What is this?
You may be surprised that this is a picture of plants. They look a little like stones. In fact, these plants are often called "living stones." Organisms don't need to have big green leaves to be considered plants. What do you think distinguishes plants from other organisms?
What are Plants?
Plants have adapted to a variety of environments, from the desert to the tropical rain forest to lakes and oceans. In each environment, plants have become crucial to supporting animal life. Plants are the food that animals eat. Plants also provide places for animals, such as insects and birds, to live. From tiny mosses to gorgeous rose bushes to extremely large redwood trees (Figure below), the organisms in this kingdom, Kingdom Plantae, have three main features. They are all:
Recall that eukaryotic organisms also include animals, protists, and fungi. Eukaryotes have cells with nuclei that contain DNA and membrane-bound organelles, such as mitochondria. Photosynthesis is the process by which plants capture the energy of sunlight and use carbon dioxide from the air (and water) to make their own food, the carbohydrate glucose. Plants have chloroplasts, the organelle of photosynthesis, and are known as producers and autotrophs. Other organisms are heterotrophic consumers, meaning they must obtain their nutrients from another organism. Lastly, plants must be multicellular, composed of more than one cell. There are no single-celled plants. Recall that some protists are eukaryotic and photosynthetic but are not considered plants because they are mostly unicellular.
There is great diversity in the plant kingdom, from tiny mosses to huge trees.
- autotroph: Organism that produces complex organic compounds from simple inorganic molecules using a source of energy such as sunlight.
- eukaryotic: Having cells that contain a nucleus and membrane-bound organelles.
- photosynthesis: Process of using the sun's energy to make "food" in the form of glucose.
- producer: Organism that produces food, such as glucose, for itself and other organisms.
- Plants are multicellular and eukaryotic, meaning their cells have a nucleus and membrane-bound organelles.
- Plants perform photosynthesis, the process by which plants capture the energy of sunlight and use carbon dioxide from the air to make their own food.
Use the resource below to answer the questions that follow.
- Plant Kingdom at http://www.youtube.com/watch?v=EHgmNzl6yu0 (4:58)
(Note: this resource includes all algae under Plantae. Scientists have changed this classification because of fundamental differences in how different types of algae do things, like what kind of pigments (e.g. chlorophyll) they use for photosynthesis and how they store energy. Green algae are still in the Kingdom Plantae, but brown algae have their own kingdom (Chromista), and red algae are in the catch all kingdom, Protista.
- What use have humans (Homo sapien) found for Spirulina? To what group of plants does Spirulina belong?
- What group of plant requires water to complete it's life cycle?
- How do the rhizoids of liverworts differ from those of mosses?
- Which group of plants are fruit bearing?
- How are the life cycles of Pteridophytes and Bryophytes similar? How do they differ from other groups of plants?
- If a fern is a plant, then what are three characteristics you know to be true about ferns?
- Mushrooms gain their energy from decomposing dead organisms. Explain why a mushroom is not a plant.