Multiple Choice
Which of the following describes a situation in which the chromosome number is either 2n + 1 or 2n - 1?
2
views
6. Chromosomal Variation
Chromosomal Mutations: Aneuploidy
Struggling with Genetics?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Of the following chromosomal abnormalities, which type is most likely to be viable in humans?
A
Monosomy 1
B
Monosomy X (Turner syndrome)
C
Trisomy 21 (Down syndrome)
D
Trisomy 18 (Edwards syndrome)
Verified step by step guidance1
Understand the concept of chromosomal abnormalities: these occur when there is a deviation from the normal number or structure of chromosomes, which can affect viability and development.
Recall that monosomy refers to the presence of only one copy of a chromosome instead of the usual two, and trisomy refers to having three copies of a chromosome.
Recognize that monosomy 1 is typically lethal because chromosome 1 is very large and contains many essential genes, so losing one copy is usually not compatible with life.
Know that Monosomy X (Turner syndrome) involves the loss of one X chromosome in females and is one of the few monosomies compatible with life, but it is less common than some trisomies.
Identify that Trisomy 21 (Down syndrome) is the most common viable trisomy in humans, where an extra copy of chromosome 21 is present, leading to a recognizable syndrome with survival into adulthood, unlike Trisomy 18 (Edwards syndrome), which has a much lower survival rate.
Related Videos
Related Practice
Chromosomal Mutations: Aneuploidy practice set
Problem sets built by lead tutorsExpert video explanations