Download 1 - Humble ISD

UNIT VI STUDY GUIDE
Part I – Vocabulary
1.
______ Both alleles show in heterozygote
2.
______ Autosomal recessive disorder characterized by a lack of melanin production
3.
______ Results from change in DNA; may be harmful, beneficial, or silent
4.
______ 47 XXY
5.
______ Multiple phenotypic effects seen from one gene
6.
______ Idea first proposed by Mendel; alleles for a given gene separate in meiosis
7.
______ Phenotype due to effects of multiple genes
8.
______ Term used to describe cell with abnormal number of chromosomes
9.
______ 45 X0
10. ______ Shows inheritance of a trait through several generations
11. ______ Gene at one locus has a phenotypic effect on gene at another locus
12. ______ Trisomy 21
13. ______ Sex-linked disorder in which blood does not clot properly
14. ______ Genes located on the same chromosome
15. ______ Improper separation of alleles in anaphase I or anaphase II of meiosis
16. ______ Condensed, inactive X chromosome in female somatic cells
17. ______ Neither allele is dominant; heterozygote shows a blending of homozygous phenotypes
18. ______ Autosomal co-dominant disorder affecting hemoglobin structure in red blood cells
19. ______ Term used to describe offspring produced as a result of crossing over
20. ______ Autosomal dominant disorder in which symptoms do not show until 30-40s
21. ______ Photograph of chromosome pairs in metaphase of mitosis; used to detect number disorders
22. ______ Sex-linked disorder characterized by progressive weakening of muscles
23. ______ Scientist credited with first recognizing principles of sex-linked inheritance, linked genes
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
L.
M.
N.
O.
P.
Q.
R.
S.
T.
U.
V.
W.
X.
Y.
Z.
AA.
BB.
CC.
DD.
EE.
FF.
GG.
albinism
aneuploid
Barr body
co-dominance
cystic fibrosis
dominant
Down Syndrome
Duchenne muscular
dystrophy
epigenetics
epistasis
hemophilia
Huntington’s disease
hypercholesterolemia
incomplete dominance
karyotype
Klinefelter Syndrome
Law of Independent
Assortment
Law of Segregation
linked genes
Marfan syndrome
Mendel
Morgan
mutation
nondisjunction
pedigree
PKU
pleiotropy
polygenic
recessive
recombinant
sickle cell anemia
Tay-Sachs disease
Turner Syndrome
24. ______ Autosomal recessive disorder associated with faulty chloride channels; abnormal mucus production
25. ______ Autosomal recessive disorder characterized by inability to metabolize phenylalanine; controlled by diet
26. ______ Term used to describe mutated allele when normal allele protein production compensates; phenotype is unchanged
27. ______ Autosomal recessive disorder in which abnormal lysosomal enzyme function results in lipid accumulation
28. ______ Identified by Mendel; random alignment, separation of maternal versus paternal chromosomes in meiosis
29. ______ Autosomal dominant disorder affecting connective tissue; individuals susceptible to aortic rupture
30. ______ Scientist credited with first understanding genetic principles of diploidy, alleles, heredity
31. ______ Autosomal dominant disorder; abnormal LDL receptors result in high levels of blood cholesterol
32. ______ Term used to describe mutated allele when normal allele protein production does not compensate; altered phenotype
33. ______ Study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence
Part II - Word Problems
1.
An infant with type A blood is born to a mother that is type O blood. What are the possible genotypes for the father?
2.
If a parent has the genotype, AAbbCcDd, identify the different gametes that might be produced and the probability of each occurring.
3.
Polydactyly (extra fingers & toes) is due to a dominant allele. A father is polydactyl, the mother has the normal phenotype, and they have had
one normal child. What is the probability that a second child will have the normal number of digits?
4.
White fruit color in summer squash is governed by a dominant allele (W) and colored fruit by its recessive allele (w). There are two
possibilities for the colored fruit, yellow (Y) and green (y).
a. For the cross, Wwyy X WwYY, what is the probability of yellow fruit?
b.
5.
For the cross, WwYy X green, determine the expected phenotype ratio.
Bronze turkeys have at least one dominant allele, R. Red turkeys are homozygous for its recessive allele, rr. Another dominant gene H
produces normal feathers, and its recessive genotype hh produces feathers lacking webbing, a condition termed “hairy”. In crosses
between true-breeding bronze, hairy birds and true-breeding red, normal-feathered birds, what proportion of the F2 progeny will be
a. Rrhh
b.
bronze, hairy
c.
RrHh
d.
bronze, normal-feathered
6.
A genetic condition on the X chromosome in Drosophila melanogaster is lethal when homozygous in females or hemizygous in males, but
when heterozygous in females produces a purple eye color called “plum”. The other homozygous condition produces wild type eye color. On
chromosome 3, a gene produces short, stubble bristles when homozygous and wild type bristles when heterozygous. A plum- eyed female
homozygous dominant for bristles is crossed with a male with wild type eyes and heterozygous for bristles. What are the expected phenotype
ratios?
7.
In corn, the genes for kernel color and kernel texture are unlinked. Purple kernels are dominant to yellow kernels; smooth kernels are
dominant to wrinkled kernels. In a dihybrid cross, the following offspring are observed, 261 purple and smooth, 79 purple and wrinkled, 65
yellow and smooth, and 21 yellow and wrinkled. Use Chi Square to determine if these numbers are within acceptable limits.
8.
Identify the different gametes that can be produced from the genotypes listed. Calculate the probability of each occurring.
a. Aa Bb CC
b.
9.
Aa bb cc
Identify the expected phenotype ratio of the offspring from Aa Bb CC x Aa bb CC.
10. In pea plants,
a. long stems are dominant to short stems
b. purple flowers are dominant to white
c. round seeds are dominant to wrinkled
A plant that is heterozygous for all three loci self-pollinates and 2048 progeny are examined. How many of the resulting plants would you
expect to be long-stemmed with purple flowers, producing wrinkled seeds?
11. What is the most likely path of inheritance for the pedigree below?
a. Provide the following genotypes:
I-1
I-2
II-4
III-2
IV-2
IV-8
b. Do you notice a possible family secret revealed??!! 
12. For the following pedigrees, identify all possible paths of inheritance and the most probable path of inheritance.
B
C
A
.
E
D
G
F
LINKED GENE WORD PROBLEMS
1.
The locus for pink eyes in Drosophila melanogaster is on the same chromosome as the locus for wrinkled wings. The wild type phenotype is
dominant for both genes. In a test cross using dihybrid flies, the following offspring are observed. How many map units separates the two
loci?
676 wt eyes, wt wings
623 pink eyes, wrinkled wings
124 wt eyes, wrinkled wings
108 pink eyes, wt wings
2.
If AABB is crossed with aabb, and the F1 is testcrossed, what percentage of the testcross progeny will be aabb (ab/ab) if the two genes are
3.
4.
5.
a.
Unlinked?
b.
Completely linked (no crossing over at all)?
c.
10 map units apart?
d.
24 map units apart?
Individuals of genotype AaBb were mated to individuals of genotype aabb. One thousand offspring were counted, with the following results:
474 Aabb, 480 aaBb, 20 AaBb, and 26 aabb.
a.
Identify the alleles on each homologue in the parents.
b.
What are the parental classes of offspring?
c.
What are the two recombinant classes of offspring?
d.
How many map units apart are the two genes?
Genes A and B are 6 map units apart, and A and C are 4 map units apart.
a.
Which gene is in the middle if B and C are 10 map units apart? Draw the chromosome below complete with map unit scale.
b.
Which is in the middle if B and C are 2 map units apart? Draw the chromosome below complete with map unit scale.
Given the following information, draw the chromosome showing correct placement of the genes A, B, C, D, and E.
 A – B = 8 map units
 B – C = 10 map units
 A – C = 18 map units
 B – D = 22 map units
 C – D = 32 map units
 C – E = 30 map units
 D – E = 2 map units