Transcript Unit 2 Jeopardy Genetics 2011

Mendel
Varied Types
of inheritance
Sex Linked and
disorders
Epigenetics
Misc
Organisms that have two
different alleles for a trait are
called …..
ANSWER:
Heterozygous
Name three things a Punnett
square can show
ANSWER:
Genotypes of parents
Possible results of the cross
Possible genotypes of the
children
Explain complete dominance
ANSWER:
When the dominant allele
is present the recessive
allele is masked
Achondroplasia (dwarfism) is caused by
a dominant gene. A woman and a man
both with
dwarfism marry. If homozygous
achondroplasia results in death of
embryos, list the
genotypes and phenotypes of all
potential live-birth offspring.
ANSWER:
2 Aa Dwarfism
1aa Normal
What type of dominance allows
all alleles present to be fully
expressed?
ANSWER:
Codominance
In a family of four, 1 child has
curly hair, 1 child has straight
hair, and 2 children have wavy
hair. Show what the genotypes
and phenotypes of the parents
would have to be.
What kind of dominance is this?
ANSWER:
Parent 1 – genotype Cc
Phenotype – wavy hair
Incomplete dominance
Two newborn babies were
accidentally mixed up at the
hospital. Determine the parents of
the babies by blood type.
ANSWER:
Baby 1 Brown
Baby 2 Smith
What type of
inheritance is shown
by human skin color,
height, eye color, etc.?
ANSWER:
Polygenic
What is the difference between
multiple alleles and polygenic
inheritance
ANSWER:
Multiple alleles – one gene has more
than 2 variants or alleles for a trait
Polygenic – multiple genes ( can be
on multiple chromosomes) all
interact to produce a phenotype
Do men or women express sex
linked traits more often?
Why?
ANSWER:
Men, they have one X
chromosome, thus they
only need one recessive
and it is expressed
What are genetic test performed
on? (What are valid samples?)
ANSWER:
Blood
Skin
Hair
Amniotic fluid
If you mutate a sequence of DNA
which do you alter?
Genome
Epigenome
Proteome
ANSWER:
Genome
Why can an organism produce
more proteins than they have
genes
(Ex 20,000 genes and 120,000
proteins)
ANSWER:
Proteins are made up of various
combinations of polypetides
Genes code for primary structure
Also modification after transcriptions
allows RNA to be “modular” in
function
If two people who are both
carriers for a genetically
inherited fatal recessive disease
decide to become parents, what
will be the odds that their
children will also be carriers?
ANSWER:
50% or 2 out of 4
What attaches to the strand of DNA
to inhibit transcription of the gene
ANSWER:
A methyl group or acetyl
group
When is the epigenome silenced?
ANSWER:
During the first days after
an egg is fertilized
How are histones manipulated to
loosen them up and allow the DNA
to be transcripted?
ANSWER:
Acetyl or methyl groups
attach to them and the
negative charges repel or
attract the histones away
from each other
DAILY
DOUBLE
If the human genome is like a
computer, what is the epigenome
like?
ANSWER:
Computer Software
The alleles for eye color and for body
color are on the X chromosome of
Drosophila, but not on the Y. Red eye
color (w+) is dominant to white eye
color (w), and tan body color (y+ ) is
dominant to yellow body color (y). What
is the genotype of a tan-bodied, whiteeyed male?
ANSWER:
In horses, coat color is often codominant. The
chestnut horse carries two chestnut alleles
(Cc)The palomino horse carries on chestnut
allele (Cc)and one crème allele (Ccr). A horse
with two crème alleles is called a cremello.
A. If you were to breed a chestnut horse with
a palomino what would the offspring be like?
B. What are the possible combinations of
parents to get a cremello horse?
ANSWER:
A. Chestnut (CcCc)Xpalomino(CcCcr)
50% Chestnut 50% Palomino
B. Cremello X Cremello 100% Cremello
Palomino X Cremello 50% Cremello
Palomino X Palomino 25% Cremello
In a dihybrid cross, the
expected ratio in the F2
generation is..
ANSWER:
9:3:3:1
Epigenetics is critical to what
process that occurs during very
early development of the fetus?
ANSWER:
Cell differentiation
What is a test cross?
ANSWER:
A cross between an
dominant phenotype and a
recessive phenotype to
determine the genotype of
the dominant phenotype
If two parents are heterozygous for
a genetically inherited dominant
trait, what is the probability that
they will have a child together who
has this trait in his or her
phenotype?
ANSWER:
75%
If there is a single pair of alleles that
determine the number of toes for an
animal species and homozygous
dominant individuals have 8 toes,
heterozygous ones have 7, and
homozygous recessive ones have 6, the
inheritance pattern would be referred
to as:
ANSWER:
Incomplete dominance
FINAL
JEOPARDY
Baldness in humans is a dominant, sex-influenced trait. This gene is on
the autosomes, not the sex chromosomes, but how it is expressed is
influenced by the person’s sex (due to hormones present, etc.). A man who
is BB or Bb will be bald and will be non-bald only if he is bb. A woman
will only be bald if she is BB and non-bald if she is Bb or bb (it’s almost
like B is dominant in males and b is dominant in females). Actually,
because of the influence of other sex-related factors, most women who are
BB never become totally bald like men do, but rather, their hair becomes
“thin” or sparse.
If two parents are heterozygous for baldness, what are the chances of
their children being bald? Use a Punnett square to illustrate this.
Note: because the sex of a person does make a difference in how the gene
is expressed, you need to set this up as a dihybrid cross to account for the
sex of the children.
ANSWER:
1/8 of the children will be bald daughters,
3/8 will be normal daughters,
3/8 will be bald sons
1/8 will be normal sons;
.