Question

A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of a cell plate and thus the cell contains more number of chromosomes as compared to other dividing cells. This would result in
A. Aneuploidy
B. Polyploidy
C. Somaclonal variation
D. Polyteny

Answer 1

It is the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes. This kind of organism and cell consists of three or multiple numbers of the haploid chromosome. This type of cell develops as the consequences of the entire nondisjunction of chromosomes during mitosis or meiosis.

Complete Answer:
To answer this question, first, we need to know about the telophase stage of cell division. Telophase is the last phase or fifth of mitosis, it is the process that divides the copied genetic material contained in the nucleus of a parent cell into two alike daughter cells. Telophase starts after the copied, paired chromosomes have been divided and drawn to opposite poles of the cell. During this telophase, a nuclear membrane surrounds every pair of chromosomes to divide the nuclear DNA from the cytoplasm.

Now, let us find the solution from the option.
- Aneuploidy is the presence of an unusual number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46.
- When Nuclear membrane and cell plate is not formed in a cell during telophase of mitosis then the polyploid cell is formed.
- Somaclonal variation is defined as genetic variation observed among progeny of plants regenerated from somatic cells cultured in vitro.
- Polyteny is the condition of a chromosome, nucleus, or cell in which the DNA has repeatedly replicated, without subsequently separating (see endomitosis).

Thus, the correct option is B i.e. Polyploidy.

Note: Polyploids develop when an infrequent mitotic or meiotic catastrophe, like nondisjunction, results in the production of gametes that have a full pair of replica chromosomes. Diploid gametes are quickly produced in this way. When a diploid gamete interacts with a haploid gamete, a triploid zygote develops, even though these triploids are usually not stable and can often be sterile.