Question 1

Species I is diploid (2n = 6) with chromosomes AABBCC; a related species II is diploid (2n = 6) with chromosomes MMNNOO. Indicate the chromosomes that would be found in individuals with the following chromosome mutations.
a. trisomic for chromosome A
b. tetrasomic for chromosome N
c. an autotriploid of species I
d. an allotetraploid
e. an autotetraploid of species II
f. monosomic for chromosome B
g. a double trisomic for chromosomes A and C
h. a nullisomic for chromosome O

Accepted Answer

The answer of Species I is diploid (2n = 6)...

Question 2

Most strains of cultivated bananas were created by crossing plants within and between two diploid species: Musa acuminata (genome = AA) and Musa balbisiana (genome = BB). The Cavendish banana (genome = AAA), the variety most often sold in grocery stores, has what type of genome?

Accepted Answer

The Cavendish banana has a genome of AAA, which means it is an autotriploid, having three sets of chromosomes from the same species, Musa acuminata.

Question 3

Species A and B are closely related. Species A has 2n = 12 chromosomes, and species B has 2n = 14 chromosomes. Chromosome numbers (2n) for the following related species are thought to have arisen through polyploidy. For each species, indicate what type of polyploid it is, and how it may have formed.
a. Species C 18
b. Species D 24
c. Species E 26
d. Species F 28
e. Species G 36
f. Species H 52
g. Species I 56

Accepted Answer

The answer of Species A and B are closely related....

Question 4

Most strains of cultivated bananas were created by crossing plants within and between two diploid species: Musa acuminata (genome = AA) and Musa balbisiana (genome = BB). Some bananas have genome AAB, which is an example of which kind of polyploidy?

Accepted Answer

The genome AAB indicates that the banana is a triploid with two sets of chromosomes from Musa acuminata (AA) and one set from Musa balbisiana (B), making it an allotriploid.

Question 5

A plant species has 2n = 18 chromosomes. How many chromosomes would you expect to find in a tetrasomic individual of this species?

Accepted Answer

A tetrasomic individual has an extra pair of homologous chromosomes, so it would have 2n + 2 chromosomes. For this species, 2n = 18, so a tetrasomic individual would have 18 + 2 = 20 chromosomes.

Question 6

A newly discovered species of dung beetle has 2n = 16 chromosomes. It mates with a closely related beetle species that has 2n = 12 chromosomes. How many chromosomes would there be in an allotriploid beetle produced from this cross?

Accepted Answer

The answer of A newly discovered species of dung beetle...

Question 7

Explain the genetic basis for sterility in autopolyploid organisms.

Accepted Answer

The answer of Explain the genetic basis for sterility in...

Question 8

A newly discovered species of dung beetle has 2n = 16 chromosomes. It mates with a closely related beetle species that has 2n = 12 chromosomes. How many chromosomes would there be in an amphidiploid beetle produced from this cross?

Accepted Answer

An amphidiploid organism is formed when two different species hybridize and then undergo chromosome doubling. The first species has 16 chromosomes (2n = 16) and the second has 12 chromosomes (2n = 12). The hybrid would initially have 14 chromosomes (n = 8 from the first species and n = 6 from the second). After chromosome doubling, the amphidiploid would have 28 chromosomes (2n = 28).

Quiz 8: Chromosome Variation

Most strains of cultivated bananas were created by crossing plants within and between two diploid species: Musa acuminata (genome = AA) and Musa balbisiana (genome = BB) . The Cavendish banana (genome = AAA) , the variety most often sold in grocery stores, has what type of genome?

Most strains of cultivated bananas were created by crossing plants within and between two diploid species: Musa acuminata (genome = AA) and Musa balbisiana (genome = BB) . Some bananas have genome AAB, which is an example of which kind of polyploidy?

A plant species has 2n = 18 chromosomes. How many chromosomes would you expect to find in a tetrasomic individual of this species?

A newly discovered species of dung beetle has 2n = 16 chromosomes. It mates with a closely related beetle species that has 2n = 12 chromosomes. How many chromosomes would there be in an allotriploid beetle produced from this cross?

Explain the genetic basis for sterility in autopolyploid organisms.

A newly discovered species of dung beetle has 2n = 16 chromosomes. It mates with a closely related beetle species that has 2n = 12 chromosomes. How many chromosomes would there be in an amphidiploid beetle produced from this cross?