In: Biology
A popular variety of coffee, Coffea arabica, is a tetraploid plant with 44 chromosomes per somatic cell. What would be the chromosome number in the following Coffea arabica variants:
a. A diploid variant
b.A nullisomic variant
c. A Robertsonian translocation variant
d. A reciprocal translocation variant
Given that the tetraploid plant has 44 chromosomes, means 4n = 44 or n =11
A- In the diploid variant, there will 2n chromosomes which means that diploid plant has 22 chromosomes.
B- Nullisomic Variant- It is a condition when one set of the diploid chromosome is deleted from the plant in case of the diploid plant. So in case of the tetraploid plant, there will be a loss of 4 chromosomes
So the answer is 44-4 or 40 chromosomes
C- In case of Robertsonian translocation two acrocentric chromosomes joined at their centromeric region. Since nothing is given about the chromosome of Coffea arabica so we can assume that the number of chromosomes in the A Robertsonian translocation variant will be same as that of tetraploid plant i.e. 44
D- A reciprocal translocation is a translocation in which one part of the chromosome is transferred to second chromosomes and some of the second chromosomes are translocated in the first chromosome. So answer is will be 44 chromosomes