Black (stem) rust of wheat is caused by

• Alternaria solani

• Ustilago nuda

• Puccinia graminis

• Xanthomonas oryzae

Why are xylem and phloem called complex tissues?

What is stomatal apparatus? Explain the structure of stomata with a labelled diagram. 

Name the three basic tissue systems in the flowering plants. Give the tissue names under each system.

How is the study of plant anatomy useful to us?

What is periderm? How does periderm formation take place in the dicot stems?

Describe the internal structure of a dorsiventral leaf with the help of labelled diagrams.

Cork cambium forms tissues that form the cork. Do you agree with this statement? Explain. 

A transverse section of stem is stained first with safranin and then with fast green following the usual schedule of double staining for the preparation of a permanent slide. What would be the colour of the stained xylem and phloem?

Cells of this tissue are living and show angular wall thickening. They also provide mechanical support. The tissue is