Question

1. Be able to recognize specimens of Gymnosperms and Angiosperms

2. Be able to identify the male and female gametophytes in the gymnosperm cones

3. Be able to label the basic parts of the alternation of generations of these groups

4. Within angiosperms, know the differences between monocots and dicots

5. Be able to identify the parts of the flower

6. Understand the process of double fertilization, AND the difference between pollination and fertilization

Answer 1

1.Recognize specimens of Gymnosperms and Angiosperms-

Kingdom plantae is divided in to two sub-kingdoms

1) Cryptogamae - The members of cryptogamae are spore prouducing plants and they do not prouduce seeds and flowers.It includes Algae, Bryophytes and Pteridophytes.

2) Phanerogamae - The members of phanerogamae are called as seed plants.It include Gymnosperms and Angiosperms.

Angiosperms - Angiosperms are flowering plants and their seeds are enclosed in the ovary.Flower is the main reprouductive organ of the angiosperms.There is greater variation in the flowers of angiosperms.Flower has essential whorls like Androecium ( microsporophylls ) and Gynoecium ( megasporophylls ), and some accessory whorls like sepals and petals . This all parts are arranged together to form complete flower. Reprouduction by pollination is the important character of angiosperms.Pollination is the transfer of pollen grains from anther to stigma.Double fertilization is the procress that is only found in the Angiosperms.In double fertilization one male gamate fuses with egg and another male gamate fuses with secondary nucleus.

Gymnosperms - Gymnosperms are flowerless plants and their seeds are naked on surface of leaves.Seeds of gymnosperms are not enclosed in ovary.The seeds of gymnosperms are often called as cones.The stem of gymnosperm is mostly soild erect and cylindrical.They are vascular plants having xylem and phloem.Xylem is present with tracheids and phloem is with sieve cells.

The main difference between Angiosperms and Gymnosperms is the presence and absence of flower. In Angiosperm seeds are enclosed in ovary and in Gymnosperm seeds are naked. By considering this simple characters we can recognize specimens of Angiosperms and Gymnosperms.

2.Male and female gametophytes in gymnosperm cones.

Gymnosperms having naked seeds and they belongs to sub-kingdom Embyophyta and it includes Conifers,Cycads and Ginkgoes.Gymnosperms are heterosporous. Male and female microspores are borne on seperate cones.Gymnosperms have male and female cone. Female cone is larger than male cone.Male cone prouduces haploid microspores and that gives rice to male gametophyte. Female cone prouduces megaspores and called female gametophyte.Male cones lives for few weeks and female cones live for several years.Female cones always grow at upper region and male cones grow at lower region.By considering this difference between male and female cone we can identify male and female gametophyte in Gymnosperms.