Question

Choose the correct answer from the alternatives given.
Match column I with column II and select the correct option from the given codes.

Column I	Column II
A. Autopolyploidy	i. 2n + 1
B. Trisomy	ii. AAAA
C. Allopolyploidy	iii. AABB
D. Nullisomy	iv. 2n 2

a. A-(ii), B-(i), C-(iii), D-(iv)
b. A-(iv), B-(i), C-(ii), D-(iii)
c. A-(ii), B-(iv), C-(iii), D-(i)
d. A-(ii), B-(i), C-(iv), D-(iii)

Answer 1

Hint: Polyploidy is referred to as the abnormal situation where the individual possesses more than 2 sets of paired homologous chromosomes. This usually occurs due to some errors that occur during the cell division mitosis or meiosis. As a result of this, either an extra copy of the chromosome gets added or eliminated thereby altering the normal ploidy of the individual.

Complete answer:
Autopolyploidy is a condition where the individual has an additional set of homologous chromosomes from the same species, that is if the normal chromosome number is 2n this individual will have 4n (AAAA). Unlike normal conditions, autopolyploids possess 3 sets of homologous chromosomes. This condition can be seen in apples.

In the case of trisomy, the individual possesses an extra copy of a chromosome making the total number of chromosomes in them to be 47(2n+1) and not 46 (which is normal). Many of the diseases like Down syndrome, Patau syndrome are caused due to the trisomy of a particular chromosome.

Allopolyploidy is the condition where the individual has 2 or more sets of homologous chromosomes from different species in a cell (AABB). This condition can be seen in plants like wheat. Unlike autopolyploidy which arises from the same species, allopolyploidy arises as a result of hybridization between two different species.

In case of nullisomy, the person lacks a pair of chromosomes. It generally means two chromosomes out of the total 46 chromosomes (n) that are normally present in humans are missing. This condition can be represented as (2n-2).

Hence, the correct answer is option (A).

Note: Polyploidy is mostly common in plants. However, certain highly differentiated tissues in humans like the liver, heart, bone marrow can show polyploidy. This abnormal condition is regarded as lethal in humans causing serious or fatal health conditions.