food: an ecosystem perspective biology 101 laboratory biology and society laboratory exercise 10
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Food: An Ecosystem Perspective
Food: An Ecosystem Perspective
Biology 101 Laboratory
Biology and Society
Laboratory Exercise 10
Objectives
When you have completed this lab, you will be able to:
Identify a wide range of plant foods that are eaten worldwide
Understand the geographic origin of major food species
Understand the biodiversity available in our crop plants
What food plant did you bring in?
Where does it come from?
Where is it grown now?
Any interesting uses besides food?
HW Review:
The Plants We Eat
potatoescassavasweet potatoyam
soybeanspeanuts, groundnutsbeanspeas
grassesgrasses
roots &tubersroots &tubers
legumeslegumes
ricewheatcorn, maizebarleyoatsryemilletsorghum
Geographic Origin
Food species have been spread by humans for thousands of years
Often crops that are minor in their native range become major crops in different locations
Class Exercise: Geographic Origin
Common processed foods labels:
• What species are on the ingredients list?
• Online, find natural origin of each species/ingredient
• How many different species; from how many continents?
Crop Biodiversity
Many varieties selected from crop species
Selection by humans can result in varieties of the same plant that look like separate species
Species or Variety?
Different name but same species:• Broccoli • Collard greens• Cabbage
All are Brassica oleracea
Species or Variety?
Same name but different species:• Cabbage: Brassica oleracea• Chinese Cabbage: Brassica
campestris • Mustard Cabbage: Brassica juncea
CropWheatRiceCornSorghumSoybeansPotatoesCassavaTomatoes
The Crop Gene Bank
Accessions850,000420,000262,000168,500176,000
31,00028,00077,500
Percent9090958070
80-903590
HW: Biodiversity in Our Diet
Go to a food store selling fresh produce:• Survey the fruits and vegetables• Identify the species in which you can
find the most varieties in this store• Choose 5 species with the most
varieties• Report the total number of “varieties” in
each of these high-diversity species and list each variety
HintsOnly look at the five species with the highest diversity
Note that some species come in very different (and unexpected) forms [Cabbage, broccoli, Brussels sprouts, etc.; all the kinds of lettuce]
The whole idea is for you to look critically at the entire produce section, not just at things you usually buy
Fig. 2. The abundance of fishes decreases as the populations of humans increase. This indicates that humans adversely affect the fish populations, probably by overfishing. The human populations are represented as per km2 of reef.
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