In which of the following organelle, peptide synthesis takes place?

The correct option is ribosomes.

Step-by-step Explanation:

1. Understanding Peptide Synthesis:
Peptide synthesis is the biological process where amino acids are linked together by peptide bonds to form polypeptide chains, which ultimately fold into functional proteins. In the cell, this process is known as translation.

2. The Role of Ribosomes:
Ribosomes are the cellular organelles (molecular complexes made of RNA and proteins) that serve as the primary site for translation. They bind to messenger RNA (mRNA) and transfer RNA (tRNA) to catalyze the formation of peptide bonds between amino acids in the sequence specified by the mRNA template.

3. Analyzing the Other Options:
- Chromoplasts: These are plastids responsible for the synthesis and storage of pigments (yellow, orange, or red) in flowers and fruits.
- Chloroplasts: These are plastids in plant cells responsible for photosynthesis.
- Mitochondria: These are the double-membraned organelles responsible for generating ATP through cellular respiration. Although mitochondria contain their own ribosomes to synthesize a few of their own proteins, the organelle specialized and defined by the function of peptide synthesis is the ribosome.