What is the one-word substitute for: "A condition in which an organism has only one copy of a particular chromosome, instead of the usual two"?
Show answer & explanation
Correct answer: A
Explanation
Correct Answer
Monosomy
Explanation
To find the correct one-word substitute, break down the biological definitions of the provided terms:
Monosomy: Derived from the prefix mono- (meaning "one"). It specifically describes a form of aneuploidy where an organism lacks one chromosome of a normal pair, leaving it with only one copy instead of two (e.g., Turner syndrome, 45,X).
Trisomy: Means having three copies of a particular chromosome instead of two (e.g., Down syndrome, Trisomy 21).
Polyploidy: A condition in which an organism possesses more than two complete sets of chromosomes (e.g., triploid or tetraploid), common in plants.
Aneuploidy: A broad, umbrella term for any condition where the chromosome number is abnormal (having extra or missing chromosomes). Monosomy and trisomy are both specific types of aneuploidy.
Key Points
Root Word Breakdown: Mono- (One) + -somy (Chromosomes).
Exam Shortcut: The question specifies exactly "one copy," making the prefix mono- in Monosomy the instant giveaway.