type AB mom and a type O dad?
A B O O


Ao Bo Ao Bo

• What are the probable blood types of the
  offspring?

50 Type A 50 Type B
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• Which of the following crosses would you expect
  to see a 9331 ratio in the offspring?
• SSYY X ssyy
• SsYy X SsYy
• ssYY X SSyy

SsYy X SsYy 9331 ratio is seen in dihybrid
crosses
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Purple (P)is the dominant color for monsters.
Yellow is recessive (p). Make a cross between a
HOMOZYGOUS purple and a yellow monster.
P P p p


Pp Pp Pp Pp

• What will the offspring be like?
• ( and color)

100 purple
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• What genotype would a PURPLE dad have to be to
  make a yellow monster baby with a Purple (Pp) mom
  monster?

P p
?
?
pp
Pp Dad needs to have a little p to give
one to the baby a big P to be purple
himself
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Wilma and Fred are going to have a baby. Fred in
AA and Wilma is oo. What are the possible blood
types of their baby?
A A o o


Ao Ao Ao Ao
100 will have A type blood
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Wilma and Fred are going to have a baby. Fred in
AA and Wilma is oo. What are the possible blood
types of their baby?
A A o o


Ao Ao Ao Ao
100 will have A type blood
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What type of gametes can this organism produce?
RrTt ______
______ _______ _______
RT rt rT Rt
What type of gametes can this organism produce?
WwGg ______
______ _______ _______
WG wg wG Wg
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FILL IN THE BLANKS WITH THE WORDS
Dominant OR Recessive

• In a DIHYBRID HETEROZYGOUS cross the offspring
  that are
• 9/16 are _______________ for both traits.
• 3/16 are _____________ for one trait and
• _____________ for the other.
• 1/16 are _____________ for both traits.

Dominant
Dominant Recessive
Recessive
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T Tall R red t short r white

• In this cross TtRr X TtRt
• What is the probability the offspring will be
• Tall AND white? ____/16
• Short AND red? ____/16
• Tall AND red? ___/16
• Short AND white? ___/16

3
3
9
1
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T Tall Y yellow peas t short y green
peas

• In this cross TtYy X TtYy
• What is the probability the offspring will be
• short AND green? ____/16
• Short AND yellow? ____/16
• Tall AND green? ___/16
• tall AND yellow? ___/16

1
3
3
9
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Y yellow peas R red flowers y green
peas r white flowers

• In this cross YYRR X yyRR
• Be careful!
• What is the probability the offspring will be
• Yellow peas AND white flowers? ____/16
• Green peas AND red flowers? ____/16
• Yellow peas AND red flowers? ___/16
• Green peas AND white flowers? ___/16

0
0
16
0