Question

endoplasmic reticuli cilia and flagella tube-like structures that are the site of protein and lipid synthesis

Explanation:

• Endoplasmic reticulum: It has a network of tube - like structures. The rough endoplasmic reticulum (with ribosomes) is involved in protein synthesis and the smooth endoplasmic reticulum is involved in lipid synthesis, so it matches the given description.
• Cilia and flagella: These are appendages of the cell. Cilia are short, hair - like structures and flagella are long, whip - like structures. They are mainly responsible for cell movement (e.g., sperm cells use flagella to move, and cilia in the respiratory tract move mucus and trapped particles).

Answer:

For "endoplasmic reticulum", the matching description is "tube - like structures that are the site of protein and lipid synthesis".
For "cilia and flagella", their function is related to cell movement (they are hair - like or whip - like structures that help in cell locomotion or movement of substances across the cell surface).