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Why did Mendel study pea plants?
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Define trait.
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Define phenotype.
Define heredity.
List five characteristics of a good model
organism.
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What 7 characteristics did Mendel choose to
study in pea plants?
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True or False: True-breeding organisms produce
identical offspring.
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Matching:
____ P Generation
a.
generation produced asexually by
allowing the hybrid generation to selfpollinate
____ F1 Generation b. hybrid generation produced by cross-
breeding two true-breeding individuals
____ F2 Generation
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Describe Mendel’s first monohybrid test cross and
the phenotypic results he observed in the F1
generation.
After completing a monohybrid test cross for each
of the other six traits and observing the same
pattern of inheritance in the F1 and F2 generations,
what four hypotheses did Mendel develop?
generation made up of two truebreeding individual parents
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c.
When Mendel crossed the F1 plants, what
phenotypic results did he observe in the F2
generation?
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What are alleles?
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In Mendel’s first monohybrid test cross, which
allele was dominant and which allele was
recessive?
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Why do gametes (sperm or egg cells) only contain
one allele for each trait?
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What are heritable characteristics that are passed
from one generation to the next called?
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List four reasons Mendel chose pea plants as
model organisms to study heredity.
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What is cross-pollination?
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The 7 characteristics Mendel studied each had
two contrasting forms or phenotypes. List the two
possible phenotypes for each characteristic:
A Seed shape:
B Seed color:
C Flower color:
D Pod shape:
E
Pod color:
F Flower position:
G Plant height:
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How many alleles does an organism inherit for
each trait?
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Define heterozygous.
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What is a Punnett Square used for?
Define homozygous.
Explain the law of segregation.
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Define genotype.
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True or False: Two different genotypes can
produce the same phenotype.
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True or False: Genotype refers to the genes
responsible for a trait, while phenotype refers to
the actual physical trait an organism exhibits.
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In pea plants the tall allele (T) for height is
dominant and the short allele (t) for height is
recessive. What are the possible genotypes that
would result in a tall phenotype? What is the
genotype that would result in a short phenotype?
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Fill in the Punnett Square below to predict the
possible outcomes of a cross between a
homozygous dominant tall pea plant (genotype TT)
and a homozygous recessive short pea plant
(genotype tt).
Parent A (TT)
T
Parent B (tt)
T
t
t
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What is the only possible genotype the offspring
could have as a result of the above cross?
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What is the only possible phenotype the offspring
could have as a result of the above cross?
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Create a Punnett Square to predict the possible
outcomes of a cross between two tall pea plants
that each has a heterozygous genotype (Tt).
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What possible phenotypes could the offspring
have?
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True or False: A sperm or egg carries only one
allele for each trait because allele pairs separate
from each other during gamete formation
(meiosis).
What possible genotypes could the offspring
have?
True or False: Allele pairs for a trait can be found in
the same locations on homologous chromosomes.
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What is a testcross?
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A tall pea plant is crossed with a short pea plant
and some of the resulting offspring are short.
What must be the tall plant’s genotype?
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What is a dihybrid cross?
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When Mendel crossed two pea plants that were
heterozygous for pea color (Yy; Y= yellow, y =
green) and pea pod color (Gg; G = green,
g=yellow) what were the four resulting
phenotypes of the offspring?
A homozygous dominant tall pea plant is crossed
with a heterozygous tall pea plant. What is the
probability the offspring will be short?
Why did Mendel perform a dihybrid cross?
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In the above dihybrid cross, what is the
probability the offspring will have a yellow pea
with a green pod?
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In the above dihybrid cross, what is the
probability the offspring will have a green pea
with a green pod?
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In the above dihybrid cross, what is the
probability the offspring will have a green pea
with a yellow pod?
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Describe what it means to say that alleles “sort
independently.”
In the above dihybrid cross, what is the
probability the offspring will have a yellow pea
with a yellow pod?
True or False: The outcome of Mendel’s dihybrid
cross indicated that each pair of alleles segregates
independently of other pairs of alleles during
gamete formation.
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What two rules of probability are helpful when
solving genetics problems?
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True or False: A Punnett Square gives you the
actual results of a genetic cross between two
individuals.
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Describe three situations in which simple
Mendelian inheritance patterns do not apply.
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What is pleiotropy?
A plant with the genotype AaBbCc is crossed with
a plant with the genotype AaBbCc. What is the
probability of an offspring having the genotype
aabbcc?
What is the difference between incomplete
dominance and codominance?
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What are some examples of polygenic
inheritance?
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What environmental factors can affect an
organism’s phenotype?
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True or False: Some genes have more than two
possible alleles.
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What is one example of codominance?
True or False: Alleles are always either dominant
or recessive.
Red and white flowering four o’clock plants can
be breed to produce pink flowers. This is an
example of white kind of inheritance pattern?
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True or False: A dominant allele is always the
most common allele found in a population.
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Identical twin brothers are separated at birth. One
is raised in South America and the other in North
America. The brother raised in North America ends
up being 4 inches taller than the brother raised in
South America. What is the most likely explanation
for the difference in height?
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True or False: Only homozygous individuals can
exhibit a recessive genetic disorder.
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What are the chances that two carriers of a
recessive disorder will have a child who exhibits
the disorder?
What are autosomes?
What is a carrier?
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Why are recessive genetic orders more common
in populations where inbreeding has occurred?
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What are two examples of dominant genetic
disorders?
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In humans and other animals, what determines the
sex of an individual?
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How many sex chromosomes do humans
normally have?
Explain the chromosomal theory of inheritance.
How many autosomes do humans normally have?
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True or False: Chromosomes undergo
segregation and independent assortment during
meiosis.
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What are some examples of recessive genetic
disorders?
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True or False: If two individuals who are carriers
of genetic disorders have four children, 1 out of 4
will definitely exhibit the recessive trait.
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What are two examples of sex-linked disorders?
True or False: All dominant genetic disorders are
fatal.
Why do males more commonly exhibit X-linked
disorders than females?
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What is the role of genetic counselors?
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Differentiate between amniocentesis and
chorionic villus sampling.
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Why are newborn babies tested for genetic
disorders?
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Since both males and females exhibit the
disorder, you can infer it is most likely not what
which type of disorder?
What is the purpose of ultrasound and fetoscopy?
How can a pedigree chart be useful in determining
the probability of having a child with a genetic
disorder?
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In this pedigree, the shaded symbols represent
individuals who have an autosomal dominant
disorder. Are individuals 1 and 3 in generation I
heterozygous or homozygous?
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If individuals 7 and 8 in generation II had another
child, what is the probability that child would
exhibit the disorder?
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If individuals 1 and 2 in generation III had another
child, what is the probability that child would
exhibit the disorder?