animal nutrition and dentition Flashcards
(25 cards)
how do reptiles and amphibeans eat?
swallow food whole
which are the only animals that have a palate separating their air path from mouth? what is the advantage to this?
mammals
allows food to be retained in mouth rather than swallowed whole between breaths
what is the gut like of a carnivore? what is its diet?
eats only animals (mostly protein diet)
gut is straight and smooth, has a short small intestine in relation to body length bc protein is easily digested
what is the gut of a herbivore like? what is its diet?
eats only plant matter
gut is pouched and accommodates for a larger volume of faeces, small inestine is long in relation to body length bc plant materials isn’t easily digested and long gut allows time for digestion and absorption of nutrients
what teeth do humans have?
incisors (8) - chisel shaped for biting and cutting
canines (4) - pointed for tearing
premolars and molars (20) flat for chewing and grinding
what are the adaptations for cellulose in herbivores?
plant cell walls are tough as contain cellulose so teeth modified to ensure food is thoroughly ground up before it’s swallowed
Describe the use of the horny pad, use example.
grazing herbivore eg cow has incisors on lower jaw only and cuts against horny pad on upper jaw
What is a diastema? its adaptations?
diastema - gap which separates front teeth from side teeth/premolars
tongue and cheeks operate in gap moving freshly cut grass to large grinding surfaces of cheek teeth or molars
What are the adaptations in herbivores for grinding food in terms of jaw movement?
jaw moves in circular motion in a horizontal plane, cheek teeth interlock like a W fitting into M
over time the grinding surfaces become worn down, exposing sharp edged enamel ridges which further increase efficiency of grinding process
how can herbivore teeth grow continuously?
have open, unrestricted roots so they can continue to grow throughout life
what are some of the adaptations in carnivore dentition for their diet?
sharp incisors to grip and tear flesh from bone
large canine teeth, curved and pointed for piercing and tearing flesh of prey
premolars and molars for cutting and crushing of bones
carnassials slide past each othe rlike scissor blades to shear muscle off bone
well developed jaw muscles, powerful to enable grip
vertical jaw movement to allow jaw to open widely for capturing prey
if comparing herbivores and carnivores, what would you compared?
use of incisors
canines
jaw movement
diastema
carnassials
premolars and molars
jaw muscles
what do ruminants mainly eat? what is the specialised organ for their diet?
mainly grass and forage
rumen
what lives in the rumen? why must this region of the gut be kept separate from the main digestive region?
mutualistic bacteria
so food can be kept long enough for bacteria to carry out cellulose digestion
so bacteria are isolated fro mammal’s own digestive juices so that they’re at optimum pH for their activities and not killed by extremes of pH
explain the process of cellulose digestion, particulalry in cows
- grass is cut by teeth and mixed with saliva, cud formed is swallowed
- in rumen cud is mixed with cellulose digesting bacteria to produce glucose, this is then fermented to form organic acids
- fermented cud passes into next region, reticulum, before regurgitating into mouth and chewed again 9may happen several times)
- cud passes into amasum, where water and organic acids made from fermented glucose are absorbed into blood
- 4th chamber, abasum is the ‘true’ stomach, functions like normal stomach where protein digested by pepsin at pH2
- digested food passed to small intestine, where products of digestion are absorbed into blood
what are rabbits? what are their adaptations for their diet?
non-ruminant herbivores
long gut so more time for cellulose digestion, mutualistic bacteria found in caecum/appendix
why are two types of faecal pellets formed?
absorption in ileum occurs prior to microbe action
green (contains cellulose and glucose nutrients)
brown (without nutrients)
rabbits eat green pellets to obtain nutrients, copraphagous
what are parasites?
live in or on another species (host)
obtain nourishment at the hosts expense
they cause harm and often death
how are bacteria parasitised? what are they called?
by viruses. called bacteriophages
describe the pork tapeworm
ribbon-like
head made up of muscle on which suckers and hooks (scolex)
its body consists of a linear series of thin sections called proglottids
what is a pork tapeworm?
obligate parasite, can only exist as a parasite inside a host
what is the primary host of a pork tapeworm? secondary? what is the process of pork tapeworm activation?
human
pig
larval form develops in pig, pig becomes infected when its food is contaminated w human faeces
humans infected by eating under cooked pork containing larval forms
what are the function and adaptations of the tapeworm?
suckers and a double row of curved hooks for attachment to wall of gut
body covering which protects them from hosts immune system
thick cuticle and production of inhibitory substances on the surface of the segments to prevent digestion by host’s enzymes
degeneration of unnecessary organs
tapeworm is thin and large SA:VOL, food can be digested over entire body surface
both males and female reproductive organs found in each segment, vast numbers of eggs produced
eggs have resistant shells and can survive until eaten by secondary host
what are the harmful effects of the tapeworm?
causes little discomfort
if eggs eaten by humans, dormant embryos form cysts in various organs and damage surrounding tissue, can be treated w/drugs
