Biology honors: Period 8 By: Daymis Rosa Maria Escobar

What are ginkgoes? Ginkgoes were very abundant in the Jurassic hot and wet climate. Ginkgoes look very much like flowering plants, but they are gymnosperms (naked seeds). During the Jurassic period, there were many closely related species. The only one that has survived to modern times is the species they call the Maidenhair tree which is also known as the Ginko Biloba tree. Ginkgo is a genus of highly unusual non-flowering plants with one extant species, G. Biloba, which is regarded as a living fossil.

Kingdom: Plantae Division: Ginkgophyta Class: Ginkgoopsida Order: Ginkgoales Family: Ginkgoaceae Genus: Ginkgo L. Species: Ginkgo Biloba L Classification

Sexual Reproduction When a pollen grain comes in contact with the gynostrobilus, it grows a pollen tube. This tube enters the female cone until it contacts an egg, then shoots a sperm cell to fertilize the egg. The female egg must be fertilized by the male sperm in order to create an embryo. Ginkgo plants are either male or female for their entire lives. In order for a ginkgo tree to produce a fertilized seed, the sperm from the male pollen must fertilize the ovules (eggs) of the female plant. Sperm are stored in pollen tubes that are produced on tiny pollen "cones" that develop on male ginkgo trees. Eggs are found within seeds that resemble pale colored cherries in appearance at maturity on female ginkgo trees.

The Process The male ginkgo plant produces Sporophylls, which are the stalks that produce the pollen tubes containing two sperm cells. When the ginkgo tree releases its pollen, these tubes become airborne and are transferred to female trees on the wind. The sperm cells themselves are not directly transferred from the pollen to the eggs. These cells are motile and are released from the pollen tube to complete the journey on their own. When the two sperm reach the ovule, one will fertilize the seed within. The seed has a fleshy outer shell that resembles a fruit which will swell as it develops. This fleshy seed has a bad smell due to the butyric acid content (the same smelly and disgusting, chemical that is found in soured butter and cheese, body odor and vomit). This smell helps protect the plant from any hungry predators that are around. Note: this process only happens on the first weeks of growth of the plant once it becomes an adult the plant will loose the odor and continue reproducing and growing

Life of a Ginkgo These plants, or trees grow from seeds with a high starch content and a pigmented outer layer called the sarcotesta. This fleshy layer attracts birds and mammals and encourages them to consume and disperse the seed. Only female ginkgo trees produce seeds, which have a strong odor, making female trees undesirable as landscaping plants. Young ginkgoes are slow growers, They can take up to 20 years to reach sexual maturity. Ginkgoes cannot produce pollen or fruit until this age.

Uses The Ginkgo trees are not only trees, but they are used around the world to treat sicknesses, such as dementia and Alzheimer's. The way it helped treat dementia was by it improving blood flow to the brain. The way it treats Alzheimer's is by protecting the nerve cells that are damaged in the Alzheimer's disease.

Examples of what it can be used for… Improvement in thinking, learning, and memory (cognitive function) Improvement in activities of daily living Improvement in social behavior Fewer feelings of depression Based on research and studies scientist have found that people with Alzhimers, that consume Ginkgo Biloba, will have an improvement on these characteristics

Side Effects Ginkgo Biloba helps control and speed up the blood flow of the human body it contains vitamins 1,2, and A which help in keeping the body stable and strong. But too much consumption of Ginkgo Biloba can result in heart attacks, and a greater probability of loosing memory faster.

Did you know.. This living fossil is sacred to many of the Chinese population, this plant has been worship across china, used in temples at homes and even in hospitals. They honor the plant because 100 years ago a soldier from the Chinese army was diagnosed with Alzheimer's, they looked until they finally found a cure which was the Ginkgo Biloba tree from that day on, tress of these kinds are seen as gods, and are probably the oldest species of trees still standing today. Ginkgo Biloba trees are protected by the Chinese government against any harm.

Examples