Living on Planet Earth THE PLANT KINGDOM PLANTS REPRODUCE THE NATURE OF THRIVING PLANTS © 2010 abcteach.com

Living on Planet Earth

THE PLANT KINGDOM

PLANTS REPRODUCE

THE NATURE OF THRIVING PLANTS

© 2010 abcteach.com

Plant Reproduction

Plants have evolved over hundreds of millions of years from simple water borne algae. They began thriving on land, first in swampy areas, evolving with adaptations to grow on dryer land formations.


Plant ReproductionAll plants have a method of replicating themselves as well as producing genetically diverse offspring with the help of spores or seeds.


spore

seeds in fruit

Plant ReproductionPlant species are much more likely to survive changes in the environment, and to evolve, when two plants having different genetic characteristics produce offspring.


Selfing Methods

Vegetative reproduction is especially common among all plant species. These methods all produce plants that are the same as the originating plant.


Selfing Methods

For example, fragments of water plants can break off, wash downstream, and develop into new whole plants. Most plants can self-produce from above or below ground with runners, tubers, or bulbs.


Selfing MethodsThese young plants will develop a supportive root system enabling them to mature on their own. All of these plants will have the same genetic makeup.


Sexual MethodsPlant species have a greater chance of surviving changes in the environment and evolving when they produce offspring with plants that have different genetic characteristics.


Sexual MethodsAll plants have a sexual method of reproduction that combines the female ovum cells with the male sperm cells. Some plants use spores, while others use seeds. The microscopic male and female parts are combined with the help of water, wind or animals.


Sexual MethodsIf a new predator, disease, or climate change becomes established in the area, some of the new plants, having genetic traits from the male and female parents, might be able to overcome these changes, and save the species from extinction.


SporesSpores are very simple reproductive parts of a plant. Each spore contains the male and female genetic material needed to start a new plant. The spores develop in protective cases usually on the underside of a leaf.

Scientific Illustration


SporesAs the plant matures, it develops and ripens the spores’ cases. When the temperature and humidity is right for the species, the spore case walls pop open sending spores into the air.


1 spore magnified about 2,000 times

hornwort

Spores

They are carried to warm, moist and shaded areas by wind, water or animals. Each spore will grow and fertilize itself. If it lands on or near another plant, it might become fertilized with the swimming sperm spore of the other plant.


SporesUnlike seeds, spores don’t carry a food source with them so animals don’t eat them. This gives spore bearing plants (mosses, liverworts and hornworts) a greater chance of maturing.


SeedsSeeds are developed in a protective casing such as a cone, fruit, nut or flower. Seeds are fertilized with pollen before they leave the parent plant. Each plant species that replicates by seed has its own methods of producing the male and female genetic material needed to start a new plant.


Seeds

Seeds are carried off the plant by gravity, wind, water or animals. When they reach a place good for growth, and the conditions are right, they will start to develop a new plant using the food energy stored in their pod.

Scientific Illustration


SeedsAnimals eat many of these fertilized seeds, and the developing shoots, because they are a rich food source. But animals also carry uneaten seeds to distant locations.


Seeds

The relationships between plants and animals help both plant and animal species expand their territories, broaden their genetic characteristics, and improve their chances of adapting to changes in the environment.


Plants Thrive

All plants need soil, sunlight, water, and carbon dioxide to grow. All species differ in their requirements for warmth, moisture and nutrition.


Plants ThriveWhen the environment meets the needs of the established fertilized spore or developing seed, a new plant will grow and thrive, bringing beauty and life-giving food to many living things on planet Earth.



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Living on Planet Earth THE PLANT KINGDOM PLANTS REPRODUCE THE NATURE OF THRIVING PLANTS © 2010 abcteach.com