1 What is the function of the plant cell wall? 2 What is the difference between protoplasm and cytoplasm? 3 What is the function of cell nucleus? How does it perform its function? 4 What are plasmodesmata? What is their importance to living plant cells? 5 What are the differences and similarities between plant and animal cells? 6 How the parenchyma, collenchyma, and sclerenchyma distinguished from one another? 7 What types of substances do secretory cells secrete?