Identify an organelle found both in eukaryotic as well as prokaryotic.

The correct option is Ribosomes.

To understand why ribosomes are found in both eukaryotic and prokaryotic cells, we can analyze the structural differences and cellular requirements of these two cell types:

1. Prokaryotes vs. Eukaryotes: Eukaryotic cells are defined by the presence of a membrane-bound nucleus and membrane-bound organelles (such as mitochondria, lysosomes, and endosomes). Prokaryotic cells lack a nucleus and any membrane-bound organelles.

2. Nature of Ribosomes: Ribosomes are non-membrane-bound structures composed of ribosomal RNA (rRNA) and proteins. Because they do not possess a lipid membrane, they do not violate the structural definition of prokaryotes.

3. Essential Function: Ribosomes are the cellular machinery responsible for protein synthesis (translating messenger RNA into polypeptide chains). Since all living cells—both prokaryotic and eukaryotic—require proteins to carry out basic life processes and structural functions, ribosomes are universally present in both domains of life.

4. Other Options:
- Mitochondria: Double-membrane-bound organelles responsible for aerobic respiration, found only in eukaryotic cells.
- Lysosomes: Single-membrane-bound organelles containing digestive enzymes, found only in eukaryotic cells.
- Endosomes: Membrane-bound vesicles involved in sorting and routing materials internalized via endocytosis, found only in eukaryotic cells.