Question

Among animals and humans the natural process by which clones are generated

• A. Monozygotic twins
• B. Dizygotic twins
• C. Double fertilized eggs
• D. Dedifferentiation

Hint:

Natural Cloning: Monozygotic twins = 100% genetically identical natural clones (single zygote split). Dizygotic twins = Fraternal (two separate zygotes).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Natural mammalian cloning occurs via embryonic splitting of a single fertilized zygote producing genetically identical offspring.

Step 2: Detailed Explanation:
Biological cloning mechanisms:
1. Monozygotic (Identical) Twins: Arise from the spontaneous splitting of a single fertilized zygote or early blastocyst into two distinct embryos. Because they originate from the exact same single sperm and ovum, monozygotic twins possess 100% identical nuclear genomes and represent natural clones.
2. Dizygotic (Fraternal) Twins: Arise from two separate eggs fertilized by two different sperm (genetically no more similar than regular siblings, sharing $\approx 50\%$ of genes).

Step 3: Final Answer:
Hence, natural clones are generated through Monozygotic twins, corresponding to option (A).