Question

Mention the number of chromosomes at each stage. Correlate the life phases of the individual with the stages of the process.

Describe the three types of pollination that can occur in a chasmogamous bisexual flower.

Draw the diagram of a mature pollen grain released at the two celled stage and label four parts in it.

(a) Distinguish between the two cells enclosed in a mature male gametophyte of an angiosperm. (b) Study the diagram given below showing the modes of pollination. Answer the questions that follow. (i) The given diagram shows three methods of pollen transfer in plants. Examine them carefully and write the technical terms used for pollen transfer methods '1', '2' and '3'. (ii) How do the following plants achieve pollination successfully ? (a) Water lily (b) Vallisneria (iii) Write advantages of pollen transfer method '3'.