Ch 30 notes - Ch 30 Green Plants-green plants dominate...

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Ch 30 Green Plants -green plants dominate terrestrial and freshwater habitats -green plants comprise two major types of organisms: -green algae-important photosynthetic organism in aquatic habitats-lakes, ponds, and other freshwater settings -study as land plants (instead of protists)- 1. They are closest living relative to land plants and form a monophyletic group with them, and 2. The transition from aquatic to terrestrial life occurred when land evolved from green algae -land plants-key photosynthesizers in terrestrial environments -first to thrive with their tissues completely exposed to the air -when evolved, multicellular organisms began to occupy dry terrestrial habitats -fungi grew belowground and helped provide land plants with nutrients from the soil; in return, the plants provided the fungi with sugars and other products of photosynthesis -ecosystem consists of all the organisms in a particular area, along with physical components of the environment such as the atmosphere, precipitation, surface water, sunlight, soil, and nutrients -plants are “ecosystem services”-they add to the quality of the atmosphere, surface water, soil, and other physical components of an ecosystem -plants produce oxygen, build soil, hold soil, hold water, and moderate the locate climate -the sugars and oils that land plants produce by photosynthesis provide the base of the food chain in the vast majority of terrestrial habitats -photosynthetic protists and bacteria are the key to the carbon cycle in the oceans just as green plants are the key to the carbon cycle on the continents (take CO2 from atmosphere and make sugars) -agricultural research began with the initial domestication of crop plants, which occurred independently at several locations around world between 10,000 and 2000 years ago -artificial selection -deliberate manipulation by humans, as in animal and plant breeding, of the genetic composition of a population by allowing only individuals with desirable traits to reproduce -for 100,000 years, wood burning was the primary source of energy used by all humans -first fuel to replace wood in many cases has been coal, which forms from partially decayed plant material that is compacted over time by overlying sediments and hardened into rock -in mid-1800s, people in England, Germany, and the United States began to mine coal deposits that originally formed during the Carboniferous period some 350-275 million years ago weed -a species that is adapted to thrive in habitats where soils have been disturbed annual plant-individuals do not live from year to year but overwinter as seeds perennial -plants that survive from one year to the next - A. thaliana can grow from a seed into a mature, seed-producing plant in just four to six weeks, has just five chromosomes, has a relatively small genome with limited numbers of repetitive sequences, can self-
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This note was uploaded on 10/25/2009 for the course LIFESCI Life scien taught by Professor Lorenz,t.c. during the Fall '09 term at UCLA.

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Ch 30 notes - Ch 30 Green Plants-green plants dominate...

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