Plants and Ecology - Plants Ecology 19 20 28 What are Plants A plant is a multicellular eukaryote and a photoautotroph An organism that makes its own

Plants and Ecology - Plants Ecology 19 20 28 What are...

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Plants &EcologyChapters 16, 18, 19, 20, 28
What are Plants?A plantisa multicellular eukaryote anda photoautotrophAn organism that makes its own food by using sunlight to convert inorganic materials into organic materials (photosynthesis) for use in cellular functions.
Structural Adaptations of PlantsIn terrestrial habitats, the resources that a photosynthetic organism needs are found in two very different places.Light and carbon dioxide are mainly available in the air.Water and mineral nutrients are found mainly in the soil.The complex bodies of plants are specialized to take advantage of these two environments by havingaerial leaf-bearing organs called shootsand subterranean organs called roots.
Structural Adaptations of PlantsMost plants have mycorrhizae, symbiotic associations of fungi and roots, in which the fungiabsorb water and essential minerals from the soil,provide these materials to the plant, andare nourished by sugars produced by the plant.Mycorrhizae are key adaptations that made it possible for plants to live on land.
Structural Adaptations of PlantsLeaves are the main photosynthetic organs of most plants, utilizingstomata, microscopic pores found on a leaf’s surface, for the exchange of carbon dioxide and oxygen with the atmosphere,vascular tissue, a system of tube-shaped cells that branch throughout the plant, for the transport of vital materials, anda waxy layer coating the leaves and other aerial parts of most plants called the cuticle, for the retention of water.
Structural Adaptations of PlantsTwo types of vascular tissue exist in plants:1. xylemtransports water and minerals from roots to leaves and2. phloem distributes sugarsfrom leaves to the roots andto other nonphotosynthetic parts of the plant.Vascular tissue in plants is also found in the.roots and.shoots.
Reproductive AdaptationsPlants produce their gametes in protective structures called gametangia, which have a jacket of protective cells surrounding a moist chamber where gametes can develop without dehydratingThe zygote develops into an embryo while still contained within the female parent in plants but not in algae
Plant DiversityThe history of the plant kingdom is a story of adaptation to diverse terrestrial habitats.The fossil record chronicles four major periods of plant evolution, which are also evident in the diversity of modern plants.
BryophytesAbout 475 million years ago, plants originated from an algal ancestor giving rise to bryophytes, nonvascular plants without lignified walls,true roots, ortrue leaves.Bryophytes includemosses,liverworts, and hornworts.
Vascular PlantsAbout 425 million years ago, fernsand a few other groups of vascular plants evolvedwith vascular tissue hardened with lignin butwithout seeds.
GymnospermsAbout 360 million years ago, gymnospermsevolved with seedsthat consisted of an embryo packaged

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