Standard 1: Ecology

1. Objective 1: Summarize how organisms interact with one another and their environment.

A. Arrange components of a food chain according to energy flow

B. Compare the quantity of energy in the steps of an energy pyramid.

C. Describe strategies used by organisms to balance the energy expended to obtain food to the energy gained from the food (e.g., migration to areas of seasonal abundance, switching types of prey based upon availability, Hibernation or dormancy).

D. Compare the relative energy output expended by an organism in obtaining food to the energy gained from the food (e.g., hummingbird – energy expended hovering at a flower compared to the amount of energy gained from the nectar, coyote – chasing the mice to the energy gained from catching one, energy expended in the migration of birds to a location with seasonal abundance compared to energy gained by staying in a cold climate with limited food).

Organisms need to get enough Food• Metabolism – all of the chemical reactions in a cell• Catabolic pathways release energy• Anabolic pathways use energy

Energy Expended to Obtain Food

In order for organisms to have enough energy for cellular function.

They food they consume must contain more energy than is used to obtain and consume the food.

http://1.bp.blogspot.com/-ZGP9EI-7RBA/UXO3istVA_I/AAAAAAAAQn8/VCX-a1N5gcM/s1600/Food+is+fuel.jpg

http://4.bp.blogspot.com/-uDnnZFxSP40/TZ3GE1UfzAI/AAAAAAAAADs/abhifVvHqiE/s1600/2_Nutrition+training.jpg

Type of Food and the Energy Provided

Energy Gained from Food

Food componentEnergy density

kJ/g kcal/g

Fat 37 9

Ethanol (drinking alcohol) 29 7

Proteins 17 4

Carbohydrates 17 4

Organic acids 13 3

Polyols (sugar alcohols, sweeteners)

10 2.4

Fiber 8 2

https://en.wikipedia.org/wiki/Food_energy

https://numberneededtotreat.files.wordpress.com/2010/07/ed3.png

Hummingbird Hovering

If a hummingbird spends 120 Kcal/hour to collect nectar, how much energy must the nectar provide?

Coyote Chasing Mice

A Coyote will only chase its prey so far.

Ferret chasing bunny

http://photographylife.com/wp-content/uploads/2009/12/Coyote-Hunting.jpg

Bird Migration

https://www.audubon.org/field-guide/bird/american-goldfinch

Obesity

http://watifhealth.com/6-ways-to-prevent-obesity/

1. If it took the same amount of energy to chase a mouse as it did to chase a rat, which do you think a cat would choose to chase? Why?

2. What is an example of a strategy used to balance energy used to obtain food with energy gained from the food (other than migration and hibernation)?

Organisms must expend less energy to obtain food than energy gained by that food.