SmithLifeScience                                             Name __________________ Period _____

SciWolf.bmp (49322 bytes) Reading Study Guide 21-3 Interactions Among Living Things
Reading Study Guide 21-4 Changes in Communities
Pages 722-733

Section 3 Interactions Among Living Things (p.722-729)

Adapting to the Environment p.723



_____  1.  Natural Selection A. behaviors and physical characteristics that allow organisms to live successfully in their environment
_____  2.  Adaptations B. role of an organism in its habitat; or how it makes it living
_____  3.  Niche C. a  process where a characteristic that makes an individual better suited to its environment that may become common in that species

Saguaro Cactus Community p.723
4.-5. Name 2 birds that live in the Saguaro community. __________________________

6-7. Name 2 poisonous reptiles that live in the Saguaro cactus community. __________________

Competition p.724
8-10. There are 3 major types of interactions among organisms. Name them.


11. The warblers in Figure 13 on page 724 live in the same spruce forest.
    They all eat insects that live in the spruce trees.
    Why aren't the warblers in competition for food?

Predation p.725-727

12. An interaction in which one organism kills and eats another is called _________________.

13. The organism that does the killing is called the ___________________. 

14. The organism that is killed is called the _______________.

As the population of one species changes, the population of another species that depends on the first species for survival may change as well.  Use the graph below to answer questions #15-19.

SciWolfMooseGraph.bmp (307638 bytes)

15. How did the Isle Royale wolf population change between 1977 and 1980?

16. How did the moose population change during that same period?

17. How did the wolf population change between 1986 and 1988?

18. How did the moose population change during that same period?

19. What is one reason the moose population dropped between 1974 and 1981?

Predator Adaptations p.726

20.-29. List the adaptations that help these predators catch and kill their prey.


                        Adaptation                                          Prey            
Horseshoe Bat    


Prey Adaptations p.726

Explain how each of these animals displays an adaptation to help them from becoming prey.


                        Defense Strategy                            
Antelope 30.
Caterpillar 31.
Pangolin 32.
Walking leaf insect 33.
Grasshopper 34.

Symbiosis p.728-729

Symbiosis is a close relationship between two species that benefits at least one of them.

Complete the chart that compares the 3 types of symbiosis.

Types of Symbiotic Relationships

Type of Relationship

How Species Are Affected               

Mutualism 35.
36. One species benefits; the other species is unharmed
37. One species benefits; the other species is harmed

39-42. Yellow-billed oxpeckers eat ticks that feed on the hippo's blood.
      How does the bird benefit? ______________________
      How does the hippo benefit.______________________
      What animal is the parasite? __________________
      What animal is the host? ___________________

Identify each of the following as: Mutualism, Commensalism, Parasitism

43. The red-tailed hawk builds a nest in the saguaro cactus.
      The cactus is not harmed.

       This is an example of ______________________

44. Stinging ants nest in acacia trees.
     The tree provides the ants' only food.
     The ants attack other animals that approach the tree.
     The ants clear competing plants away from the tree.

     This is an example of _______________________

45. Long-eared bats eat pollen.
      The cactus's pollen is carried to another plant by the bat's nose.
      This is an example of _______________________

46. Microscopic mites, Demodex folliculorum, live in your eyelashes.
      The mites eat your dead skin
      This is an example of _______________________

47. A remora fish attaches itself to the underside of a shark.
      The remora eats leftovers from the shark's meals.
      The shark is not harmed.

      This is an example of _______________________

48. A vampire bat drinks the blood of horses.
      The horses can become weak from loss of blood.

      This is an example of _______________________

49. Bacteria live in the stomachs of cows.
      The bacteria get food and a place to live.
      The cow gets help in digesting its food.

      This is an example of ______________________

Section 4 Changes in Communities (p.730-733)

50. What is succession?

51-54.. Name the 4 stages of Primary Succession


55-58.  Name the 4 stages of Secondary Succession


59. Secondary Succession occurs in a place where an _____________ currently exists.