Animal cells lack:

**The reasoning** Animal cells and plant cells share many structures, but there's one key difference: **cell walls**. Think of it like houses: both Nigerian and European homes have roofs, windows, and rooms (nucleus, cytoplasm, mitochondria) — these are essentials for living. But the **cell wall** is like a thick outer fence made of bricks that only surrounds plant cells. It's rigid and made of cellulose, giving plants their firm structure (why trees stand tall!). Animal cells only have a **cell membrane** — a thin, flexible boundary (like a soft curtain, not a wall). This flexibility lets animal cells move and change shape, which our muscles, blood cells, and skin need to do. **Why the wrong options tempt you** - **A, C, D**: These are found in *both* plant and animal cells. The nucleus controls the cell, cytoplasm is the jelly-like filling, and mitochondria produce energy. Every living cell needs these basics — don't confuse "animal" with "missing important parts." **Quick takeaway** **"Both have organelles; only plants have walls — animals stay flexible."** Remember: cell *wall* = plant exclusive; cell *membrane* = everyone has it.