This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Types of Genetic Disorders, Subject name: Pediatrics
Which is the longest chromosome? 
Select and explain. 
A. Chromosome 1, B. Chromosome 21, C. Chromosome 14, D. Chromosome X
A: Chromosome 1
Answer: A: Chromosome 1 
Explanation: Chromosome 1 is the longest chromosome. In a karyotype, chromosomes- arranged according to their length and banding features. Chromosomes 1 to 22 are arranged according to their length, in the descending order. Chromosome X is longer than the Y Chromosome.