Transcript Document

Chapter 12 Genetics
Review
If a characteristic is sexlinked, it occurs more
frequently in _______.
•Males
What is a diagram that shows
how a characteristic is
passed through a family?
•Pedigree
On a separate sheet of paper
•
•
Draw a pedigree that represents Julie married to
Jeff, with one daughter, Josephine. Josephine
married Joseph and had Jason and Joe. Joe
married Julia and had Shannon and fraternal twin
boys, Mark and Alex. Mark married Alison and had
Ray and Scarlet. Please label the pedigree with the
names of the people.
The individuals in red are affected with an autosomal
recessive disorder. Please indicate the genotypes of
each person in this pedigree
What are the X and Y
chromosomes called?
•Sex chromosomes
The effects of a mutation can
be __________,
_____________,or _________
•Helpful
•Harmful
•Neutral
Mutations are most
commonly
•Neutral
What are mutations?
•Changes in DNA
What is an individual that
doesn’t express a given trait but
can pass it to it’s offspring?
•carrier
Red green color blindness is a sex-linked
recessive trait . In a family the father is
color blind and the mother is a carrier.
Show your work for this cross
Xb
Y
XB
XBXb
XBY
Xb
XbXb
XbY
Red green color blindness is a sex-linked
recessive trait . In a family the father is
color blind and the mother is a carrier.
What is the genotype for the
father?
r
XY
Red green color blindness is a sex-linked
recessive trait . In a family the father is
color blind and the mother is a carrier.
Out of 4 children, how many
girls would be expected to be
color blind?
1
Red green color blindness is a sex-linked
recessive trait . In a family the father is
color blind and the mother is a carrier.
Out of 4 children, how many
boys would be expected to be
color blind?
1
What gender determines the
sex of an offspring?
•Male
What is the gender of this
karyotype?
Male
What genetic condition does
this person have?
Down Syndrome
What is the gender of this
karyotype?
Male
Is this karyotype considered
“normal”?
No
How many blood types are
there?
•A
•B
•AB
•O
What is true about the size of
the Y chromosome
compared to the X?
It is shorter than the X
What is it called when an
organism receives too many
or too few chromosomes?
•nondisjunction
When a fragment of DNA is detached
from a chromosome and then
reattaches in the reverse orientation it is
considered as an_____________.
•inversion
Sex-linked genes refer to
what chromosome?
•X
How many chromosomes
does a person with Down
Syndrome have?
•47
A male can produce sperm
that is either ___ or ___.
•X Y
A mutation caused when a part of a
chromosomes breaks off and attaches to
a non-homologous chromosome
•translocation
If both parents carry the
recessive allele what is the
chance that their child will
inherit the genetic autosomal
condition?
•25%
Which Punnett Square is
worked out correctly?
•
XB
XB
XB
XBXB
XBXB
Y
XBYB
XBY
XB
XB
XB
XBXB
XBXB
Y
XBY
XBY
XB
Xb
XB
XBXB
XBXB
Y
XBY
XbY
What is it called when an
organism receives too many
or too few chromosomes?
•nondisjunction
Which Punnett Square is
worked out correctly?
X
•
X
X
X
X
X
X
XX
XX
X
XX
XX
X
XX
XX
Y
XY
XX
Y
XX
XY
Y
XY
XY
_____________is a mutation
where an organism has an
extra chromosome.
•Trisomy
Based on the pedigree shown, what is the
genotype of person II-7?
Bb
Based on the pedigree shown, how many
Daughters do the original parents have?
1
Sample pedigree - cystic fibrosis
1. What can we say
about I-1 and I-2?
2. What is the
inheritance?
3. What are the odds
that III-5 is a carrier?
4. What is the
relationship between
I-1and III-4?
5. Which individuals are
affected with cystic
fibrosis?
Sample pedigree - cystic fibrosis
1. What can we say
about I-1 and I-2?
2. What is the
inheritance?
3. What are the odds
that III-5 is a carrier?
4. What is the
relationship between
I-1and III-4?
5. Which individuals are
affected with cystic
fibrosis?
Which parent determines the gender of
the child?
Father
Why are there more male children
with hemophilia than female children
with hemophilia?
Hemophilia is linked to the x
chromosome, so males need only 1
recessive gene to get hemophilia
while females need both recessive
genes
What blood type is considered to be the
universal donor? Explain why!
Type O because this
type does not have any
immune antigens on its
red blood cells, can be
given to anybody