How might you add “Keystone species” to the concept map?
A.) Keystone species increase competition among all populations in a community.
B.) Keystone species are the most abundant members of communities.
C.) Keystone species always live with other species in symbiosis.
D.) Keystone species influence the diversity of communities.
2.) What is the correct relationship between the abiotic environment and trophic levels? (Select all that apply.)
The resources available in the abiotic environment limit the number of trophic levels in a community.
Fat soluble chemicals that organisms at low trophic levels obtain from the abiotic environment will decrease in concentration in the higher trophic levels.
Organisms at the lowest trophic level of a community obtain nutrients directly from the abiotic environment.
Some of the energy that producers obtain from the abiotic environment is lost at each trophic level.
3.) Herbivory has the same effect on species in a community as
competition.
mutualism.
commensalism.
parasitism.
The Correct Answer and Explanation is :
Here are the answers to your questions, along with a detailed explanation:
1. Keystone Species
Correct Answer: D.) Keystone species influence the diversity of communities.
Explanation: Keystone species play a critical role in maintaining the structure of an ecological community. Their presence or absence can significantly impact the diversity of species within that community. For instance, the removal of a keystone predator can lead to an overpopulation of prey species, which can, in turn, lead to a decrease in plant diversity due to overgrazing. This concept highlights that not all species have equal importance in an ecosystem; some, like keystone species, have a disproportionate effect on their environment.
- Option A is incorrect because while keystone species can influence competition, they do not universally increase competition among all populations.
- Option B is misleading, as keystone species are not necessarily the most abundant; they can be rare yet still have a significant impact.
- Option C is incorrect; keystone species do not always engage in symbiotic relationships.
2. Relationship Between Abiotic Environment and Trophic Levels
Correct Answers:
- The resources available in the abiotic environment limit the number of trophic levels in a community.
- Organisms at the lowest trophic level of a community obtain nutrients directly from the abiotic environment.
- Some of the energy that producers obtain from the abiotic environment is lost at each trophic level.
Explanation: The abiotic environment, which includes non-living components such as sunlight, water, and nutrients, significantly affects the number of trophic levels that a community can support. For example, if resources are scarce, fewer trophic levels will be able to sustain themselves. Producers (plants and photosynthetic organisms) harness energy from the abiotic environment, which they convert into biomass. However, a significant portion of this energy is lost at each subsequent trophic level due to metabolic processes (like respiration) and inefficiencies in energy transfer, generally around 90% loss as you move from one level to the next.
Incorrect Statement:
- Fat soluble chemicals that organisms at low trophic levels obtain from the abiotic environment will decrease in concentration in the higher trophic levels. This statement is incorrect; instead, fat-soluble chemicals often bioaccumulate and magnify in concentration as they move up the trophic levels, leading to higher concentrations in top predators.
3. Herbivory Comparison
Correct Answer: Competition.
Explanation: Herbivory can have similar ecological effects as competition because both involve the consumption of resources that are limited. When herbivores feed on plants, they reduce the availability of those plants for other herbivores, similar to how competition occurs among species vying for the same resources. Both processes can affect the population dynamics and distribution of species within a community. For instance, heavy herbivory can lead to reduced plant biomass, which in turn may limit the resources available for other herbivores, much like how competition can restrict access to food, space, or mates among organisms.
In summary, while herbivory is a form of species interaction distinct from competition, its effects on resource availability can mimic competitive interactions, influencing species composition and diversity in an ecosystem.