Genetics Test Study Guide

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Genetics Test Study Guide

• 11/16/07

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Know definitions for following words 1.
pedigree- tool for tracing a trait through a
family 2.heterozygous- an organism with two
different alleles for a trait 3. genotype-
genetic makeup of an organism 4. phenotype-
physical appearance of an organism 5.
probability- helps determine the chance that
something will occur
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6. incomplete dominance- when an intermediate
form is expressed in offspring 7. multiple
alleles- when more than two alleles control a
trait 8. polygenic inheritance- when a group of
gene pairs act together 9. punnett square- a
genetics tool that uses letters to represent
dominant and recessive alleles 10. homozygous-
when there are two alleles that are exactly the
same 11. heredity- passing of traits from
parents to offspring
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12. dominant factor- a factor that covers up
another factor 13. recessive factor a factor
that seems to disappear 14. alleles- the
different forms a gene has for a trait 15.
genetics- study of heredity 16. Homozygous
traits will look like two upper case letters or
two lower case letters TT ,tt 17.Punnett square
shows you all the ways alleles combine
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18. Human blood types- A, B, AB and O 19.
Blood type is controlled by 3 alleles
20. Capital letters stand for
and lower case stands for a 21. Recessive
genetic disorder examples are 22. Mendel
called plants that received different alleles for
a trait from each parent a 23. Father of Genetics
is
dominant trait
recessive trait
cystic fibrosis and hemophilia
hybrid
Gregor Mendel
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24. Purebred animals that show variations in coat
color is an example of 25. Every sex cell has
alleles for each trait 26. If a human baby
has 2- X chromosomes the baby is a
if it has an X and a Y chromosome it is a 27. A
useful segment of DNA is inserted into a
bacterium to make 28. In,
scientists are experimenting with
methods to change the arrangement of DNA in a gene
incomplete dominance
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girl
boy
recombinant DNA
genetic engineering
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• 29. A purple flower (Pp) and a white flower (pp)
  could produce purple flowers
• Describe the advantage of genetically engineered
  tomatoes.
• They can be picked green and transported great
  distances before they ripen completely, so that
  they are ripe when at the market for purchase
• If a family has four children, 2 girls, 2 boys,
  and only one girl and one boy are colorblind, are
  their parents colorblind?
• The father is colorblind and
  the mother is a carrier

2
Xc Y
Xc XcXc XcY
X XcX XY




Xc
Y
x
Xc
XcXc
XcY
X
XcX
XY
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32. Who is more likely to be colorblind, girls or
boys? 33. Offspring with homozygous alleles
received how many alleles from each parent? 34.
What possible genotypes will the offspring have
if the parents blood types are O and AB?
32. Who is more likely to be colorblind, girls or
boys? 33. Offspring with homozygous alleles
received how many alleles from each parent? 34.
What possible genotypes will the offspring have
if the parents blood types are O and AB?
boys
one
AO or BO
x


A
B
O
AO
BO
O
AO
BO
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• Why do cystic fibrosis patients have to have
  their backs pounded on as part of their therapy?
• to break the mucus in their lungs to breathe
  easier

36. One day it will be important for scientists
to correct damaged genes in babies before they
are born. Why? It may result in a genetic cure
for the disorder 37. is one
disease that is already being treated by use of
recombinant DNA, a method of genetic engineering.
Diabetes
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• 38. You are looking at four purple flowers. What
  are their phenotypes and genotypes?
• Phenotype is purple and just by looking you
  could not tell their genotypes but it could be PP
  or Pp
• is when you
  select plants or animals with the most desired
  traits to breed for the next generation.
• 40.
  is when a normal allele is placed into a
  virus, which delivers it when it infects its
  target
• cells.

Selective breeding
Gene therapy
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41. Name traits that are a result of polygenic
inheritance. human height, human eye color,
human skin color, human hair color, grain color
in wheat, milk production in cows, egg production
in chickens 42. Why was Mendels predictions for
dominant and recessive traits so accurate?
He worked with a large number of plants (over
30,000) and concentrated on one trait at a time
and he kept a record of the results. 43. How can
Punnett Squares predict results of crossbreeding
in plants? It shows all the ways in which
alleles for a particular trait can be combined
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44. How many crosses of red and white
four-oclock flowers would you need to find out
all the possible phenotypes for color of flowers?
You would need 2, the first cross would be
red with white and the second cross would be pink
with pink which would give you red, white and
pink phenotypes 45. Write a pedigree for a family
(parents and four children) in which one girl and
one boy are color-blind while one boy and one
girl are not.
x


Xc
Y
Xc
XcXc
XcY
X
XcX
XY
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46.If two people are heterozygous for sickle
cell anemia, what are the chances that their
children will have the disease? S non sickle
cell anemia and s sickle cell
anemia __________________________________________
_______________________ __________________________
__________________________________________________
__________
x


x S s
S
s
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47. Family pedigree of color-blindness. How
is the disease inherited?
Disease is sex linked and inherited on the X
chromosome. Mother is a carrier.