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Why do we abbreviate trisomy as n + 1?

Answer 1

Sebastian Alvarado

Here's the reason.

Firstly I would like to throw some light that #n+1# is not an abbreviation of trisomy.

General abbreviation of trisomy is #2n+1#.

#n# is the haploid number of chromosomes at a certain sequence.

Now, it's diploid is #2n#.

These days, diploidy and haploidy are typical chromosomal intermediates.

However, aneuploidy refers to an aberrant chromosomal count.

Some aneuploid conditions are #rarr#

(1). #2n − 1##rarr# monosomy. (because only one copy of same specific chromosome is present).

(2). #n+1# #rarr# disomy. (because two copies of same specific chromosome is present).

(3). #2n + 1##rarr#trisomy. (because three copies of same specific chromosome is present).

(4). #2n − 2# #rarr#nullisomy. (because no copy of a specific chromosome is present).

I hope it's helpful:).

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Answer 2

Cooper Alexander

Trisomy is abbreviated as "n + 1" because it refers to a condition where there is an extra chromosome compared to the normal diploid number (2n). In trisomy, there are three copies of a particular chromosome, which is one more than the usual two copies. So, "n + 1" represents the additional chromosome in trisomy.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.