Exam #3 - Clicker questions Flashcards
An Animal has a diploid chromosome number 20. Which of the following is true?
a) A monosomic CELL has 19 chromosomes
b) A double tetrasomic CELL has 24 chromosomes
c) Both a and b
d) Neither a nor b
c) Both a and b
A monosomic cell has 19 chromosomes
- Monosomy = one homologue is missing
A double tetrasomic cell has 24 chromosomes
- Double trisomy = two different extra homologues are present
Note: these definitions apply to a diploid cell
An animal has a diploid chromosome number of 20. How many chromosomes would a nullisomic GAMETE contain? (Hint remember what nullisomy means)
9, the gamete would have 9 chromosomes
Nullisomy = a pair of chromosomes is missing
A diploid chromosome of 20 will have 10 chromosomes in each haploid, aka gamete. When nullisomy occurs a pair ( two) chromosomes are missing. One chromosome is missing from each haploid, or gamete
In bean plants, 2n = 12. How many different double trisomics are possible?
15 different double trisomics are possible
Double Trisomy = two different homologues are present
In the bean plant you have 6 homologues: 1 2 3 4 5 6 homologue 1 and 2 = one double trisomy 1 and 3 = double trisomy 1 and 4 = " 1 and 5 = " 1 and 6 = " 2 and 3 = " 2 and 4 = " 2 and 5 = " 2 and 6 = " 3 and 4 = " 3 and 5 = " 3 and 6 = " 4 and 5 = " 4 and 6 = " 5 and 6 = "
In bean plants, 2n= 12. How many DIFFERENT chromosomes are there? Assume homozygosity at each locus
There are 6 different chromosomes.
Explanation: There are 12 chromosomes total, but only 6 different chromosomes because there are six pairs of homologous chromosomes
In bean plants, 2n = 12. Which of the following statements are TRUE?
a) A tetrasomic CELL has 16 chromosomes
b) A trisomic GAMETE has 13 chromosomes
c) Both A and B
d) Neither A nor B
d) Neither A nor B
When 2n = 12
A tetrasomic CELL would have 14 chromosomes
A trisomic GAMETE would have 7 chromosomes
A certain plant has a chromosome number of 2n = 10. How many DIFFERENT monosomics are possible
5 different monosomics are possible
For polyploid organisms, x = number of chromosomes per set and n = number of chromosomes in a gamete. A hexaploid organism has 60 chromosomes. Which of the following is correct?
a) x = 10; n = 10
b) x = 10; n = 20
c) x = 10; n = 30
d) x = 20; n = 20
e) x = 20; n = 30
c) x = 10; n = 30
Explanation
Hexaploid
6 sets
6x = 2n = 60
XYY individuals would most likely arise from nondisjunction in
a) meiosis I in mom
b) meiosis II in mom
c) meiosis I in dad
d) meiosis II in dad
D) Meiosis II in dad
Explanation: Because the individual is a male, the non-disjunction would occur in the father since he is the source of the Y chromosome.
The nondisjunction will occur in meiosis II because meiosis I will need to occur normally so that x’s are not passed from father to the individual as well
Which of the following is the result of an abnormal number of chromosomes?
a) Patau syndrome
b) Klinefelter syndrome
c) Edwards syndrome
d) Choices A and B
e) Choices B and C
f) Choices A, B and C
e) Choices B and C
Klinefelter syndrome and Edwards syndrome are results of an abnormal number of chromosomes
Which of the following karyotypes are “written” correctly?
a) 46, X
b) 48, XXY, +21
c) 49, XXXYY
d) Choices A and B
e) Choices A and C
f) Choices B and C
g) Choices A, B and C
f) Choices B and C
A human somatic cell is dividing mitotically. If one chromosome undergoes nondisjunction, what chromosome complement will end up in two daughter cells?
a) 46, 45
b) 46, 44
c) 44, 48
d) 45, 47
45, 47
In humans, faulty tooth enamel is an x-linked dominant trait. A couple with abnormal teeth have a son with Klinefelter syndrome and normal teeth. In which parent did non-disjunction occur?
a) Dad
b) Mom
c) Both Dad and Mom
d) Either Dad or Mom
e) Neither Parent
b) Mom
The offspring is a boy with klinefelter and normal teeth.
Because of his normal teeth, he has recessive x-linked genes the he can only receive from his mother since his father only has x-dominant for abnormal teeth.
Mom Dad
X^FX^F X^fX^f X^FX^F YY
Son
X^fX^f YY
In humans, faulty tooth enamel is an x-linked dominant trait. A couple with abnormal teeth have a son with Klinefelter syndrome and normal teeth. The non-disjunction occurred in the Mother. Which meiosis did the non-disjunction occur?
a) Meiosis I
b) Meiosis II
c) Both Meiosis I and II
d) Either Meiosis I and II
b) Meiosis II
The non-disjunction would occur in Meiosis II. Meiosis I would occur normally, allowing the dominant and recessive X’s separate, then the non-disjunction ( the two recessive X’s not separating) would occur and give the son two recessive X’s.
Which of the following karyotypes would indicate a duplication in the long arm of chromosomes 17?
a) 47, XX or XY, 17 p+
b) 47, XX or XY, 17 q+
c) 47, XX or XY, +17p
d) 47, XX or XY, +17 q
e) none of the above
e) none of the above
