Ecology and evolution Mrs. Jackie

Communities and ecosystem Ecology- the study of relationship between living organisms and between them and the environment Ecosystem- a community and its abiotic (non biological) environment. Population- a group of organisms of the same species living in the same area at the same time and capable of interbreeding. Species- a group of organisms which look alike, can interbreed and produce fertile offspring Community-a group of populations living and interacting with each other in a habitat Habitat- the physical area in which individuals of a certain species can usually be found.

Explain how the biosphere consist of interdependent and interrelated ecosystems Biosphere- total of all area where living things are found, including the deep ocean and the lower part of the atmosphere Biomes- largest subunits of the biosphere

The biosphere Thin layer associated with the surface of the earth. Ranges from the deep sea to a few kilometers up in the atmosphere. Energy enters in the form of sunlight and lost in the form of heat Matter remain in the biosphere so needs to be recycle continuously.

Major terrestrial biomes Page 505 figure 2- define the following terms Tropical forest Savannah Deserts Chaparral Temperate grassland Temperate deciduous forest Taiga tundra

Define autotroph, heterotroph, detrivore and saprotroph. Heterotroph= consumer: an organism which needs to eat other organisms to obtain energy and large organic molecules. Examples are cows and whales. Autotroph= producer: an organism that makes organic molecules from inorganic molecules using light or chemical energy. Examples: algae and grass

Define autotroph, heterotroph, detrivore and saprotroph Saprotroph: an organism that feeds on dead organic matter using extracellular digestion There are specialized detritivores which consume cellulose and nitrogenous waste Example fungi and bacteria Detritivore: organisms which ingest dead organic material. For example large scavengers, earthworms

Abiotic and biotic factors Biotic- factors that results from the activities of organisms. Abiotic-non living part of the ecosystem Climatic factors- temperature, light, water availability Edaphic factors- associated with the soil; texture, pH, temperature, organic content Topographic factors- angle and aspect of a slope

Classwork Answer questions on pages 505 and 506. All questions including the food for tought

Describe what is meant by a food chain giving three examples, each with at least three linkages A food chain is the transfer of the sun´s energy from producers to consumers as organisms feed on one another Examples Seaweedlimpetstarfishseagull Seaweedlimpetcrabseagull Seaweedperiwinklecrabseal Seaweedperiwinkleoctopusseal Oakleavescaterpillarsrobinsparrowhawk Phytoplanktonshrimpsmelt(fish)heron Grassgrasshopperfrograt

Food chain

Define trophic level The level of the food chain at which an organisms if found Producer: grass (not plants this would be to vague) (first trophic level) Primary consumer: grasshopper(second trophic level) Secondary consumer:frog (third trophic level) Tertiary consumer: rat

Define Food web Interconnected pattern of food chains in an area periwinkle octopus seagull Seaweed crab limpet seal starfish

Classwork Do the quick check on page 509 (number one)

Construct a food web containing up t0 10 organisms, given appropriate information Lab work

Light is the initial energy source for almost all communities While materials cycle through the ecosystem energy enters and is used or changed into other forms of energy and leaves the ecosystem again.

Energy Flow When energy is transferred from one trophic level to another, only approximately 10% is used for growth. The rest is used for other metabolic activities and waste Example 100kJ grass10kJ antelope1kJ cheetah -Page 510-511 Read -Quick Checks and food for thought in your notebook

Explain what is meant by a pyramid of numbers and the reasons for its shape Pyramid of numbers- to represent some data about the trophic levels in a certain area Information about the number of organisms in each trophic level each required. The width at each level represents the number of organisms in each level Look at figure 3 page 509 Difficult to draw to scale Inverted pyramid

Explain what is meant by a pyramid of biomass and the reasons for its shape The dry mass of a trophic level needs to be measured or estimated. Involved complete destruction of the organisms involved. Take into account the differences in sizes between the organisms Depends on the size of the year the sample is taken

Explain what is meant by a pyramid of energy and the reasons for its shape Pyramids of energy Will never be inverted Express in energy per unit area per unit time Lowest bar the gross primary production Next bar energy ingested as food by primary consumers and so on. Amount of energy per unit area that flows through the trophic level in a given time period

Energy Flow Answer quick checks on pages 509 (2) 511 (1-3)

Explain that energy can enter and leave an ecosystem, but nutrients must be recycle We constantly received energy from the sun and also constantly radiate out energy in the form of light and heat The Earth does not received nor send out matter on a regular basis meaning that nutrients must be recycle through the ecosystem This process requires energy