Chromosomal Theory Of Inheritance

The correct Option is : 2

Euploidy is the condition of having a complete set of chromosomes, which is essential for normal development and functioning. Aneuploidy, on the other hand, involves the presence of an abnormal number of chromosomes, which can lead to various genetic disorders and developmental issues.

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., ), 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., ), 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., in diploids), representing the normal state.

Step 3: Conclusion.
The term euploidy describes the normal chromosome arrangement in organisms.