Tropism Plants ability to grow towards sunlight Tropism

Tropism Plants ability to grow towards sunlight (Tropism) is an example of: ___________ Vines growing up larger trees in order to get access to sunlight is an example of a _____________ 02/26/07

Label the parts of this food chain § Primary Consumer § Quaternary Consumer § Secondary consumer § Producer § Tertiary Consumer 02/26/07

Label the parts of this food chain 02/26/07

The adult frog represents a type of consumer known as a: a. producer b. carnivore c. parasite d. herbivore 02/26/07

Which statement about the algae and grass is true? a. They are classified as omnivores b. They parasitize the animals that consume them c. They contain the greatest amount of stored energy d. They contain the least amount of stored energy 02/26/07

Ecology How does energy and matter cycle through an ecosystem? Standard Element: SB 4. b Explain the flow of matter and energy through ecosystems by ●Arranging components of a food chain according to energy flow. ●Comparing the quantity of energy in the steps of an energy pyramid. ●Explaining the need for cycling of major nutrients (C, O, H, N, ). ●

Matter and Energy Transfer in an Ecosystem • • Matter (nutrients) are constantly cycled through an ecosystem Energy from the sun enters an ecosystem through the producers. Energy flows from the producers to the primary consumers, to the secondary consumers and to the tertiary consumers and eventually to the decomposers. Energy is either used, transferred or released as heat, but cannot be cycled!

Food chains • A food chain is a simple model that shows how energy flows in 1 direction through an ecosystem. • Food chains always begin with producers • Producers (autotrophs, plants) plants can make their own food using photosynthesis

Food Webs • A food web is a complex model that shows how energy flows in many directions through an ecosystem. • Food webs always begin with producers on the bottom. • Producers (autotrophs, plants)can make their own food using photosynthesis

Food Chains and Webs show: 1. Energy flows from the producers, to the primary consumers, then secondary consumers, then tertiary consumers 2. Arrows always point from prey to predator because it shows where energy is transferred to. 3. Trophic levels or feeding steps: 1 st trophic level-Producers 2 nd trophic level-Primary consumers 3 rd trophic level- Secondary consumers 4 th trophic level- Tertiary consumers

The Ecological Pyramids 1. Energy Pyramid • Shows the decrease of energy at each trophic level. • The total energy transfer up is about 10% ▫ Not all food that is eaten can be digested ▫ Some of the digested food is used as energy and ▫ Some is released as heat

The Ecological pyramids 2. Pyramid of numbers – Shows the number of organisms on each trophic level – Producers will always have the largest population size. 3. Biomass pyramid(living weight) – Shows the mass of organisms on each trophic level – Producers will always have the largest biomass

Work Session Use Pages In Text (READ) ü Cornell Notes

Nutrient Cycles in Ecosystems Nutrients are constantly cycled through an ecosystem in order to maintain homeostasis. 1. Water Cycle: movement of water through an ecosystem A. Evaporation: liquid to gas B. Condensation: water vapor cools and gets packed to form clouds C. Precipitation: rain, snow, sleet, hail D. Transpiration: water released from plants E. Runoff: extra water collected in rivers and streams

Carbon Cycle in Ecosystems Carbon is most commonly found in the form of CO 2 gas in the atmosphere. Carbon released in the atmosphere by… 1. Burning of fossil fuels (Combustion) 2. Cellular respiration 3. Decomposition Carbon is used by… 1. Photosynthesis

Carbon Cycle • Carbon Dioxide (CO 2) is in the atmosphere & ocean • Producers use CO 2 in photosynthesis. • (CO 2 + H 2 O sugar) • Organisms obtain carbon by eating producers or other consumers. • Respiration & decay returns CO 2 to atmosphere

Nitrogen Cycle in Ecosystems • Organisms need nitrogen to make proteins but we cannot use the nitrogen in the air SOOOO…… • We depend on bacteria to fix it for us! • Nitrogen fixation: bacteria living on the roots of plants absorb nitrogen in the atmosphere and convert it to a form that plants can use to make proteins • Denitrification: Bacteria release nitrogen back into the atmosphere

Nitrogen Cycle in Ecosystems • Organisms need nitrogen to make proteins but we cannot use the nitrogen in the air SOOOO…… • We depend on bacteria to fix it for us! • Nitrogen fixation: bacteria living on the roots of plants absorb nitrogen in the atmosphere and convert it to a form that plants can use to make proteins • Denitrification: Bacteria release nitrogen back into the atmosphere • How do we get the nitrogen that we need? We get nitrogen ü by either eating the plants, ü or by eating the consumer that ate the plants

Nitrogen Cycle • Atmospheric nitrogen makes up 78% of air, but it can’t be used directly. • Nitrogen fixation (by bacteria & fungi) changes it “nitrogen” into usable forms.

n Phosphorous Cycle Phosphorous exists in the soil as “inorganic phosphate” n As rocks and sediments gradually wear down, phosphate is released n It is then washed into the waterways where marine organisms use it n Cycling can also occur on the land among the soil and land-dwelling organisms

Cycles Foldable Carbon Cycle Nitrogen Cycle Phosphorus Cycle

Chapter Assessment n n Once you have completed the Cycles Foldable On the back of the foldable write the answer to the questions on page 49.

Closing n Compare Contrast a food chain to a food web Food Chai n Both Food Web

Closing Both Begin with producers All Niches are represented Show the “flow of energy” Food Chain Simple Model 1 direction Food Web Complex model Many directions