Biology By2 Revision
Parasitic Nutrition
21 May 2011 10:43
= organisms that live on or in another organism obtaining nourishment at the expense of the host and causing harm. Gut parasite (Taenia solium) = tapeworm Primary host = human (eat uncooked infected pork) Secondary host = pig (drainage channels contaminated by human faeces) Adaptations… - Suckers & hookers (attachment) - Body covering (immune responses) - Thick cuticle (inhibitory substances = enzymes) - Simple body systems (reproduction) - Very thin & large surface area (food absorbed over whole body surface = diffusion) - Male & female sex organs (gut can only accommodate 1 tapeworm) - Number of eggs produced (increase chance of survival) - Eggs have resistant shells (survive until eaten) Dormant embryos can form cysts in organs - damage surrounding tissue
BY2 revision Page 1
Adaptions to different diets
21 May 2011 10:53
Reptiles & Amphibians = swallow food whole Mammals = cut up and chew (palate separates nasal cavity & mouth - kept in mouth longer) Carnivore = short gut (easily digest protein) Herbivore = long gut (plant digestion difficult)
Dentition Mechanical digestion = easier to swallow & increases surface area for enzyme action
Herbivore Incisors Canines Lower jaw, cuts against horny pad (upper jaw) Indistinguishable from incisors Carnivore Sharp (tear flesh from bone) Large, curved, pointed = seizing prey, killing & tearing flesh Carnassial (slide past each other = garden shears) molars = cutting/crushing) Vertical (open wide to capture & kill prey) Not horizontal (dislocation) Jaw muscles = well developed/powerful (grip firmly on prey/crush bones)
Cheek teeth Interlock. (W into M) Worn down = sharp enamel ridges (efficiency). Open roots (grinding) Jaw movement Other Circular grinding. Horizontal plane Diastema = gap between front & side teeth. Tongue moves cut grass to grinding surfaces (cheek teeth)
Ruminants Produce most protein eaten by humans eg. Cows/sheep
Mutualism/Symbiosis =
21 May 2011 10:43
= organisms that live on or in another organism obtaining nourishment at the expense of the host and causing harm. Gut parasite (Taenia solium) = tapeworm Primary host = human (eat uncooked infected pork) Secondary host = pig (drainage channels contaminated by human faeces) Adaptations… - Suckers & hookers (attachment) - Body covering (immune responses) - Thick cuticle (inhibitory substances = enzymes) - Simple body systems (reproduction) - Very thin & large surface area (food absorbed over whole body surface = diffusion) - Male & female sex organs (gut can only accommodate 1 tapeworm) - Number of eggs produced (increase chance of survival) - Eggs have resistant shells (survive until eaten) Dormant embryos can form cysts in organs - damage surrounding tissue
BY2 revision Page 1
Adaptions to different diets
21 May 2011 10:53
Reptiles & Amphibians = swallow food whole Mammals = cut up and chew (palate separates nasal cavity & mouth - kept in mouth longer) Carnivore = short gut (easily digest protein) Herbivore = long gut (plant digestion difficult)
Dentition Mechanical digestion = easier to swallow & increases surface area for enzyme action
Herbivore Incisors Canines Lower jaw, cuts against horny pad (upper jaw) Indistinguishable from incisors Carnivore Sharp (tear flesh from bone) Large, curved, pointed = seizing prey, killing & tearing flesh Carnassial (slide past each other = garden shears) molars = cutting/crushing) Vertical (open wide to capture & kill prey) Not horizontal (dislocation) Jaw muscles = well developed/powerful (grip firmly on prey/crush bones)
Cheek teeth Interlock. (W into M) Worn down = sharp enamel ridges (efficiency). Open roots (grinding) Jaw movement Other Circular grinding. Horizontal plane Diastema = gap between front & side teeth. Tongue moves cut grass to grinding surfaces (cheek teeth)
Ruminants Produce most protein eaten by humans eg. Cows/sheep
Mutualism/Symbiosis =