Gymnosperms lack the bright, showy flowers and fruit-covered seeds of angiosperms. Gymnosperm literally means “naked seed,” and they are more primitive plants than angiosperms are. Gymnosperms evolved about 300 million years ago.Continue Reading
Because gymnosperms do not produce showy flowers, they do not attract insects, birds and mammals that help with pollination. This means that all gymnosperms are wind-pollinated, and most broadcast a very high amount of reproductive cells into the air.
Because gymnosperms do not produce fruit, they do not depend on animals to eat the fruit and carry the seeds away for dispersal. Accordingly, many gymnosperms have seeds that are designed to float on the air or water in order to travel farther away from the parent plant. Some gymnosperms produce cones that contain a large number of seeds. Many cones remain closed to prevent predators from eating the enclosed seeds, and only open when exposed to fire.
Examples of gymnosperms include conifers, such as pine trees, redwood trees, cedar trees and cypress trees. Ginkgo trees are also gymnosperms, as are palm trees and cycads. Angiosperms outnumber the gymnosperms in the modern world, and are represented by such widely varied species as dandelions, potatoes, oak trees, maple trees and cacti.Learn more about Biology
Though angiosperms and gymnosperms are both seed-producing plants of the Embryophyta subkingdom, they share many more differences than similarities. The most significant regards seed development. While angiosperms produce seeds within an enclosure, the seeds of gymnosperms are not enclosed.Full Answer >
Pollen is produced in the stamen in angiosperms and is produced in the microsporangiate cones in gymnosperms. The cones that pollen is produced in are usually referred to as male cones or pollen cones.Full Answer >
Distinguishing characteristics of the phylum Gnetophyta include the presence of both tracheids and vessels in their xylem tissue, a unique fertilization feature in which a tube grows from the eggs to unite with pollen tubes, and being the only division of gymnosperms that undergo double fertilization. Gnetophyta plants include trees, shrubs, or stumpy, turnip-like growth forms with simple leaves.Full Answer >
Lice eggs, also called nits, look like small sesame seeds, and they are attached firmly to the hair. Dead lice eggs stay afixed to the hair and remain in the hair if they're not removed properly.Full Answer >