Ecological Niches

• ecological niche is the role and position a species has in its environment
• Obligate aerobes ▪ Require oxygen for respiration
• Obligate anaerobes are poisoned by oxygen since they live in an anoxic environment
• Facultative anaerobes can survive with or without oxygen
• Holozoic nutrition meaning swallowing the food, absorbing nutrition, and egesting the remaining thats not used
• Outline the process of human holozoic nutrition

  • Ingestion
  • Digestion
  • Absorption
  • Assimilation
  • Egestion
• Mixotrophy is a mix of both heterotrophic and autotrophic processes
• Euglena algae can perform both heterotrophy and autotrophy
• Saprotrophs are heterotrophic organisms that seecrete digestive enzymes to dead organic matter (fungi)
• Detrivores are heterotrophs that obtain nutrients by consuming and swallowing detritus
• Methanogens are archaea that can produce methane as they are lithotrophs (using inorganic source of energy) but they use an organic source of carbon
• Halophiles require salt and sunlight as energy, they are aerobic and use organic materials
• Thermophiles are found in extremely hot or acidic locations, can be either lithotrophs or organotrophs, take in sulfur as their energy source
• Hominins are humans and are direct ancestors since they split from chimps
• Humans are diphyodonts wherein in decidual teeth are replaced with new ones
• Teeth of herbivores are strong and flat molars which are adapted for grinding leaves
• Teeth of carnivores have canine teeth for tearing meat
• Canines - for tearing and piercing meat
• Incisors - nip and cut food
• Premolar with cusps - grinding and crushing (horse)
• Molars with cusps -grinding and crushing (cattle)
• Ruminants can absorb or digest grass as theres 4 stomach (cows)