Transcript Hot Seat - Inheritance Patterns

Inheritance Patterns
Hot Seat
The phenotype of a guinea pig’s hair
color can best be determined by
a.
b.
c.
d.
Test cross
Looking at the guinea pig
Pedigree chart
Knowing the genotype of the mother pig
If a trait that is visible in the parent organisms is not
seen in the offspring but then returns in the F2
generation, the most probable cause is that this trait in
question is
a.
b.
c.
d.
Recessive
Dominant
Codominant
Mutated
a.
b.
c.
d.
Which of the following genotypes
below shows a pure dominant
genotype?
Aa
aa
AA
AB
Genes that are located at the same
position on homologous chromosomes
are called
•
•
•
•
Recessive
Dominant
Alleles
Homozygotes
In garden pea plants, the offspring formed
from a cross between two heterozygous
tall parents would most likely be
•
•
•
•
25% tall
50% tall
75% tall
100% tall
A pink flower is produced by crossing a plant that has
white flowers with a plant that has red flowers. This
example most likely shows what condition in genetics?
•
•
•
•
Incomplete dominance
Codominance
Dominance
Recessive trait
Who was Gregor Mendel?
• Gregor Mendel was a monk who grew pea
plants to study genetics
What is the difference between a
dominant allele and a recessive allele?
• Dominant allele – capital letter
• Recessive allele – lowercase letter
•
•
•
•
The parents of three girls are
expecting another child, what are the
chances the child will be a boy?
25%
50%
75%
100%
If an colorblind man and a woman who is a
carrier for colorblindness have a child, what
percentage of their female children will be colorblind?
• 0%
• 25%
• 50%
• 100%
•
•
•
•
Which of the following would
represent the sex chromosomes of a
normal female?
XX
XY
YY
XXY
Match the genetic cross of the parents on the left with
the genotypes on the right of the offspring most likely
to be produced from that cross. You may use an
answer choice more than once or not at all.
Genetic Cross
1. BB x bb
2. Bb x Bb
3. BB x BB
4. bb x bb
5. Bb x bb
Predicted Offspring
a. 25% BB 50% Bb 25% bb
b. 100% bb
c. 100% Bb
d. 50% Bb 50% bb
e. 100% BB
f. 75% Bb 25% bb
Match the genetic cross of the parents on the left with
the phenotypes on the right of the offspring most likely
to be produced from that cross. You may use an
answer choice more than once or not at all.
Genetic Cross
1. TT x tt
2. tt x Tt
3. Tt x Tt
4. TT x TT
5. tt x tt
Predicted Offspring
a. 100% short
b. 75% tall 25% short
c. 100% tall
d. 25% tall 75% short
e. 50% tall 50% short
What organisms did Mendel use in his
famous genetic experiments?
•
•
•
•
Mice
Pea plants
Rose plants
Horses
What would be the expected phenotypes
of the offspring from the following cross?
(TT x Tt)
a.
b.
c.
d.
50% tall, 50% short
100% tall
100% short
75% tall, 25% short
What is the name given to a particular cross
used to determine the unknown genotype of an
organism?
a. Test cross
b. Homologous cross
c. Heterozygous cross
d. Target cross
In humans, skin color is controlled by
at least four genes, this is an example
of
a.
b.
c.
d.
Sex-linked trait
Recessive trait
Polygenic trait
Codminant trait
A female that has an allele for color
blindness but not the phenotype for color
blindness would be considered
a.
b.
c.
d.
Color-blind
A carrier for color blindness
Homozygous dominant for color blindness
Homozygous recessive for color blindness
If a human male that is heterozygous for blood type B
has a child with a woman who is heterozygous for
blood type A, what percent of their children can be
expected to have blood type B?
a.
b.
c.
d.
25%
50%
75%
100%
In Mendel’s first experiment, true-breeding plants with
contrasting forms for one trait were crossed. Only one
form appeared in the hybrid F 1 offspring. What did
this show?
• [A] one inheritable unit (element) came from
each parent
• [B] one form was dominant over the other
• [C] the parents were not true breeding
• [D] the traits separate during gamete
formation
After the first experiment described above, Mendel
then self-pollinated the F 1 generation and obtained an
F 2 generation with both parental forms in the ratio of
3 to 1. What additional information did this show?
• [A] the traits separate during gamete
formation
• [B] one inherited unit came from each parent
• [C] the parents were not true breeding
• [D] one form was dominant over the other
How would you describe the P and F 1
plants in Mendel’s first experiment in
modern terms? The P plants were
• [A] heterozygous as were the F 1 plants
• [B] homozygous as were the F 1 plants
• [C] heterozygous and the F 1 plants were
homozygous
• [D] homozygous and the F 1 plants were
heterozygous
Today geneticists refer to Mendel’s
true-breeding parent pea plants as
•
•
•
•
[A] codominant for the traits
[B] dominant for the traits
[C] homozygous for the traits
[D] heterozygous for the traits
An individual’s genotype for an
inherited trait is the
•
•
•
•
[A] set of alleles carried for the trait
[B] family pedigree for the trait
[C] sex of the individual in relation to the trait
[D] physical appearance caused by the trait
Hybrid means the same as
•
•
•
•
[A] homozygous
[B] dominant
[C] mutant
[D] heterozygous
A gene whose effect remains hidden
when it is paired with a different gene
is called
•
•
•
•
[A] mutant
[B] recessive
[C] codominant
[D] dominant
Different genes that affect the same
single trait are called
•
•
•
•
[A] alleles
[B] genes
[C] chromosomes
[D] hybrids
•
•
•
•
An individual in which the two alleles
of a pair that affect a particular trait
are identical is said to be
[A] heterozygous
[B] hybrid
[C] homozygous
[D] dihybrid
•
•
•
•
The genetic makeup of an individual
for a trait being studied is called that
individual’s
[A] phenotype
[B] pedigree
[C] genotype
[D] variability
Let’s say that “A” represents the gene for a dominant
characteristic and “a” its recessive allele. If an Aa
individual mates with an aa individual
• [A] all offspring will show recessive trait
• [B] half the offspring will show the dominant
trait and half will show the recessive trait
• [C] three quarters of the offspring will show
the dominant trait and one quarter will show
the recessive trait
• [D] all offspring will show the dominant trait
How many heterozygous offspring would you expect if
two parents who were heterozygous for a trait
produced an F 1 generation of 40 individuals?
•
•
•
•
[A]5
[B] 10
[C] 15
[D] 20
Human blood type is determined by
•
•
•
•
[A] polygenic inheritance
[B] a single gene
[C] linked gene pairs
[D] multiple alleles
What is the relationship between two
unlike alleles of a pair if they both express
their effects on an individual’s phenotype?
•
•
•
•
[A] codominance
[B] linkage
[C] X-linkage
[D] dominance
•
•
•
•
The relationship between the IB allele
for Type B blood and the i allele for
Type O blood is
[A] codominance
[B] different loci
[C] dominant/recessive
[D] unknown
In the AB blood type, the relationship
between the IA allele and the IB allele is
•
•
•
•
[A] X-linked
[B] dominant/recessive
[C] codominance
[D] unknown
Mr. Sandival has Type B blood. Mrs. Sandival has Type
O blood. They have three children of their own and one
adopted child. Owen has Type AB blood, Mary Type O,
Susie Type B, and Carl Type B. Which child is adopted?
•
•
•
•
[A] Susie
[B] Owen
[C] Mary
[D] Carl
A homozygous clover with a “v-shaped” leaf pattern is crossed
with a homozygous clover that has a large pale center to its
leaves. The leaves of every plant in the F1 generation show a vshaped pattern on a large pale center (expressing characteristics
of both parents). This is an example of
•
•
•
•
[A] segregation
[B] breeding
[C] mutation
[D] codominance
Identification bracelets were accidentally removed
from three newborn babies. Blood samples were taken
to help the identification procedures. The blood types
for the babies and their parents were
•
•
•
•
Baby I—Type A Baby II—Type O Baby III—Type AB
Mr. Black—Type A Mr. Brown—Type AB Mr. White—Type O
Mrs. Black—Type B Mrs. Brown—Type O Mrs. White—Type O
Which baby could belong to Mr. and Mrs. Black?
–
–
–
–
•
Which baby could belong to Mr. and Mrs. Brown?
–
–
–
–
•
[A] Baby I
[B] Baby II
[C] Baby III
[D] any of the three
[A] Baby I
[B] Baby II
[C] Baby III
[D] any of the three
Which baby could belong to Mr. and Mrs. White?
–
–
–
–
[A] Baby I
[B] Baby II
[C] Baby III
[D] any of the three
Use the following information to
answer the questions.
•
•
In peas, yellow seed (Y) is dominant to green seed (y), and round seed (R) is
dominant to wrinkled (r).
How many types of gametes could be produced by a YYRr plant?
–
–
–
–
•
How many types of gametes could be produced by a YyRr plant?
–
–
–
–
•
[A]1
[B]2
[C]3
[D]4
[A]1
[B]2
[C]3
[D]4
How many types of gametes could be produced by a yyRR plant, the most
common garden variety of pea?
–
–
–
–
[A]1
[B]2
[C]3
[D]4
If AaBb is crossed with aabb, what proportion of
the offspring would be expected to be aabb?
a.
b.
c.
d.
9/16
1/8
1/4
1/16
If the offspring of a cross show a 9/16 to
3/16 to 3/16 to 1/16 ratio (9:3:3:1), the
parents of the cross have the genotypes
a.
b.
c.
d.
AaBb x AaBb
AaBb x aaBB
aaBb x aabb
aaBb x Aabb
If W = purple flower and w = white,
and D = tall plants and d = short plants,
a wwDd plant would be
a.
b.
c.
d.
purple and tall
purple and short
white and tall
white and short
a.
b.
c.
d.
If aaBb is crossed with AAbb, what
proportion of the offspring will be
Aabb?
1/2
3/16
9/16
1/4
In Summer Squash, the allele for white fruit (W) is dominant over that for
yellow fruit (w). Similarly, the allele for disk-shaped fruit (D) is dominant over
that for sphere-shaped fruit (d). The Punnett square below shows a cross
between two squash plant with genotype ‘WwDd’. How many offspring will
have yellow disk-shaped fruits?
a.
b.
c.
d.
9
3
2
1
In guinea pigs, the allele for black fur (B) is dominant over that for brown fur
(b). Similarly, the allele for short fur (S) is dominant over that for long fur (s).
The Punnett square below shows a cross between two guinea pigs with the
genotype ‘BbSs’. What is the phenotypic outcome of the offspring produced
by this cross?
a. 13 Black short fur, 1 Black long
fur, 1 Brown short fur, 1 Brown
long fur
b. 12 Black short fur, 1 Black long
fur, 1 Brown short fur, 2 Brown
long fur
c. 4 Black short fur, 4 Black long fur,
4 Brown short fur, 4 Brown long
fur
d. 9 Black short fur, 3 Black long fur,
3 Brown short fur, 1 Brown long
fur
What phenotypes and phenotypic ratios would
you expect in a test cross of a pink flowered and
a red flowered snapdragon?
a. 1 white: 2 pink: 1 red
b. 3 red: 1 pink
c. 1 red : 1 pink
d. 2 pink: 1 red
e. 3 pink: 1 red
If a pedigree shows that a human trait seems to
skip generations the trait is probably
__________.
a. Sex linked
b. Polygenic
c. Dominant
d. Recessive
In this pedigree, the shaded individuals are
homozygous recessive. What is the genotype of
individual B?
a. heterozygous
b. homozygous recessive
c. homozygous dominant
d. none of the above
e. can not tell from the diagram
What type of inheritance mechanism—dominant,
recessive, or sex-lined recessive—is shown in the
pedigree? Support your answer with evidence.
• Recessive because it skips a generation and is
present in both males and females
What type of inheritance mechanism—dominant,
recessive, or sex-lined recessive—is shown in the
pedigree? Support your answer with evidence.
• Recessive because it skips a generation and is
present in both males and females
What type of inheritance mechanism—dominant,
recessive, or sex-lined recessive—is shown in the
pedigree? Support your answer with evidence.
• Sex linked recessive because only males are affected.
Mothers of affected males are most likely carriers.
What type of inheritance mechanism—dominant,
recessive, or sex-lined recessive—is shown in the
pedigree? Support your answer with evidence.
• Dominant because the trait is present in each
generation.
A female whose father was red-green colorblind
marries and normal male whose father was also redgreen colorblind. What is the probability that their son
will be colorblind?
a.
b.
c.
d.
0%
25%
50%
75%
*Remember red-green colorblindness is a sexlinked recessive trait.
A female whose father was colorblind marries and
normal male whose father was also colorblind. What is
the probability that their daughter will be colorblind?
a.
b.
c.
d.
0%
25%
50%
75%
*Remember red-green colorblindness is a sexlinked recessive trait.
A woman whose brother has hemophilia is concerned
about passing this trait to her offspring. What is the risk
that she will have a son with hemophilia?
a.
b.
c.
d.
1/8
¼
½
100%
*Remember hemophilia is a sex-linked recessive
trait.
Can a male be a carrier for a sex-linked
disease?
a. yes, if the trait is recessive
b. yes, if the male's father and mother were
carriers
c. no, males have only a single copy of sexlinked genes
d. no way to predict
Achondroplasia is a dominant inherited disorder that causes a
form of dwarfism. The homozygous dominant condition for this
allele is lethal. If one parent is an achondroplasic dwarf, and the
other parent is of normal height, then what proportion of their
children will be expected to be of normal height?
a.
b.
c.
d.
e.
All
½
¼
None
3/4
If a woman who is red-green color blind marries
a man with normal vision, what phenotypes
would you expect their children to have?
a. All their daughters will be carriers and all their sons
will be color-blind.
b. All their daughters will be color-blind, but all their
sons will have normal vision.
c. All their daughters will have normal vision and will
not be carriers, but all their sons will be color-blind.
d. Half of their daughters will be carriers and the other
half will be fully normal, half of their sons will be
color-blind and the other half will have normal vision.
e. All their children will be color-blind
In 1944 Charlie Chaplin was involved in a legal battle over the paternity of a child
born to Joan Berry, a young starlet. The baby was blood type B, the mother A, and
Chaplin O. From what you know about inheritance of blood types, could Chaplin
have been the father of the child? (At the time of the trial, blood group evidence was
not admissible in California courts. Charlie Chaplin was declared responsible for the
child's support).
a. If Chaplin's blood was B, then he must be the
father.
b. No, he could not possibly have fathered the
child.
c. Yes he could of fathered the child.
d. Perhaps, these results are inconclusive.