27. Answer in detail III

 

a. Gymnosperm are naked seed plantclosed seeded plant., because ovule is enclosed by ovaryovule is not enclosed by ovary. Gametophytic and Sporophytic are the two stages of a Gymnosperm's life cycle. The sporophytic generation is the recessivedominant  one that contains the reduced gametophytes. The sporophytic plant body is not differentiateddifferentiated into root, stem and leaf. They have undevelopedwell developed  vascular tissues. In these plants, water is conducted by the tracheidssieve cellof the xylem, and food is conducted by the sieve cell of the phloem.

 

b. The term angiosperms is a combination of two Greek words 'angio' which means closed opened and 'sperma', which means seedfruit.

The habits of the angiosperm plants may be herb, shrubherb, shrub and tree. These are the plants that have well developed vascular tissues Ground tissue called xylem and phloem. Xylem contains vessel, tracheid, xylem parenchyma and xylem fibre sieve tubes, phloem parenchyma, companion cells and phloem fibres. Phloem contains sieve tubes, phloem parenchyma, companion cells and phloem fibresvessel, tracheid, xylem parenchyma and xylem fibre.