Step 1: Understanding the Concept:
This question tests knowledge of functions of cell organelles.
Step 2: Detailed Explanation:
Statement I:
Ribosomes are the sites of protein synthesis in cells.
They translate mRNA into amino acid sequences.
They can be free in the cytoplasm or attached to the endoplasmic reticulum.
This statement is true.
Statement II:
Mitochondria are the energy houses of the cell.
They produce ATP through cellular respiration.
They have their own DNA and are double-membrane organelles.
This statement is true.
Step 3: Final Answer:
Thus, both statements are true.
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