BIOL 3301 EXAM QUESTIONS AND ANSWERS
LATEST UPDATE (GRADED A+)
In Caenorhabditis elegans (C. elegans), there is an XX and XO system of sex determination. If you are
XX, you are:
a hermaphrodite, meaning that you are both male and female and can fertilize yourself.
In Caenorhabditis elegans (C. elegans), there is an XX and XO system of sex determination. If you are
XO, you are:
a male.
How does the phrase 'you are what you eat' apply to female honeybees?
If female honeybees, which are diploid when fertilized, are given a special diet of royal jelly, females can
turn into queens! But, without royal jelly, females become worker bees.
Male honeybees are haploid (unfertilized), and become:
drones that fertilize the queen.
In the Drosophila model, w+ is the allele for normal red eyes (also called normal, or wildtype). It is:
dominant.
In the Drosophila model, w is an allele of the w+ gene. It causes white eyes due to a failure to make
pigment. It is:
recessive.
Compared to autosomal genes, X-linked genes have different effects in males and females due to:
the differences in chromosome number.
Why might diploid be useful in X-linked genes?
could potentially mask genes that are 'bad'
What are two examples of X-linked disorders?
1) red-green color-blindness
2) hemophilia in the royal family
In sex-chromosome-linked inheritance in humans, why might the number of affected males be greater
than the number of affected females?
Because only one copy of the gene is sufficient to have the disorder.
Females that are clinically unaffected by a gene, but carry a gene mutation based on an analysis of
family history, are known as:
, unaffected carriers.
There are X-linked dominant disorders. Who is affected by these disorders?
males and females
Do any Y-linked disorders exist?
Not many, since there are very few genes on the Y.
What is meiotic nondisjunction?
a situation where chromosomes fail to segregate properly in the two daughter cells
Meiotic nondisjunction can occur in:
autosomes.
Who is affected by meiotic nondisjunction?
males and females
Since genes can come in many allelic forms, different alleles may encode for proteins with different
(or defective) activities. This leads to unique:
phenotypes.
What are the four blood groups?
1) O
2) A
3) B
4) AB
Blood groups are determined by an I gene with what three alleles?
1) I^A
2) I^B
3) i
How the the I^A, I^B, and i alleles specify blood type?
They specify the types of carbohydrate additions that occur on the surface of red blood cells.
Almost everyone has what antigen on their red blood cells?
H antigen (a sugar)
The product of the I^A allele acts on the H antigen to give:
the A antigen.
The product of the I^B allele acts on the H antigen to give:
the B antigen.
LATEST UPDATE (GRADED A+)
In Caenorhabditis elegans (C. elegans), there is an XX and XO system of sex determination. If you are
XX, you are:
a hermaphrodite, meaning that you are both male and female and can fertilize yourself.
In Caenorhabditis elegans (C. elegans), there is an XX and XO system of sex determination. If you are
XO, you are:
a male.
How does the phrase 'you are what you eat' apply to female honeybees?
If female honeybees, which are diploid when fertilized, are given a special diet of royal jelly, females can
turn into queens! But, without royal jelly, females become worker bees.
Male honeybees are haploid (unfertilized), and become:
drones that fertilize the queen.
In the Drosophila model, w+ is the allele for normal red eyes (also called normal, or wildtype). It is:
dominant.
In the Drosophila model, w is an allele of the w+ gene. It causes white eyes due to a failure to make
pigment. It is:
recessive.
Compared to autosomal genes, X-linked genes have different effects in males and females due to:
the differences in chromosome number.
Why might diploid be useful in X-linked genes?
could potentially mask genes that are 'bad'
What are two examples of X-linked disorders?
1) red-green color-blindness
2) hemophilia in the royal family
In sex-chromosome-linked inheritance in humans, why might the number of affected males be greater
than the number of affected females?
Because only one copy of the gene is sufficient to have the disorder.
Females that are clinically unaffected by a gene, but carry a gene mutation based on an analysis of
family history, are known as:
, unaffected carriers.
There are X-linked dominant disorders. Who is affected by these disorders?
males and females
Do any Y-linked disorders exist?
Not many, since there are very few genes on the Y.
What is meiotic nondisjunction?
a situation where chromosomes fail to segregate properly in the two daughter cells
Meiotic nondisjunction can occur in:
autosomes.
Who is affected by meiotic nondisjunction?
males and females
Since genes can come in many allelic forms, different alleles may encode for proteins with different
(or defective) activities. This leads to unique:
phenotypes.
What are the four blood groups?
1) O
2) A
3) B
4) AB
Blood groups are determined by an I gene with what three alleles?
1) I^A
2) I^B
3) i
How the the I^A, I^B, and i alleles specify blood type?
They specify the types of carbohydrate additions that occur on the surface of red blood cells.
Almost everyone has what antigen on their red blood cells?
H antigen (a sugar)
The product of the I^A allele acts on the H antigen to give:
the A antigen.
The product of the I^B allele acts on the H antigen to give:
the B antigen.
