Modes of nutrition

• What do living organisms need to survive, grow, and reproduce?

  Energy and raw materials
• What are the types of autotrophic nutrition?

  • Autotrophic
  • Photoautotrophic
  • Chemoautotrophic
• What is autotrophic nutrition?

  Creating organic chemicals from inorganic substances
• What is photoautotrophic nutrition?

  Using light energy to create organic chemicals
• What process do photoautotrophs use to create organic compounds?

  Photosynthesis
• What is the equation for photosynthesis?

  Carbon dioxide + water -> glucose + oxygen
• How do photoautotrophs produce organic compounds?

  By adding atoms of other elements
• What energy source do chemoautotrophs use?

  Chemical energy
• Where do many chemoautotrophs belong?

  Members of Achaea
• What does Methanococcus use as an energy source?

  Ethanoic acid
• What are the two main types of autotrophic nutrition?

  Photoautotrophic and chemoautotrophic
• What is the process of photoautotrophic nutrition?

  Combining carbon dioxide and water using light energy to produce organic compounds
• What are the key differences between photoautotrophs and chemoautotrophs?

  Photoautotrophs use light energy, chemoautotrophs use chemical energy
• What are the main sources of energy, carbon, nitrogen, phosphate, and vitamins/minerals that heterotrophic organisms need?

  Complex organic chemicals from other organisms
• What is the key difference between saprotrophic and holozoic nutrition?

  Saprotrophic involves extracellular digestion, holozoic involves ingestion and intracellular digestion
• How do parasites obtain nourishment from their host organisms?

  At the expense of the host, usually causing harm to the host
• What are the key structural adaptations of tapeworms to live in the digestive system of their host?

  Scolex with hooks and suckers, no digestive system, flat body, thick cuticle, anaerobic respiration, hermaphroditic reproduction
• How do ectoparasites like headlice differ from endoparasites like tapeworms in their relationship with the host?

  Ectoparasites live on the outside of the host, endoparasites live inside the host
• What are the key differences between obligate parasites like dodder and semi-parasitic plants like mistletoe?

  Obligate parasites like dodder cannot photosynthesize and fully depend on the host, semi-parasites like mistletoe can photosynthesize but still obtain some nutrients from the host
• How does holozoic nutrition differ from saprotrophic and parasitic nutrition?

  Holozoic involves ingestion and intracellular digestion of food, rather than extracellular digestion or obtaining nutrients from a host
• What are the key advantages of the digestive system in multicellular holozoic animals compared to single-celled holozoic organisms?

  Multicellular animals can digest a wider range of foods more efficiently through extracellular digestion
• What are the key differences between the main types of autotrophic and heterotrophic nutrition?

  Autotrophic:

  • Photoautotrophs use light energy, chemoautotrophs use chemical energy
  • Both produce organic compounds from inorganic substances

  
  

  Heterotrophic:

  • Saprotrophs digest dead organic matter externally
  • Parasites obtain nutrients from a living host, usually causing harm
  • Holozoic organisms ingest and digest organic matter internally
• What are the key structural adaptations of tapeworms to live in the digestive system of their host?

  • Scolex with hooks and suckers to attach to gut wall
  • No digestive system, just absorb nutrients
  • Flat body to increase surface area for absorption
  • Thick cuticle resistant to digestive enzymes
  • Anaerobic respiration due to lack of oxygen
  • Hermaphroditic reproduction to self-fertilize
• How do obligate parasites like dodder differ from semi-parasitic plants like mistletoe?

  Obligate parasites:

  • Cannot photosynthesize at all, fully dependent on host
  • E.g. dodder

  
  

  Semi-parasites:

  • Can photosynthesize but still obtain some nutrients from host
  • E.g. mistletoe
• What is the formula for the area of a circle with radius r?

  $A =$$\pi r^2$
• If a circle has a radius of 5 cm, what is its area?

  $25\pi \text{ cm}^2$