Ecology Levels of Organization Levels of Organization Ecosystems

Ecology

Levels of Organization

Levels of Organization

Ecosystems

Example of some Local Ecosystems

Population A group of organisms of the same species living in the same area. Examples • The number of White Tail Deer living in Hampton. • The number of people living in New Hampshire

Limits on Population Size • Why don’t population sizes increase forever?

Community All populations in one area interacting Prod ucer s Con sum s r se o c De o p m ers

Community Relationships

Energy Flow

Energy Flow Autotrophs

Energy Flow Types of Heterotrophs

Food Chain The Steps are Called TROPHIC LEVELS

Food Web

Feeding Relationships

Ecological Pyramids

Roughly 10% of the energy is transferred 1 30 1, 100 15, 000 Leaves

Pyramids Continued

What Happens to the 90% that is NOT transferred to the next level?

2 How do plants get their food ? 74 kg soil 73. 943 kg soil In the 17 th Century, A Belgian physician, van Helmont, set up an experiment in which he planted a willow sapling in a weighed amount of soil. The soil was watered but nothing else was added. After 5 years, the tree had gained 74 kg in weight but the soil had lost only 57 g. van Helmont concluded that the tree had made 74 kg of new growth from water alone

3 van Helmont’s experiment was effective in showing that the plant’s food did not come from the soil. But he had overlooked the fact that air was available to the plant as well as water. Could it be that the plant made 174 kg of material from just air and water? This might seem unlikely but we now know that plants do indeed make their food from carbon dioxide from the air and water from the soil.

9 carbon dioxide water sunlight (energy) water

Photosynthesis

Photosynthesis

9 Energy It takes energy to make CO 2 combine with H 2 O This energy comes from sunlight The energy is absorbed and used by a pigment called chlorophyll

Leaf Anatomy

10 Chlorophyll The chlorophyll in the cells is packaged into tiny structures called chloroplasts The next slide shows a diagram of leaf cells with their chloroplasts

Plant Cell

Anatomy of a Leaf

What happens to the glucose? 15 The glucose made by the chloroplast is either (a) used to provide energy for the chemical processes in the cell ( by respiration) (b)turned into sucrose and transported to other parts of the plant or (c) turned into starch and stored in the cell as starch grains In darkness the starch is changed back into glucose and transported out of the cell

23 TO SUM UP Plants combine carbon dioxide from the air, and water from the soil to make glucose. The energy needed for this process comes from sunlight The sunlight is absorbed by chlorophyll contained in the chloroplasts of the leaf. The glucose can be used for energy or to make other substances. To make other substances, the glucose must be combined with other chemical elements such as nitrogen and potassium. These chemical elements are present in the soil

Respiration = use of oxygen to burn food for energy

Respiration Chemical Formula It’s the Reverse of Photosynthesis

REVIEW Animals get their food by eating plants, or other animals Carnivores eat animals Herbivores eat plants Plants make their own food They combine carbon dioxide from the air with water and dissolved salts from the soil Plants do NOT get their food from the soil The process by which plants make food is called PHOTOSYNTHESIS 4

Question 1 For a plant to make glucose it needs (a) CO 2 and H 2 O (b) CO 2, H 2 O and sunlight (c) CO 2, H 2 O, sunlight and chlorophyll (d) CO 2, H 2 O, sunlight, chlorophyll and nitrates 25

26 Question 2 A by-product of photosynthesis is (a) Water vapour (b) Oxygen (c) Carbon dioxide (d) Nitrogen

Question 3 The food made by photosynthesis is stored as the plant in the form of (a) Glucose (b) Sucrose (c) Starch (e) Cytoplasm 29

Cycles of Matter • Unlike the one-way flow of energy, matter is recycled within and between ecosystems. • These cycles are the water cycle, Nutrient Cycle, Carbon Cycle, nitrogen cycle and phosphorus cycle. • These cycles are important so that the matter can be re-used by living things.

Water Cycle

Oxygen/Carbon Cycle

Carbon Cycle

Nitrogen Cycle

The Nitrogen Cycle Nitrogen gas Plants Make Proteins with Nitrates (N 2) Animals Make Proteins by consuming Plant or other organisms Waste Soil Bacteria Nitrite (NO 2) Soil Bacteria Nitrate NO 3 Nitrate (NO 3)

Nitrogen Cycle FOOD contains PROTEIN Nitrogen is in the fish in the form of PROTEIN__ WASTE (NH 3) (NH 4+) NO 3 is absorbed by the plant roots and made into Nitrogen in the waste is in the form of _____________ that can be used in food AMMONIA NH 3 Uneaten food is decomposed into Ammonia (NH 3) by BACTERIA NO 3 is eaten “decomposed by a bac 3 erial called Ammonia is eaten “decomposed” by a bacteria called (NO 2) __NITROBACTER__ into _NITROSOMONAS Nitrite ____NITRATE, into NITRITE, NO 2 NO 3 ___

19 Nitrates are present in the soil, dissolved in water The plants take up nitrates in the soil water The nitrates are conducted through the roots to the stem and then to the leaves In the leaves, the nitrates and glucose are combined to make proteins This process is called assimilation