1 / 7

B3 Life on Earth

B3 Life on Earth. Lesson 3 : Chains of Life. Objectives. MUST describe how energy passes out of food chains SHOULD calculate the efficiency of energy transfer in food chains. Key Words. You need to be able to define the following: Photosynthesis Efficiency Decomposer

minty
Download Presentation

B3 Life on Earth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. B3 Life on Earth Lesson 3: Chains of Life

  2. Objectives • MUST describe how energy passes out of food chains • SHOULD calculate the efficiency of energy transfer in food chains

  3. Key Words • You need to be able to define the following: • Photosynthesis • Efficiency • Decomposer • Detritivore (Higher tier only)

  4. Textbook Answers 1) It is the start of nearly all food chains on Earth; it provides the energy to these food chains. 2) Photosynthesis 3) Carbon dioxide and water react, using energy from sunlight, to form oxygen and glucose. 4) Some energy passes out of food chains as heat, to power movement or as indigestible parts. 5) Percentage efficiency = (10 / 80) × 100% = 12.5% 6) Cold-blooded animals have a higher efficiency of energy transfer because no energy passes out of the food chain in keeping them warm. 7) They are broken down by decomposers such as bacteria and fungi, aided by detritivores, who make the work of the decomposers easier by breaking the dead organism down into smaller pieces.

  5. Worksheet Answers Activity 1 (Low demand) 1) energy from Sun carbon dioxide + water  glucose + oxygen 2) Photosynthesis, carbon, water, glucose, glucose, eating Activity 2 (Standard demand) 1) a) 10%; b) 4%; c) 25% 2) The snail is cold-blooded so no energy is transferred to heat to keep the snail warm. The cow has to keep itself warm and move about, and also many parts of the cow such as the hair, horns and hooves are indigestible and not available to the next level of the food chain; this reduces percentage efficiency. The maize plant is low down the food chain and most parts of the plant are edible; thus the percentage efficiency is higher.

  6. Worksheet Answers Activity 3 (High demand) 1) Honey fungus breaks down dead wood; a tree with honey fungus is likely to have a proportion of dead wood in it; this can be dangerous because it can cause branches to fall or the tree to tilt or fall over; this could cause injury to someone in a public place. 2) After detritivores have broken the dead matter into smaller pieces, there is a larger surface area for the decomposers to act on; this means they will be able to break down the dead matter more quickly.

More Related