Once Upon A Time…
and Happily Ever Afters:
A Review of the
Fundamentals of Genetics
Pinocchio: Truths and Tales
Truth or Tale
Mendel discovered
predictable patterns in
the inheritance of traits.
Truth
Truth or Tale
Plants in Mendel’s P
generation were all
heterozygous.
Tale…
Homozygous
Truth or Tale
A dominant allele masks
or hides the effect of a
recessive allele.
Truth
Truth or Tale
A Mendelian factor is
equivalent to an allele.
Truth
Truth or Tale
Heterozygous individuals
have two of the same
alleles for a particular
gene.
Tale…
different
Truth or Tale
A Punnett square
represents the
phenotype of an
organism.
Tale…
genotype
Truth or Tale
A probability of 1/4 is
equal to a probability of
75 percent.
Tale…
25%
Truth or Tale
The dominant allele for
tallness in pea plants is
represented by the letter
t.
Tale…
T
Truth or Tale
•Mendel performed 82
crosses and documented
all his results.
Tale…
hundreds
Truth or Tale
Genetics is the branch of
biology that involves the
study of how different
traits are transmitted from
one generation to the next.
Truth
Mirror Mirror on
the Wall,
Who Is the Fairest
of Them All?
Who Is the Fairest of Them All?
The scientific study of heredity is called
a. meiosis.
c. genetics.
b. crossing-over. d. pollination.
C
Who Is the Fairest of Them All?
Mendel obtained his P generation by allowing
the plants to
a. self-pollinate. c. assort independently.
b.
cross-pollinate. d.
segregate.
A
Who Is the Fairest of Them All?
What is the probability that the offspring of
a homozygous dominant individual and a
homozygous recessive individual will exhibit
the dominant phenotype?
a. 0.25 c. 0.75
b. 0.5 d. 1.0
D
Who Is the Fairest of Them All?
The first filial (F1) generation is the result of
a. cross-pollination among parents and the next generation.
b. crosses between individuals of the parental generation.
c. crosses between the offspring of a parental cross.
d. self-fertilization between parental stock.
B
Who Is the Fairest of Them All?
Which of the following is the designation
for Mendel’s original pure strains of plants?
a. P c. F2
b. F1 d. F3
A
Who Is the Fairest of Them All?
A genetic trait that appears in every
generation of offspring for Mendel’s
experiments is called
a. dominant.
c. recessive.
b. phenotypic. d. superior.
A
Who Is the Fairest of Them All?
If an individual has two recessive alleles for the
same trait, the individual is said to be
a. homozygous for the trait.
b. haploid for the trait.
c. heterozygous for the trait.
d. mutated.
A
Who Is the Fairest of Them All?
How many different possible phenotypes can be
produced by a pair of incomplete dominant
alleles?
a.
1
c.
3
b. 2
d. 4
C
Who Is the Fairest of Them All?
In humans, having freckles (F) is dominant to not having
freckles (f). The inheritance of these traits can be studied
using a Punnett square similar to the one shown below.
Refer to the illustration to the side. The
genotype represented in box “1” in the
Punnett square would
a. be homozygous for freckles.
b. have an extra freckles chromosome.
c. be heterozygous for freckles.
d. have freckles chromosomes.
A
Who Is the Fairest of Them All?
The difference between a monohybrid cross and a dihybrid cross is
that
a. monohybrid crosses involve traits for which only one allele
exists, while dihybrid traits involve two alleles.
b. monohybrid crosses involve self-pollination, while dihybrid
crosses involve cross-pollination.
c. monohybrid crosses involve one characteristic or gene; dihybrid
crosses involve two characteristic or genes.
d. dihybrid crosses require two Punnett squares; monohybrid
crosses need only one.
C
Who Is the Fairest of Them All?
Which of the following genotypes would you not
expect to find among the offspring of a SsYy x ssyy
test cross:
a.
ssyy d. ssYy
b. SsYy e. SsYY
c.
Ssyy
E
Who Is the Fairest of Them All?
The law of segregation states that
a. alleles of a gene separate from each other during
meiosis.
b. different alleles of a gene can never be found in the
same organism.
c. each gene of an organism ends up in a different
gamete.
d. each gene is found on a different molecule of DNA.
A
Who Is the Fairest of Them All?
The phenotype of an organism
a.
represents its genetic composition.
b. reflects all the traits that are actually expressed.
c.
occurs only in dominant pure organisms.
d. cannot be seen.
B
Who Is the Fairest of Them All?
A reproductive process in which fertilization
occurs within a single plant is ____________
a.
cross pollination c.
self pollination
b. fertilization
d. homo pollination
C
Who Is the Fairest of Them All?
The transferring of pollen between different
plants is called __________________
a.
cross pollinatin c.
self pollination
b. fertilization
d. homo pollination
A
Who Is the Fairest of Them All?
When two members of the F1 generation are
allowed to breed with each other or self pollinate,
the offspring are referred to as the
____________________ generation.
a.
P generation
c.
F1 generation
b. P2 generation d. F2 generation
F2
Who Is the Fairest of Them All?
In Mendel’s experiments, a trait that disappeared
in the F1 generation but reappeared in the F2
generation was always a ____________________.
a.
dominant c.
homozygous
b. recessive d. heterozygous
B
Who Is the Fairest of Them All?
A phenomenon in which a heterozygous individual has a
phenotype that is intermediate or blend between the
phenotypes of its two homozygous parents is called
____________________.
a. codominance
c. incomplete dominance
b. complete dominance d. intermediate dominance
C
Who Is the Fairest of Them All?
The objective or purpose of Mendel’s experiments
were to study each characteristic trait in hopes of
understanding ____________________________.
a.
b.
pea plants
genetic variation
c.
d.
pea plant DNA
everything
B
Who Is the Fairest of Them All?
A table used to determine and diagram the results
of a genetic cross is called a
____________________.
a.
karyotype
c.
genetic chart
b. punnett square d. matrix
B
Who Is the Fairest of Them All?
____________________ allow for crosspollination to occur.
a.
Fertilizers c.
Breeders
b. Pollinators d. Hybrids
B
Who Is the Fairest of Them All?
The law of independent assortment states that
a. alleles of a gene separate from each other during
meiosis randomly
b. different alleles of a gene can never be found in
the same organism.
c. each gene of an organism ends up in a different
gamete randomly.
d. each gene is found on a different molecule of DNA
randomly.
A
Who Is the Fairest of Them All?
The likelihood that a specific event will occur is
called _____________________.
a.
inheritance
c.
genetics
b. mathematics d. probability
D
Who Is the Fairest of Them All?
In what phase does the law of segregation and the
law of independent assortment apply?
a. mitosis: metaphase
e. meiosis: prophase
b. meiosis: metaphase
f. mitosis: prophase
c. mitosis: anaphase
g. meiosis: telophase
d. meiosis: anaphase
h. mitosis: telophase
D
Rumpelstiltskin: Taking Straw
and Spinning it into Gold
Spin Straw into Gold
(For each pair of bold faced terms circle one of
the terms)Pollination occurs when
______________ is produced in the anther /
stigma (which is the female / male part) is
transferred to the anther / stigma (which is the
female / male part).
Pollen, anther, male, stigma, female
Spin Straw into Gold
List 5 facts about Gregor Mendel’s life and his
experiments that influenced our knowledge of
genetics.
Answers will vary depending on what
you want to remember about Mendel
• Refer to notes for assistance
Spin Straw into Gold
Carrion beetles lay their eggs in dead animals and
then bury them in the ground until they hatch.
Assume that the preference for fresh meat (F) is
dominant to the preference for rotted meat and
that the tendency to bury the meat shallow (S) is
dominant to the tendency to bury the meat deep.
Suppose a female carrion beetle homozygous
dominant for both traits mates with a male
homozygous recessive for both traits. What will be
the genotypes and phenotypes of the F1
generation?
FfSs – Fresh Meat and Shallow bury
Spin Straw into Gold
Rumpelstiltskin meets a strong-willed fair maiden
(Belle) who makes him see the error of his ways. They
marry and decide to have lil stiltskins. Rumpelstiltskin
has green body color and is heterozygous for spinning
straw into gold. Belle is heterozygous for pale body
color but has no ability to spin straw into gold. The
couple knows that a child that spins straw into gold will
be financially secure for the rest of his/her life. (in other
words they will not need to live off Rumpel and Belle)
Rumpelstiltskin and Belle want to know the odds that
their child will have the ability to spin straw into gold.
There is a 50% chance that
Rumpelstiltskin and Belle will have
a child that can spin straw into
gold.