Download Level Genetics Review

Level Genetics Review
KEY
Describe the 3 laws that Gregor Mendel established after working with pea plants.
a. Law of Dominance: states that the effect of a recessive allele is not observed when a dominant
allele is present. Dominant MASKS the recessive allele.
b. Law of Segregation: states that two alleles for a trait MUST separate when a gamete is formed
(GAMETES are sex cells created during MEIOSIS) Therefore a parent passes only ONE allele for
each trait to offspring.
c. Law of Independent Assortment: Alleles separate and do not have an effect on
another allele.
2. Define the following terms:
a. Dominant- Trait observed and will mask other traits (denoted with Capital letters: T, D, B, R)
b. Recessive- trait that will disappear when a dominant allele is present, only shows up when BOTH
alleles are recessive (denoted with lower case letters: e, b, r, n)
c. Heterozygous-organism is heterozygous for a trait if two alleles are DIFFERENT: Hh, Rr)
d. Homozygous- organism is homozygous for a trait if two alleles are SAME: HH, RR, BB, rr, pp, vv)
Also called PURE
e. Purebred- organisms genotype contains same two alleles (homozygous: HH, TT, bb, rr)
f.
Hybrid-organism that contains two DIFFERENT alleles-heterozygous, Hh, Rr, Tt)
g. Gene-segments of DNA that are found on chromosomes
h. Allele-different types of trait-Hh, BB, rr) always need two per offspring trait)
i.
Phenotype- the way organism looks or behaves
j.
Genotype- the gene combinations an organism contains for a trait.
k. P generation- the PARENT generation
l.
F1 generation- the FIRST generation offspring
m. F2 generation- the second generation offspring
3. In some species of plants, crossing red flowers with white flowers produces pink flowers.
What type of dominance is this called in genetics? Incomplete
4. In some species of chickens, there are two dominant alleles for feather color. What is the appearance of
the offspring when a black dominant rooster is crossed with a white dominant hen? Checked
What kind of dominance is displayed? Co- dominance
5. Some of our traits are determined by more than one pair of alleles,
such as blood type and hair color. What are these types of traits
called? Multiple Alleles
Delete #6
7. If an organism’s diploid number of chromosomes is 36 chromosomes,
what is its haploid number of chromosomes? 18
8. What does a Punnett square show us? Offspring of F1 generation
9. What are the human male gametes? Female gametes?
Sperm
Egg
10. Are the gametes haploid or diploid? haploid
11. How many pairs of chromosomes are found in human body cells? 46
12. How many chromosomes are found in human sex cells? __23___ Are the chromosomes in pairs? no
13. What is the normal male genotype? Normal female genotype?
XY
XX
14. Who determines the sex of the offspring? male
15. What is the probability of having a male or female child? 50%
16. Describe the location of the gene 16p13. OMIT
17. In a certain species of frogs, L is the gene for long legs. The gene for short legs is represented by l.
Two frogs were bred in a lab. A homozygous dominant male and a heterozygous female produced
many offspring.
a. What are the parent phenotypes? Long legs x long legs
b. What are the parent genotypes? LL x Ll
c. What is the phenotypic ratio of the offspring? 4: 0 : 0
d. What is the genotypic ratio of the offspring? 2 : 2
18. In cats, black is dominant to yellow for coat color. Cross a homozygous black cat with a homozygous
yellow cat. B=black, b=yellow
a. What is the genotype of both parents? BB x bb
b. What is the genotype of the offspring? 4:0:0 (4 Bb)
c. What is the phenotypic ratio of the offspring? 4: 0: 0 (all black)
19. Cross a heterozygous brown-eyed man with a heterozygous brown-eyed woman. B=brown, b=blue
a. What is the genotype of both parents? Bb x Bb
b. What is the genotypic ratio of the offspring? 1: 2: 1 (BB, Bb, bb)
c. What is the phenotypic ratio of the offspring? 3:1 (3 black, 1 blue)
20. What are autosomes? The first 22 pair of chromosomes on karyotype
21. What types of traits are controlled by genes located on the sex chromosomes? Sex- linked traits
22. What are homologous chromosomes? Paired chromosomes
23. How many different blood types alleles are there? List them.
3- IA, IB, I (represents A, B, O)
24. What is the universal blood donor? O (has NO ANTIGENS on it)
25. What is the universal blood recipient? AB
26. Fill-in the following Blood Type Chart:
Blood Type
Genotype(s)
Can Give to:
(Phenotype)
A
IAIA or IAi
A, AB
B
AB
O
IBIB
or IBi
IAIB
ii
Can Receive from:
B, AB
AB
A, B, AB, O
A, O
B, O
A, B, AB, O
O
27. If a woman with blood type A has a baby with blood type AB, a man with blood type O could not be the
father.
28. A woman sues a man for the support of the child. She has type A blood, her child has type O blood,
and the man has type B blood.
a. Can he be the father? Yes, if both are carriers for O
b. If the child had type B blood and the man had type O, could he be the father? Explain. No b/c
the neither the mom nor the dad carry the IB allele so the person with O couldn’t be the
dad.
29. A woman with blood type AB marries a man with type O blood.
a. What are the genotypes of each parent? IAIB x ii
b. What are the possible gametes of the woman? IA and IB
c. What are the possible gametes of the man? i
d. Draw a punnett square.
e. What are the phenotypes of the possible offspring?
50% type A and 50% type B
30. Are sex-linked genes found on the X or Y chromosome? X
31. Give 3 examples of a sex-linked trait. Colorblindness, Duchenne’s Muscular Dystrophy, and
Hemophilia
32. A man can only pass his sex-linked gene to his (son/daughter). Circle one
33. Let b=colorblind, B=normal vision
a. Genotype(s) of colorblind male XbY
b. Genotype(s) of colorblind female XbXb
c. Genotype(s) of carrier female XBXb
d. Genotype(s) of normal male
XBY
e. Genotype(s) of normal female XBXB
34. Give the possible genotypes of the parents of a colorblind daughter.
XBXb x XbY
35. Who is more likely to have a sex-linked recessive disorder, males or females? males
36. Hemophilia or “bleeding disease” is due to a recessive sex-linked gene (h). A woman whose father
was hemophilic, but was not a bleeder herself, marries a normal man. What is the chance of
hemophilia being present among her children?
Dad- XhY
Daughter XHXh
Normal Husband XHY
None of their daughters would have it and there is a 50% chance the sons will have it.
37. What is a karyotype, and what kind of genetic disorders can be detected by this procedure? Picture of
chromosomes
38. What does the diagram above represent? Normal male
49. What type of organism is it? Karyotype
40. Does this karyotype show any abnormalities? no
41. Which chromosomes represent the autosomes? 1- 22
42. Which chromosomes represent the sex chromosomes? X and Y
43. How many chromosomes are shown in the karyotype above? 46
44. Describe the karyotype of the following genetic disorders:
a. Down’s syndrome- 3 #21 chromosomes
b. Klinefelter’s syndrome- XXY
c. Turner’s syndrome- only one X
45. Write the genotypes for the following individuals:
a.
b.
c.
d.
Normal male XY
Normal female XX
Turner’s syndrome XO
Klinefelter’s syndrome XXY
The diagrams below represent the sex chromosomes.
A.
46. Is diagram A male or female?
Female
B.
Is diagram B male or female?
Male
THE FOLLOWING PEDIGREE SHOWS THE INHERITANCE PATTERN OF CYSTIC FIBROSIS. USE THE
PEDIGREE TO ANSWER QUESTIONS 47-59.
I
II
III
4
47. How many females are represented in the pedigree? 9
48. How many cystic fibrosis females are found in the pedigree? 3
49. How many normal females are found in the pedigree? 6
50. How many normal males are found in the pedigree? 7
51. How many cystic fibrosis males are found in the pedigree? 2
52. What type of twins (II 6-7) are represented? identical
53. What type of twins (III 3-4) are represented? fraternal
54. Which set of twins do BOTH of the individuals have cystic fibrosis?
Set (II 6-7) or set (III 3-4) II 6- 7
55. Is cystic fibrosis a recessive or dominant gene? recessive
56. What is the genotype of person III-6? ff
57. What is the phenotype of I-1? Cystic fibrosis
58. Is I-3 homozygous recessive, homozygous dominant or heterozygous?
Heterozygous
59. Is I-2 homozygous recessive, homozygous dominant or heterozygous?
Homozygous dominant
Use the words below to answer questions 60- 64:
a. Body
d. Growth and Repair
b. Reproductive
e. 2
c. Gamete
f. 4
60. Mitosis occurs in this type of cell - A
61. The number of cells produced after one mitotic division - E
62. The purpose of cell division during mitosis - D
63. The purpose of cell division during meiosis - B
64. Meiosis occurs in this type of cell - C
65. A male sex cell is called a/an sperm.
66. A female sex cell is called a/an egg.
67. The diploid number of chromosomes in humans is 46.
68. A fruit fly has 8 chromosomes in its body cells. What is the haploid number? 4
69. A dog has 78 chromosomes in its body cells. What is the diploid number? 78