Genetics exam 2 Flashcards
A eukaryotic dipliod cell from an organism with the ZZ-ZW sex determination system has two pairs of autosomes and a pair of sex chromosomes, Z and W. The individual from which this cell came is
a. male.
c. hermaphrodite.
b female.
d. monoecious.
Female
In the individual above, what is the probability of a gamete from this individual with an a, b, W genotype? (use the addition or multiplication rule)
1/2
¼
1/6
1/8
1/8
In the case of F plasmid conjugation ____ are the recipient cells and______ are the donor cells with conjugation machinery in the main chromosome.
F+, F-
F-, F+
F-, Hfr
F-, Hfr
During which phase of mitosis do the sister chromatids separate toward opposite poles?
a. Prophase
b. Prometaphase
c. Telophase
d. Anaphase
d. Anaphase
The general purpose of the synaptonemal complex is to…
a. Provide a link between homologous chromosomes in meiosis prior to crossing over and forming chiasmata
b. Enable the reformation of the cell wall during cytokinesis
c. Separate the sister chromatids during anaphase
d. Independently assort the chromosomes during metaphase of meiosis
a. Provide a link between homologous chromosomes in meiosis prior to crossing over and forming chiasmata
In human blood types, the fact that an individual can have an AB blood type is an example of
a. Incomplete dominance
b. Incomplete Penetrance
c. Sex-influenced trait
d. Codominance
d. Codominance
You have crossed two flower beetles with odd patterns on their wings. You know the coloration is due to one locus. A homozygous black beetle (BB) is crossed with a red streaked homozygous beetle (bb) and you got all Bb. You crossed the Fl generation heterozygotes and got some odd results. From a total of 3194 beetles, you got 1916 black beetles ,1278 red streaked beetles
a. Incomplete penetrance
b. Mendelian inheritance of two traits and two genes
c. Recessive epistasis, two genes with one trait
d. Gene redundancy
Incomplete penetrance
When two individuals with the same phenotypic trait mate and have offspring lacking the trait because they had separate genes causing the same phenotypic trait but the negative trait canceled out it is called? (two blind people having a child with site)
a. Complementation
b. Phenotypic plasticity
c. Total penetrance
d. Pleiotropy
a. complementation
Which of the following would contain genetic material that is 100% (or 99.99999%) identical
a. Homologous chromosomes
b. Sister chromatids
c. X and Y chromosomes
d. All of the above
b. sister chromatids
Retrotransposons have a(n) _____ intermediate.
a. DNA
b. RNA
c. Protein
b. RNA
Some of the first gene maps in bacteria were created by allowing _____ to take place, then stopping it with a blender and using selective media to determine which genes had moved between organisms.
a. Conjugation
b. Dosage compensation
c. Transformation
d. Transduction
a. Conjugation
Match the organism with the most appropriate statement regarding sex determination.
Bird
Drosophila
Human
Turtle
A. The male chromosome is smaller than the female chromosome
B. Males are homogametic
C. Number of X chromosomes determines sex
D. Temperature is involved in sex determination
Bird = B
Human = A
Drosophila = C
Turtle = D
If an allele is dominant in one sex and recessive in another it is an example of
a. Sex limited inheritance
b. Incomplete dominance
c. Sex influenced inheritance
d. Simple mendelian inheritance
Sex influenced inheritance
In a dihybrid cross of two heterozygous individuals, vou expect a 9:3:3:1 phonotypic ratio in the offspring, but observe a ratio of 9:7. What is the most likely explanation?
Codominance
Sex limited trait
Incomplete penetrance
Epistatic interactions of the two genes
Epistatic interactions of the two genes
Which of the following are dosage suppression mechanisms? Please select all that apply.
X-inactivation
Y over expression
X over expression
RNA inactivation
X under expression
X-inactivation
X under expression
X over expression
Haplodiploidy in scale insects happens due to
Unfertilized eggs become males
Dosage compensation creates haploid males
Paternal Genome Elimination in males
Paternal Genome Elimination in males
In 1959, the French physician Jérôme Lejeune identified Down syndrome as a chromosomal condition. Lejeune observed _ chromosomes in the cells of individuals with Down
syndrome.
46.
48
49
47
47
In the case of human oocyte development, meiosis is arrested in Prophase I for
days
months
years
indefinitely
years
Gene transfer via transduction occurs when _____ infect____
plasmids, viruses
viruses, bacteria
bacteria, humans
viruses, bacteria
Hemophilia in humans is due to an X-chromosome mutation. What will be the results of mating between a wildtype (non-carrier) female and a hemophiliac male?
Half the daughters are wildtype, half the sons are hemophiliac.
All the sons are wildtype, and all daughters are carriers
All the daughters are wildtype, and all the sons are carriers.
All the sons are wildtype, and all daughters are carriers
In a cross between a white-eyed female fruit fly and a red-eyed male, what percent of the female offspring will have white eyes? (White eyes are X-linked recessive)
100%
25%
50%
0%
0%
Antibiotic resistance genes can be passed via
Vertical transmission
Horizontal Transmission - Conjugation
Horizontal Transmission - Transformation
All of the above
All of the above
The Ds locus in corn is responsible for changing color of the corn kernel, but it cannot do it without the locus
Ac
Wx
Sh
All of the loci are needed.
Ac
Transposition was first discovered by
Gregor Mendel
Charles Darwin
Barbara McClintok
Thomas Hunt Morgan
Barbara McClintok
