They are intact X chromosomes which are highly condensed and transciptionally repressed.
They are intact X chromosomes which are lightly condensed and transcriptionally repressed.
They are intact Y chromosomes which are highly condensed and transcriptionally repressed.
Question 2
Question
What is a condensed inactivated X chromosome?
Answer
X-linked
Y-linked
Barr Body
Question 3
Question
How can a female heterozygote phenotypically display a mosaic phenotype?
Answer
X-chromosome inactivation can phenotypically cause this for X- linked genes to display a mosaic phenotype.
X-chromosome inactivation can phenotypically cause this for X- linked genes to display a mosaic phenotype. This can also occur in males with a XXY genotype.
Y-chromosome inactivation can phenotypically cause this for Y- linked genes to display a mosaic phenotype.
Question 4
Question
Tortoiseshell cats are mostly...
Answer
Female
Male
Homozygous
Heterozygous
Both Female and Heterozygous
Question 5
Question
What's an example of random X-inactivation?
Answer
Tortoiseshell pattern
Down syndrome
Siamese cat
Question 6
Question
What is an example of a reversible epigenetic process?
Answer
Y-chromosome activation
X-chromosome inactivation
Down syndrome
Question 7
Question
What does epigenetic mean?
Answer
Not a change in DNA sequence but a change in chromatin state.
A change in DNA sequence and a change in chromatin state.
Multiple gene sequences are cut out of the X-inactivation
Question 8
Question
X-inactivation is...
Answer
Erased during Mitosis, and the chromosome is passed onto the progeny in its original, active state.
Erased during Meiosis, and the chromosome is passed onto the progeny in an altered state.
Erased during Meiosis, and the chromosome is passed onto the progeny in its original, active state.
Question 9
Question
If extra X chromosomes are inactivated, why does XXY (Klinefelters) produce a clinical syndrome?
Answer
Up to 25% of some x-linked genes in humans escape inactivation. This includes the genes within the pseudoautosomal regions (PARs) of the Y chromosomes.
Up to 75% of some x-linked genes in humans escape inactivation. This includes the genes within the pseudoautosomal regions (PARs) of the X and Y chromosomes.
Up to 25% of some x-linked genes in humans escape inactivation. This includes the genes within the pseudoautosomal regions (PARs) of the X and Y chromosomes.
Question 10
Question
Few genes are shared by both X and Y because...?
Answer
Genes that are unique to the X chromosome are X-linked genes.
Genes that are unique to the Y chromosome are Y-linked genes.
Genes found on the sex chromosomes are sex-linked genes.
All are correct.
Question 11
Question
What type of traits exhibit sex-dependent inheritance patterns?
Answer
X-linked traits
Y-linked traits
Sex linked traits
Question 12
Question
The white gene in drosophila is...
Answer
X linked and is located on the x chromosome
Y linked and located on the Y chromosome
Sex independent
Question 13
Question
What would you call a diploid individual that carries only one copy of a given gene?
Answer
Hemizygous, Hemizygote
Heterozygous, Heterozygote
Homozygous, Homozygote
Question 14
Question
In XX/XY species, the XY sex is________ for X-linked genes.
Answer
Heterozygous
Homozygous
Hemizygous
Question 15
Question
How would you denote a Wild type white allele?
Answer
w-
w+
w
Question 16
Question
Hemizygosity is phenotypically equivalent to...?
Answer
Sex linked
Heterozygosity
Homozygosity
Question 17
Question
X & Y act as a homologous pair during what?
Answer
Mitosis and daughter cell formation
Meiosis and gamete formation
Meiosis II and gamete formation
Question 18
Question
What is a unique aspect(s) of X-linked inheritance?
Answer
XY male parents normally cannot pass their X chromosome to male progeny
A male needs to receive only 1 recessive allele to display the recessive phenotype, but females need to receive 2 recessive alleles.
A heterozygous female for an X-linked trait can produce sons who display the recessive phenotype, regardless of her mate's X-chromosome genotype.
X-linked traits often deviate from Mendelian ratios