Chapter 12 Genetics Review

If a characteristic is sex-linked, 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

XBXb XBY

XbXb XbY

XB

Xb

Xb Y

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?

XrY

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

XBXB

Y

XB XBXB

XBYB XBY

XB XB

XBXB

Y

XB XBXB

XBY XBY

XB Xb

XBXB

Y

XB XBXB

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

XX XX

XY XXY

X

X X

XX XX

XX XYY

X

X X

XX XX

XY XYY

X

_____________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 fibrosis1. 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 fibrosis1. 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