B4.2  Ecological Niches

Guiding Questions:  
Guiding questions help students view the content of the syllabus through the conceptual lenses of both the themes and the levels of biological organization.

• What are the advantages of specialized modes of nutrition to living organisms?
• How are the adaptations of a species related to its niche in an ecosystem?

​​Linking Questions:  
Linking questions strengthen students’ understanding by making connections between topics.  The ideal outcome of the linking questions is networked knowledge.

• What are the relative advantages of specificity and versatility?
• For each form of nutrition, what are the unique inputs, processes and outputs?

Resources:

• At SHS, Topic B4.2 is taught in the Earliest Cells, Light and Pigments, Adaptations, Niches and Energy Flow units. 
• Quizlet study set for this topic.  Coming soon!
• View the general sequence of the SHS course
• View the SHS units mapped to the IB Biology curriculum roadmap

B4.2.1— Ecological niche as the role of a species in an ecosystem.  

• Define a niche. 
• State factors that determine the niche of a species.​
• Compare niche generalists and specialists.
  

B4.2.2— Differences between organisms that are obligate anaerobes, facultative anaerobes and obligate aerobes.

• Compare the different oxygen requirements of obligate anaerobes, facultative anaerobes and obligate aerobes.

B4.2.3— Photosynthesis as the mode of nutrition in plants, algae and several groups of photosynthetic prokaryotes.

• State the energy and carbon sources utilized in photosynthesis. 
• List three groups of photosynthetic autotrophs. ​

B4.2.4— Holozoic nutrition in animals.

• Outline the acquisition of energy and matter by holozoic animals. 
• Distinguish between ingestion, digestion, absorption and assimilation.​

B4.2.5— Mixotrophic nutrition in some protists.

• Outline the acquisition of energy and matter by mixotrophic protists. 
• State an example of a mixotrophic protist.
• Distinguish between obligate and facultative mixotrophs.​

B4.2.6-  Saprotrophic nutrition in some fungi and bacteria.

• Outline the acquisition of energy and matter by saprotrophic organisms. 
• Compare location of digestion in saprotrophs and detritivore animals. 
• List two example saprotrophic organisms.
• Explain why all saprotrophs are decomposers but not all decomposers are saprotrophs.

B4.2.7- Diversity of nutrition in archaea.

• List the three domains of life.
• Outline the characteristics of archaea.
  
• Compare the energy source and carbon source in chemoautotrophs and photoautotrophs.

B4.2.8-  Relationship between dentition and the diet of omnivorous and herbivorous representative members of the family Hominidae.

• List extinct and extant representatives of the Hominidae family of primates.
• Outline the physiological, morphological and/or behavioral adaptations of mammalian teeth for different diet types.
• Deduce the diet of an organism given dentition patterns.

B4.2.9- Adaptations of herbivores for feeding on plants and of plants for resisting herbivory.

• Outline the physiological, morphological and/or behavioral adaptations of leaf eating insects  for feeding on plants.
• Outline the physiological, morphological and/or behavioral adaptations of plants for resisting herbivory.​

B4.2.10-  Adaptations of predators for finding, catching and killing prey and of prey animals for resisting predation.

• Outline the chemical, physical and/or behavioral adaptations of predators for finding, catching and killing prey.
• Outline the chemical, physical and/or behavioral adaptations of prey animals for resisting predation.​

B4.2.11- Adaptations of plant form for harvesting light.

• Describe examples of adaptations for harvesting light, including height, lianas, epiphyte, shade-tolerance, and leaf surface area. ​

B4.2.12- Fundamental and realized niches.

• Distinguish between the fundamental and realized niche. ​

B4.2.13- Competitive exclusion and the uniqueness of ecological niches.

• Explain competitive exclusion as a factor that can limit the distribution of a species in an ecosystem.   
• Explain why two species cannot survive indefinitely in the same habitat if their niches are identical.
• State that organisms that can adapt to extreme niches encounter less competition and predation.​