Transcript 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).
• Metabolism – all of the chemical reactions in a cell
• Catabolic pathways release energy
• Anabolic pathways use energy
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/VCXa1N5gcM/s1600/Food+is+fuel.jpg
Type of Food and the Energy Provided
http://4.bp.blogspot.com/-uDnnZFxSP40/TZ3GE1UfzAI/AAAAAAAAADs/abhifVvHqiE/s1600/2_Nutrition+training.jpg
Food component
Energy 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
If a hummingbird spends
120 Kcal/hour to collect
nectar, how much energy
must the nectar provide?
Ferret chasing bunny
A Coyote will only chase its prey so far.
http://photographylife.com/wp-content/uploads/2009/12/Coyote-Hunting.jpg
https://www.audubon.org/field-guide/bird/american-goldfinch
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.