SME
Grade 9 Science · Problem type
Two species, one food
Use this for “Two protist species grow together in one dish. Which one wins, and why?”
Record and look
10
10
60
50
130
70
170
50
180
20
190
0
Day 0
Day 4
Day 8
Day 12
Day 16
Day 20
per mL
Day 0
Day 4
Day 8
Day 12
Day 16
Day 20
Species A
10
60
130
170
180
190
Species B
10
50
70
50
20
0
Species A
Species B
Species B peaks at 70 per mL, then dies out while species A reaches 190: A competes B out.
Tap a bar at the height you want.
Assumptions
•
Two species that need the same food compete; the one that gets it faster grows, and the other shrinks.
•
Grown apart, each species levels off at its own carrying capacity.
•
When one species dies out in the shared dish, it has been competed out (competitive exclusion).
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