GENETICS EXAM 2 COMPREHENSIVE STUDY
QUESTIONS AND ANSWERS
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
b. An autotetraploids of species II..
Answer: 2n=20
or 2X = 20
X = 10
Therefore autotetraploidy =4X
Therefore no. of chromosome = 4X10 =40
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
c. An allotriploid formed from species I and species II..
Answer: Allotriploid formed from species I and II
,There will be n from sp I and 2n from species II
Or 2n from species 1 and n from species 2
First case n from sp. 1 and 2n from sp.2
n = 7+20=27
Therefore chromosome no. will be 2n of this = 27X2=54
Second case 2n of 1 and n of II
n= 14+10=24
no. of chromosome
= 24X2 =48.
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
,d. An allotetraploid formed from species I and species II..
Answer: Allotetraploid from species I and II
2n of I and n of II
14+20=34
No. of chromosome present will be in 2n,
2n = 68.
◉ A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
a. A B E • F G.
Answer: deletion
◉ A chromosome has the following segments, where • represents
the centromere:
, ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
b. A E D C B • F G.
Answer: segment BCDE is inverted 180 degrees; but as the
centromere has not changed position it is PARACENTRIC
INVERSION.
◉ .A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
c. A B A B C D E • F G.
Answer: Tandem duplication of segment AB
◉ A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
QUESTIONS AND ANSWERS
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
b. An autotetraploids of species II..
Answer: 2n=20
or 2X = 20
X = 10
Therefore autotetraploidy =4X
Therefore no. of chromosome = 4X10 =40
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
c. An allotriploid formed from species I and species II..
Answer: Allotriploid formed from species I and II
,There will be n from sp I and 2n from species II
Or 2n from species 1 and n from species 2
First case n from sp. 1 and 2n from sp.2
n = 7+20=27
Therefore chromosome no. will be 2n of this = 27X2=54
Second case 2n of 1 and n of II
n= 14+10=24
no. of chromosome
= 24X2 =48.
◉ Species I has 2n=14 and species II has 2n=20. Give all possible
chromosomes numbers that may be found in the following
individuals:
,d. An allotetraploid formed from species I and species II..
Answer: Allotetraploid from species I and II
2n of I and n of II
14+20=34
No. of chromosome present will be in 2n,
2n = 68.
◉ A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
a. A B E • F G.
Answer: deletion
◉ A chromosome has the following segments, where • represents
the centromere:
, ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
b. A E D C B • F G.
Answer: segment BCDE is inverted 180 degrees; but as the
centromere has not changed position it is PARACENTRIC
INVERSION.
◉ .A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
What types of chromosome mutations are required to change this
chromosome into each of the following chromosomes? (In some
cases, more than one chromosome mutation may be required.)
c. A B A B C D E • F G.
Answer: Tandem duplication of segment AB
◉ A chromosome has the following segments, where • represents
the centromere:
ABCDE•FG
