Genetics Test Review
1.
Be able to complete Monohybrid Dominant/Recessive, Incomplete Dominant, Sex-linked, multiple allele, and Di-Hybrid genetic problems including punnett square, genotype and phenotype ratios, parental cross and F1 generation.Dom/Rec: BB = brown Bb = brown bb= blue
Inc. Dom: RR = red R’R’ = white RR’ = pink
Sex linked: X
NX
N= normal female X
NX
n= normal female (but
carrier) X
nX
n= colorblind female X
NY = normal male X
nY =
colorblind male
Mult allele: co-dominant ex. Blood types AA, AO, BB, BO, AB,
OO
Dihybrid: YYRR = yellow round, yyrr = green wrinkled, YyRr =
yellow round
2.
Be able to determine probability using the product and sum rules.“and” multiply the independent probabilities
“or” add the independent probabilities
ie. flip a coin and you get heads and then heads and then tails
½ x ½ x ½ = 1/8
3.
Be able to interpret a pedigree.given a pedigree assign the mode of inheritance (dominant,
recessive, or sex-linked recessive) identify relationships
between individuals and genotype/phenotypes of individuals in
pedigree
4.
Be able to interpret a karyotype.Identify if it is male/female
#23 chromosom if big and big = female big and little = male
identify if it has a disorder (Down’s, Turner’s, & Klinefelters)
5.
GenotypeExpressed physical traits (words like blue eyes)
7.
GeneActual DNA sequence that codes for a particular trait
8.
AlleleAlternate forms of gene (ie. B = brown and b = blue)
9.
Gene lociSpecific place on chromosome where a particular gene is found
10.
HeterozygousHybrid or one of each like Bb or Tt
11.
HomozygousTwo of the same alleles like BB or bb or TT or tt
12.
DominantWill always be the phenotype if present
13.
RecessiveCan only be the phenotype if paired with another recessive
allele otherwise it is masked by the dominant allele.
14.
Co-dominantNeither allele is dominant over the other instead a third or
multiple trait is expressed. Like genotype AB is type AB blood.
15.
Sex-linked traitMeans the gene is only carried on the X chromosome so
therefore passed from mother to son
16.
DihybridTwo traits that are linked and the alleles come together in
gametes (Yr = allele YYRr = genotype)
17.
Multiple alleleExample is blood types where there are more than two
expressions and neither is dominant over the other
Visual representation of chromosomes pairs 1-23 tallest to
shortest and then sex chromosomes (#23) you can determine
gender and chromosomal abnormality
19.
AutosomesChromosome pairs 1-22 control regular traits
20.
Sex chromosomes#23 determine gender and can carry sex-linked traits
21.
Understand how antigens and antibodies help determine blood typing and safe donors.Type AB is universal recipient
22.
Long tailed cats (L) are dominant to cats with no tail (l). Cross a heterozygous female cat with a male cat with no tail. Provide the parental cross, punnett square, genotypic ratio, and phenotypic ratio. If a litter of 12 kittens were produced, how many would have long tails? 6 No tails? 6How many of the F1 generation (out of a litter of 12) could have offspring which would have no tail? all
l l
L
Ll
Ll
l
ll
ll
GR: Ll:ll
PR: 50% long and 50% no tail
23.
In humans, free earlobes (e), (unattached), is inherited as a simple recessive trait. Attached earlobes (E) is the normal (dominant) trait. For the following families, determine the genotypes of the parents.Provide the parental cross and punnett square.
Two parents have 8 children, 4 are normal and 4 have attached earlobes.
Ee X ee
e
e
e
ee
ee
A normal male and a female with free earlobes have 10 children, all are normal.
ee x EE
E
E
e
Ee
Ee
e
Ee
Ee
24.
In lake trout, large fins (F) are incompletely dominant with small fins (F’). The intermediate condition results in medium size fins. Suppose a large finned male is crossed with an intermediate female.Provide the parental cross, punnett square, genotypic ratio, and phenotypic ratio.
FF’ x FF
F
F
F
FF
FF
F’
FF’
FF’
GR: FF:FF’
PR: 50% large fin and 50% intermediate fin
25.
In roses, a cross between plants that produce red roses (R) and white roses (R’) results in pink roses. Provide the parental cross, punnett square, genotypic ratio, and phenotypic ratio.What would be the probability of obtaining a red rose bush in F1?
0% red
What would be the probability of obtaining a pink and then a red rose bush in F1?0
What would be the probability of obtaining a white rose bush in F1?0
RR x R’R’
R’
R’
R
RR’
RR’
R
RR’
RR’
26.
In raccoons, ringed tail (R) is dominant to solid tail. Masked face (M) is dominant to grey face. Predict the outcome of a cross between two raccoons, the female is heterozygous for both traits and the male is a grey faced raccoon with a solid tail.RrMm x rrmm
rm
RM RrMm
Rm Rrmm
rM rrMm
rm rrmm
GR: 1:1:1:1
PR: 25% ringed masked, 25% ringed grey, 25% solid masked,
25% solid grey
27.
Red-green colorblindness is inherited as a sex-linked recessive trait. Suppose a man who has normal vision marries a colorblind woman. Could they have a normal daughter? Yes Explain. Dad gives a NCould they have a normal boy? no Explain mom can only give n
If the same man (normal man) had married a woman who was a carrier, what is the probability of obtaining a colorblind boy? 25%
Of obtaining an offspring that was a carrier? 25%
Of obtaining a carrier female and then a normal boy in two successive births? ¼ x ¼ = 1/16
X
nX
nx X
NY
X
NY
X
nX
NX
nX
nY
X
nX
NX
nX
nY
X
NX
nx X
NY
X
NX
NX
NX
NY
X
nX
NX
nX
nY
28.
A mother has type AB blood and her husband has type B blood. Is it possible to have a daughter that has type O blood? No Why or why not? Mom cannot give an “o”B
O
A
AB
AO
B
BB
BO
29.
A paternity case involves a woman with type A blood and a man with type B blood. The child has type O blood. Is it possible that the man is the father of the child? Yes Show the punnett square that would demonstrate that possibility.AA or AO
BB or BO
B
O
A
AB
AO
O
BO
OO
30.
What blood types are considered universal donors and universal recipients and why?AB is universal recipient because no antibodies
O is universal donor because no antigens
can give to Rh+ but Rh+ cannot give to
Rh-31.
Explain what a sex-linked trait is.Allele or gene carried only on the sex chromosome (X)
32.
What would a normal karyotype look like?23 pairs of chromosomes
Turners
On the 23
rdchromosome
Y’s are small (1X & 1Y) male
X’s are large (2 X’s) female
35.
Use the pedigree below to fill in the following chartsee Hemophilia worksheet
# of generations 3 # of men w/ hemophilia 7
# of normal women 10 # of normal men 6
# of women who are carriers 6 # of women who are XNX- 4 # of couples w/ only 1 child 1 # of people who never married 13
36.
What is genetic counseling? Genetic testing? How could these be used to help couples planning a family?A professional provides information about options related to
possible genetic disorders. Tests can be done to check to see
if the “parents” could be carriers for specific genetic disorders
such as CF or Tay Sachs to name a couple. Parents could use
this information to determine what their next steps could be
in planning a family.
37.
What are the methods to detect abnormalities in utero?Amniocentesis, chorionic villi sampling, ultrasounds
38.
What are options couples have who are at risk for passing on a genetic disorder?