Ecological niches

• What is the place where a species lives called?

  Habitat
• What is a niche in ecology?

  The role of a species within its habitat
• What are some aspects of a species' role in its niche?

  What it eats, which species depend on it for food, its activity time, and feeding location
• What happens if two species occupy the same niche?

  They will be in direct competition for resources, leading to one species out-competing the other
• How can species appear to occupy the same niche without direct competition?

  They may have subtle differences in their roles, such as feeding at different times or using different food sources
• What is an example of a feature that may differ between niches?

  Feeding location
• Why must species be adapted to their ecological niche?

  To survive in habitats where they are well adapted
• What are abiotic factors that species must adapt to?

  Light availability for plants and oxygen absorption for aquatic organisms
• What are biotic factors that species must adapt to?

  Prey camouflage and competition for sunlight
• What is aerobic respiration?

  Respiration that requires oxygen
• What is anaerobic respiration?

  Respiration that does not require oxygen
• What are obligate anaerobes?

  Organisms that can only carry out anaerobic respiration and cannot tolerate oxygen
• Where can obligate anaerobes be found?

  In oxygen-free environments like lower soil layers and deep water
• What are facultative anaerobes?

  Organisms that mainly respire aerobically but can switch to anaerobic respiration when oxygen is absent
• Give an example of a facultative anaerobe.

  Escherichia coli
• What are obligate aerobes?

  Organisms that cannot survive without oxygen and rely on aerobic respiration
• Name an example of an obligate aerobe.

  Most animals
• What is the process of photosynthesis?

  It is the process by which autotrophs convert carbon dioxide into organic molecules using light energy

  
• What are photoautotrophs?

  Autotrophs that use light energy to synthesize their own organic molecules
• Why are photosynthetic organisms known as producers?

  Because they make their own organic molecules without relying on other organisms
• What is the significance of photosynthesis in ecosystems?

  It transfers light energy into a chemical form usable by living organisms and releases oxygen
• Name some photosynthetic organisms.

  Plants, algae, and photosynthetic bacteria
• What is holozoic nutrition?

  Nutrition involving ingestion, digestion, absorption, and assimilation of organic molecules from other organisms
• What is ingestion in the context of holozoic nutrition?

  Eating
• What is digestion in holozoic nutrition?

  Breaking down larger molecules into smaller molecules
• What is absorption in holozoic nutrition?

  The transport of molecules from the digestive tract into the cells
• What is assimilation in holozoic nutrition?

  Using molecules to build cells and tissues
• How do some animals, like houseflies, differ in their feeding method?

  They secrete enzymes onto their food before absorbing the products, which is not holozoic nutrition
• What are mixotrophs?

  Organisms that can use more than one method of nutrition, such as auto- and heterotrophy
• What is an example of an obligate mixotroph?

  Organisms that must constantly have access to both methods of nutrition
• How does Euglena utilize both autotrophic and heterotrophic nutrition?

  Euglena can take in bacterial cells and digest them while also using light for photosynthesis
• What are carnivorous plants?

  Plants that build organic molecules using both photosynthesis and nutrients from digested insects
• What are saprotrophs?

  Heterotrophs that ingest the tissues of dead organisms and waste material through external digestion
• How do saprotrophs differ from holozoic nutrition?

  Saprotrophs digest food externally, while holozoic nutrition involves internal digestion
• What role do saprotrophs play in ecosystems?

  They release nutrients locked in dead and waste matter, making them available for plants
• What are the different types of archaea based on their nutrition?

  Phototrophic, chemotrophic, and heterotrophic archaea
• What do phototrophic archaea use to generate ATP?

  Energy from light
• How do Halobacteria generate ATP?

  By using a pigment called bacteriorhodopsin to absorb light energy and pump H ions across a membrane
• What are chemotrophic archaea?

  Archaea that produce their own carbon compounds using energy released from chemicals in the environment
• What are some chemicals that can act as energy sources for chemosynthetic archaea?

  Hydrogen gas, ammonia, methane, and hydrogen sulfide