Download Grade 9 Applied Science – Biology

Grade 9 Applied Science – Biology
Species Interactions
(Textbook Chapter 2.8)
LIMITING FACTORS are factors that can determine which types of organisms AND how many of each
species are able to survive in a certain area or ecosystem.
 Limiting Factors can be either abiotic
(e.g., water, temperature, wind) or biotic
(e.g., types of plants available to eat,
types of animal predators in the area).
 TOLERANCE RANGE is the range of
abiotic conditions within which a species
can survive. As the figure shows, most
organisms cannot live in conditions of
extreme dry and extreme wet. The
Tolerance Range for most species lies in
between the dotted vertical lines
BIOTIC LIMITING FACTORS often determine
how EASILY a species can survive. There are five Biotic Limiting Factors. See Table 2 (Page 56 in your
textbook to complete this RELATIONSHIP chart.
RELATIONSHIP
DEFINITION
EXAMPLE
Competition
Predator – Prey
Mutualism
Commensalism
Parasitism
CARRYING CAPACITY is the limit of the ecosystem. That is, it is the maximum population size of a
species that a given ecosystem can sustain indefinitely. Why?
AFRICAN SAVANNAH
An African savannah includes the following organisms. Examine each organism and determine its
relationship with the other organism of the savannah. For example, a hyena may be a COMPETITOR
with a lion.’;
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Hyena
Impala
Lion
Termite
Wildebeast
Zebra
Cheetah
Tapeworm
Ticks
Hare
Elephant
Wild Dog
Vulture
Rhino
Giraffe
Aardvark
Warthog
Mice
Mongoose
Antelope
Cattle egret
Liver flukes (Flatworms)
Army ants
Red-billed Hornbill
Grasshopper
Red-billed oxpecker