How Much Do You Know About Photosynthetic Eukaryotes?

Kingdom of Photosynthetic Eukaryotes: Key Points

• Plants form the kingdom Plantae, historically encompassing all living things that were not animals, and included algae and fungi. Current definitions exclude fungi and some algae.

• Plants obtain energy from sunlight through chloroplasts derived from endosymbiosis with cyanobacteria, and perform photosynthesis using chlorophyll.

• There are about 380,000 known species of plants, with the majority producing seeds. Plants provide a substantial proportion of the world's molecular oxygen and are the basis of most of Earth's ecosystems.

• Plant cells have a large water-filled central vacuole, chloroplasts, and a strong flexible cell wall outside the cell membrane.

• Most plants are multicellular and differentiate into multiple cell types to form tissues and organs with different physiological functions.

• Photosynthesis is the primary mechanism for capturing light energy using chlorophyll in chloroplasts.

• Plants grow in response to physical and biotic factors in their environment, and can tolerate and repair DNA damage caused by physical and biotic stresses.

• Plants reproduce sexually and asexually, with sexual reproduction involving complex lifecycles and alternation of generations.

• Plants use pattern-recognition receptors to recognize pathogens and trigger a protective response.

• Plants have some of the largest genomes among all organisms, with the largest plant genome belonging to wheat.

• Plants are distributed worldwide and form the dominant physical and structural component of many habitats, serving as primary producers in most terrestrial ecosystems.

• Many animals have coevolved with plants, with flowering plants evolving pollination syndromes and various mechanisms of seed dispersal. Many plants have fungi associated with their root systems in a mutualistic symbiosis known as mycorrhiza.The Importance of Plants

• Legumes have Rhizobium nitrogen-fixing bacteria in nodules of their roots, which fix nitrogen from the air for the plant to use.

• Some plants are parasitic and can be extremely harmful to their plant hosts.

• Epiphytes grow on other plants without parasitizing them and can support diverse arboreal ecosystems.

• Some plants are carnivorous and trap small animals to obtain mineral nutrients.

• Competition for shared resources reduces a plant's growth. Shared resources include sunlight, water, and nutrients.

• Humans depend on plants for food, either directly or as feed in animal husbandry. Agriculture includes agronomy for arable crops, horticulture for vegetables and fruit, and forestry for timber.

• Medicinal plants are a primary source of organic compounds, both for their medicinal and physiological effects, and for the industrial synthesis of a vast array of organic chemicals.

• Nonfood products from plants include essential oils, natural dyes, pigments, waxes, resins, tannins, alkaloids, amber, and cork.

• Thousands of plant species are cultivated for their beauty and to provide shade, modify temperatures, reduce wind, abate noise, provide privacy, and reduce soil erosion.

• Plants have been used as model organisms in basic biological research, genetics, and paleobotany.

• Weeds are commercially or aesthetically undesirable plants growing in managed environments and can become invasive, damaging existing ecosystems.

• Many plants produce toxins to protect themselves from herbivores, which can be harmful to humans and livestock.