Question

Which of the following terms describes the normal type of chromosome arrangement where an organism has the correct number of chromosomes?

• A. Monoploidy.
• B. Aneuploidy.
• C. Polyploidy.
• D. Euploidy.

Hint:

Euploidy represents the normal chromosome arrangement, while aneuploidy refers to abnormalities caused by the loss or gain of specific chromosomes.

Answer 1

The Correct Option is D

Step 1: Understanding chromosome arrangements. 
Chromosome arrangement refers to the number and structure of chromosomes within a cell. The normal condition, where an organism has the correct number of chromosomes (a complete set), is termed euploidy. 

Step 2: Explanation of terms. 
Monoploidy (Option A): Refers to cells with a single set of chromosomes (e.g., \(n\)), typically seen in some specialized organisms but not in normal diploid organisms. 

Aneuploidy (Option B): Refers to an abnormal chromosome number due to the gain or loss of specific chromosomes (e.g., trisomy, monosomy). 

Polyploidy (Option C): Refers to organisms with more than two complete sets of chromosomes (e.g., \(3n, 4n\)), common in plants but not normal for humans. 

Euploidy (Option D): Refers to organisms with the correct and complete number of chromosomes in multiples of a basic set (e.g., \(2n\) in diploids), representing the normal state. 

Step 3: Conclusion. 
The term euploidy describes the normal chromosome arrangement in organisms. \[ \therefore \text{The correct answer is: Euploidy.} \]