Transcript Genetics Test Study Guide

Genetics Test Study Guide
11/16/07
Know definitions for following words:
1. pedigreetool for tracing a trait through a family
2.heterozygousan organism with two different alleles for a trait
3. genotypegenetic makeup of an organism
4. phenotypephysical appearance of an organism
5. probabilityhelps determine the chance that something
will occur
6. incomplete dominancewhen an intermediate form is expressed in
offspring
7. multiple alleleswhen more than two alleles control a trait
8. polygenic inheritancewhen a group of gene pairs act together
9. punnett squarea genetics tool that uses letters to represent
dominant and recessive alleles
10. homozygouswhen there are two alleles that are exactly the
same
11. hereditypassing of traits from parents to offspring
12. dominant factora factor that covers up another factor
13. recessive factor –
a factor that seems to disappear
14. allelesthe different forms a gene has for a trait
15. geneticsstudy 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
18. Human blood typesA, B, AB and O
19. Blood type is controlled by
3 alleles
20. Capital letters stand for dominant trait and
lower case stands for a recessive trait
21. Recessive genetic disorder examples are
cystic fibrosis and hemophilia
22. Mendel called plants that received different
alleles for a trait from each parent a hybrid
23. Father of Genetics is Gregor Mendel
24. Purebred animals that show variations in
coat color is an example of
incomplete dominance
25. Every sex cell has 2 alleles for each trait
26. If a human baby has 2- X chromosomes the
baby is a girl ; if it has an X and a Y
chromosome it is a boy
27. A useful segment of DNA is inserted into a
bacterium to make recombinant DNA
28. In, genetic engineering scientists are
experimenting with methods to change the
arrangement of DNA in a gene
29. A purple flower (Pp) and a white flower (pp)
could produce 2 purple flowers
30.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
31.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
Xc
Y
x
colorblind and
Xc XcXc XcY the mother is a
X
XcX XY
carrier
32. Who is more likely to be colorblind,
girls or boys? boys
33. Offspring with homozygous alleles
received how many alleles from each
parent? one
34. What possible genotypes will the
offspring have if the parents’ blood
types are O and AB? AO or BO
x
A
B
O
AO BO
O
AO BO
35.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.Diabetes is one disease that is already
being treated by use of recombinant DNA, a
method of genetic engineering.
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
39.Selective breeding is when you select
plants or animals with the most desired
traits to breed for the next generation.
40. Gene therapy is when a normal
allele is placed into a virus, which
delivers it when it infects its target
cells.
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 Mendel’s 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
44. How many crosses of red and white fouro’clock 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
X
Xc
Y
XcXc XcY
XcX
XY
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
S
s
S
s
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.