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ENV CHAPTER 4-1: ECOSYSTEMS, EVERYTHING IS CONNECTED
Everything affects everything elseEcosystem – all the organisms living in an area together with their physical environmentecosystems run into each other – there are no clear boundaries form one to the next An ecosystem needs 5 basic components:1. energy (in most cases from the sun)2. mineral nutrients3. water4. oxygen and CO25. living things Ecosystems have living and nonliving thingsbiotic factors – things that are alive or were alive once – plants, animals, dead things, wasteabiotic factors – nonliving things – air, water, rocks, sand, light, temperature Scientists organize living things into categories (from simplest to most complex):- organism – individual living thing- species – group of living things that are similar and can mate with each other to produce fertile offspring- population – all the members of a species living in the same place at the same time- community – group of species that live in the same place and interact habitat – the place an organism lives. Every habitat has specific characteristics that the organisms that live there need to surviveENV CHAPTER 4-2: EVOLUTION
Organisms become good at living in their particular environment-This happens by natural selectiono Organisms in a population have slightly different traitso some are better than otherso the individuals that survive best and are able to reproduce most pass on their traits to the next generationo therefore it's the unequal survival and reproduction that results form the presence or absence of particular traits. The result = a greater proportion of the organisms in the next generation have the favorable trait. Evolution – the resulting change in genetic characteristics of a population from one generation to the next. Why / how evolution happens:1. organisms produce more offspring than can survive2. the environment is hostile and has limited resources3. organisms differ in traits they have4. some inherited traits give organisms an advantage5. each generation contains proportionately more organisms w/ advantageous traits adaptation – inherited trait that increases an organisms chance of survival and reproduction co-evolution – organisms evolve adaptations to deal w/ other organisms they interact w/ evolution by artificial selection - selective breeding of organisms to have specific traits evolution of resistance – when an organism evolves so that it’s able to tolerate a certain substance that’s supposed to kill it they have a gene that protects them from the substance. it is accidentally selected for by humans.ENV CHAPTER 4-3: THE DIVERSITY OF LIFE
There are 6 kingdoms:The first two kingdoms are composed of bacteria – they are single-celled, have cell walls, no nucleus. 1. archeabacteria – single celled, no nucleus, reproduce by dividing in half, live in harsh places2. eubacteria – single celled, no nucleus, reproduce by dividing in half, are all over the place bacteria play important roles in the environment – breaking things down, making nutrients available to other organisms3. fungi – absorb their food through their body surface, have cell walls, most live on land. Important in breaking things down and recycling nutrients.4. protists – most single-celled, some are multi-celled, most live in water (algae)5. plants – many cells, make their own food by photosynthesis, have cell walls. 3 main groups: lower plants (ferns and mosses)gymnosperms (non-flowering like pines)angiosperms (flowering like crop plants). Most organisms are hugely dependent on flowering plants for food. And angiosperms depend on animals to pollinate and distribute their seeds.6. animals – many cells, no cell walls, ingest their food, live on land and water. Vertebrates (backbone) and invertebrates (no backbone). Tons of different kinds. Insects are the most successful invertebrates – they have a waterproof exoskeleton, are quick, small, can hide easily, reproduce fast, and require little food.
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