Genetics ReviewPart 2

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

What are the X and Y chromosomes called?

•Sex chromosomes

What are chromosomes pairs1-22 called?

•Autosomes

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 Trisomy 21

What is the gender of this karyotype?

Male

Is this karyotype considered “normal”?

No

How many blood types are there?

•A•B•AB•O

How many alleles do you have for blood type?

•2

Blood types A and B are expressed equally; they

are

•codominant

If 2 people have AB blood, what is the

probability they will have an offspring with

AB•50%

What is true about the Y chromosome compared

to the X?

It is shorter than the X

What causes an organism to receive too

many or too few chromosomes?

•nondisjunction

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

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

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

Males have the sex chromosomes…

XY

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?

Which parent determines the gender of the child?

Father

What is any characteristic passed

from parent to offspring?

•A Trait

How do we represent the allele for a recessive

trait?

•Lowercase letter

A section of a chromosome that codes

for a trait is a

•Gene

What is the likelihood that a particular event

will occur?

•Probability

What is the genetic makeup of an organism

called?

•Genotype

The branch of Biology that deals with heredity

•Genetics

Passing of traits from parent to offspring

•Heredity

An allele that expresses itself in a hybrid is

a(n)_________.

•Dominant allele

All of the possible results of a genetic cross

can be shown by using what tool?

•Punnett Square

What is the term for the physical appearance

that an organism expresses?

•Phenotype

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