Question

Which one of the following is used as a marker chromosome?
A. Monocentric chromosome
B. SAT chromosome
C. Idiosome
D. Chromosome

Answer 1

Hint: A chromosome is a lengthy DNA molecule that contains all or a portion of an organism's genetic code. Histones, which act as packing proteins for most eukaryotic chromosomes, collaborate with chaperone proteins to bind to and compress the DNA molecule to maintain the molecule's integrity.

Complete step-by-step solution:
There is greater heterochromatin on the SAT chromosome. A chromosomal fragment that is divided from the chromosome's main body by such a secondary constriction is known as a satellite chromosome or SAT chromosome.
At metaphase, a chromatin filament seems to connect the satellite to the remainder of the chromosomal body. The chromosome is referred to be a nucleolar satellite chromosome if the secondary constriction includes the nucleolus organizer region. Each diploid nucleus has at least 2 SAT chromosomes. They are essential for the nucleolus to develop when cell division is finished.
Chromosomes with secondary structures that act as identifying markers are known as satellite chromosomes. Some chromosomes exhibit one or more additional constrictions at metaphase in addition to the centromere.

Satellite chromosomes are referred to as SAT chromosomes. Satellite chromosomes include chromosomes 13, 14, 15, 21, and 22. SAT-chromosomes with secondary constriction connected to nucleolus development are known as nucleolar SAT-chromosomes. Additional information: Satellites are autosomal translocations; however, they can occur on the Y chromosome.
Hence, option B is correct.
SAT chromosome is used as a marker chromosome.
Note: The appearance of twenty-two of these pairs, known as autosomes, is the same in both sexes. In contrast to females, who have two copies of the X chromosome, males only have one X and one Y chromosome. According to size, there are 22 autosomes.