GYMNOSPERMS

GYMNO (NAKED) SPERMA(SEEDS)

• It includes medium sized and tall trees as well as shrubs.Sequoia (giant red wood tree) is one of the tallest tree species.
• Leaves in gymnospems are well adapted to withstand extremes of temperature, humidity and wind. Thick cuticle, sunken stomata and needle like leaves reduce the surface area.
• These are the plants in which ovules are not enclosed by any ovary wall.
• After fertilisation seeds remain exposed and therefore these plants are called naked seeded plants
• Gymnosperms produce microspores and megaspores which are produced in microsporangia and megasporangia borne on sporophylls
• The sporophylls are arranged spirally on axis to form male and female cones respectively.These may be borne on the dsame tree (Pinus) or on different trees( Cycads)



mature female cone pinus

• After fertilisation zygote develops into embryo and ovules develop into seeds.



cycad female cone



cycas male cone

• Gametophyte does not have an independent existence. They remain within the sporangia retained on the sporophyte.



second year male cone pinus

• Children you can watch these videos on youtube for purpose of clarity 

www.youtube.com

Nature Notes Female and Male Pine Cones - Longleaf Pine.

Male or Female Sago, How to tell the difference