1.What does pollen unit refer to? 2. What is the difference between a monad, tetrad, polyad, and pollinium? 3. What is pollen polarity? 4. What is the difference between an isopolar and heteropolar...

1.What does pollen unit refer to? 2. What is the difference between a monad, tetrad, polyad, and pollinium? 3. What is pollen polarity? 4. What is the difference between an isopolar and heteropolar pollen grain? 5. What is the definition and function of a pollen aperture?

6. What is the difference between a colpus, porus, sulcus, and ulcerus?