Unformatted text preview: Model 2 – Symbiosis
Organism 1 Organism 2 Description of the relationship Dog Flea The flea feeds on blood from the dog. There
is no benefit to the dog and the itching and
bites may lead to infection. Fungus Termite Shark Cattle Algae Parasitism Mutualism Cellulosedigesting
bacteria The bacteria in the gut of the termite
breakdown and feed on some of the
cellulose taken in by the termite. The
termite would be unable to digest cellulose
without these bacteria and they gain an
additional source of nutrition from the
surplus digested cellulose. Remora The Remora fish swim alongside the shark
and take scraps of food that the shark drops
during feeding. The shark does not eat the
Remora and appears unaffected by its
presence. Commensalism The cattle egret follows herds of cattle and
eats the insects that the cattle stir up as they
move through the grassland. The cattle
appear to be unaffected by the egrets. Commensalism Cattle egret Human The photosynthetic algae provide food for
the fungus, which in turn provides a suitable
living environment for the algae. Symbiotic
Relationship Tapeworm The tapeworm lives in the small intestines
where it feeds and grows, robbing the
human of essential nutrients. Mutualism Parasitism 9. Refer to the information given in Model 2.
a. In the dog and flea relationship, is there a benefit for one of the organisms or for both? Only
the flea benefits because it gets food and can get the dog infected. b. Is either the dog or the flea harmed by this relationship? The dog is harmed because it gets some blood taken out of it and could be infected.
c. Which other relationship in Model 2 is similar to that between the dog and flea? The human and the tape worm because it feeds in the small intestines and steals the
nutrients and could make the person really sick and or infected too. Ecological Relationships 3 10. Refer to the fungus and algae relationship in Model 2.
a. Is there a benefit for one of the organisms or for both? ngus and algae get an benefit because the fungus gets food from the algae which turns into a
suitable envirment for the algae.
b. Is either the fungus or the algae harmed by this relationship? The fungus and the algae is not harmed in this. c. Which other relationship in Model 2 is similar to that between the fungus and the algae? The termite and the cellulose digesting bacteria, when the termite eats, the cellulose digesting bacteria
eats food the termite gets and takes out the bad bacteria for the termite and helps it.
11. Refer to the shark and remora relationship in Model 2. a. In the shark and remora relationship, is there a benefit for one of the organisms or for both? There is a benefit for the remora because it eats the sharks left over food and the shark
does not benefit or it does not harm the shark either.
b. Is either the shark or the remora harmed by this relationship? No shark or remora is harmed
c. Which other relationship in Model 2 is similar to that between the shark and the remora? gret because the cattle egret just eat the insects around the cattle and the insects
harm the cattle so the cattle does not help or benefit from it. Read This!
Symbiotic relationships are identified by how they affect the organisms involved. The three types of symbiotic relationships are listed below.
• Mutualism: Both organisms benefit from the relationship.
• Parasitism: One organism benefits and the other is harmed.
• Commensalism: One organism benefits and there is no effect on the other.
12. Using the information from the Read This! box, label each of the relationships in Model 2 as
mutualism, parasitism or commensalism.
13. With your group, choose one of the organism pairs from Model 2 and justify why you categorized the relationship as you did. 4 POGIL™ Activities for High School Biology Model 3 – Inter- and Intra-specific Competition
Graph A Graph B
P. aurelia and P. caudatum grown together
Relative Population Size Relative Population Size P. aurelia and P. caudatum grown separately P. aurelia
P. coudatum P. aurelia P. coudatum
0 20 Number of Days 0 Number of Days 20 Graph C
Rate of growth of R. tigrina tadpoles in populations of different sizes.
1.0 Mean Body Mass (g) 0.8 Minimum mass needed
to occur. 0.6 5 individuals 0.4 40 individuals
0.2 60 individuals
0 1 2 3 4 5 6 7 8 9 10 Time (weeks) 14. What are the names of the species in graphs A and B in Model 3? aurelia and caudatum 15. Which graph shows competition between two different species? graph A 16. Which graph in Model 3 shows population growth for only one species? graph B 17. What is the difference between the growing conditions in graph A and graph B? That Graph A aurelia and caudatum was very close in size but in graph B aurelia was in a huge lead by size of caudatum. Ecological Relationships 5 18. P. caudatum and P. aurelia are both species of Paramecium, a microscopic protozoan. P. caudatum
is the larger of the two species. When grown separately, which of the two species reaches a larger
relative population size after 20 days? Aurelia is bigger in size.
19. When grown separately is there a substantial difference in the relative population size of the two
types of paramecia after 20 days? Yes, because of the huge difference in sizeing.
20. Compare graphs A and B in Model 3.
a. Which population of species of Paramecium is more affected when the two species are grown
together? aurelia is more affected b. Considering that P. caudatum is 50% larger in size than P. aurelia, develop a hypothesis with
your group to explain why interspecific competition has an effect on the relative population
size of P. caudatum. 21. In a grammatically correct sentence, define interspecific competition.
22. Refer to graph C in Model 3.
a. Describe the species of organism represented by the graph.
b. These tadpoles are confined to a limited environment. What are they all competing for in that
23. What is the minimum mean body mass required for metamorphosis of a tadpole to occur?
24. When there are only five tadpoles, how long does it take for metamorphosis to occur?
25. When the number of individuals is increased to 60, what is the effect on the time taken for
metamorphosis to occur?
26. When the number of individuals is increased to 160, what is the effect on the time taken for
metamorphosis to occur? 6 POGIL™ Activities for High School Biology 27. Propose an explanation for why the population size affects the number of weeks before metamorphosis of the tadpoles occurs. 28. The type of competition represented by graph C is referred to as intraspecific competition.
What is different about this compared to the competition seen in graph B? Ecological Relationships 7 ...
View Full Document
- Fall '19