Digestion in carnivores, herbivores and omnivores Flashcards
Define Carnivore
organisms that kills and eats animals. E.g. dingo, fox and eagle
Define Herbivore
organism that eats living plants or parts of them. e.g. cow, rabbit
Define Omnivore
organism that eats both plants and animals. E.g. human, pigs
Define Ingestion
The intake of food, liquid or drugs into the mouth or oral cavity.
Define Digestion
The chemical breakdown (enzymic) and mechanical (physical) breakdown of food into small molecules that can be absorbed by into the body.
Define Egestion/Elimination
The removal of undigested remains of food eaten
Define Physical digestion
Mechanical digestion: large pieces of food are broken down into smaller pieces of food. Chewing or grinding action of the stomach. Results in increasing the surface area of food for enzymes to act upon.
Define chemical digestion
enzymes break down complex food substances into simple sub units such as glucose, amino acids, fatty acids and glycerol.
What are 6 nutrients required by animals?
Proteins Carbohydrates Fats and lipids Vitamins e.g. Vitamin A is required for growth, skin and eyesight. Minerals Water
What are the minerals required in animals?
inorganic elements e.g. calcium is required for bone growth and maintenance, Iron is used by red blood cells to carry oxygen as haemoglobin.
What are 3 adaptations associated with ingestion?
Organisms choosing suitable foods for ingestion.
Mouth parts that assist in feeding behaviours e.g. mosquito.
Other physical features that may assist with catching food and feeding e.g. talons (eagle), body built for speed (cheetah), clasping legs (head lice).
What are 3 adaptations associated with digestion?
The structure/shape and number of an animals teeth.
Structure of the alimentary tract
Indicate the foods an animal can digest.
What kind of teeth do omnivores have?
Teeth 4 incisors for biting/cutting 2 canines similar to incisors 4 Premolars for grinding and chewing 6 Molars for chewing
Describe three factors of the alimentary tract of an omnivore?
Short simple alimentary canal.
Reduced caecum.
Inability to digest cellulose. Cellulose contributes to the fibre and undigested food products that make up faeces.
What kind of teeth do carnivores have?
Large canines for piercing and tearing
Premolars and molars have sharp points.
No flat surfaces for grinding food
Describe 5 factors of the short simple digestive system of carnivores
short small intestine, short colon and small caecum. Stomach can expand greatly.
All enzymes for the complete digestion of meat/protein are produced by the gut.
Describe how herbivores digest plant matter
Eat plant matter which contains cellulose.
Herbivores do not produce the enzyme to digest cellulose.
Describe the process of fermentation in animals
Bacteria live in the gut and convert cellulose into simpler molecules that herbivores can absorb.
This process is called fermentation
Where are the 2 places that fermentation occurs in 2 different herbivores?
Foregut fermentation = Ruminant (cow, sheep)
Hindgut fermentation = Rabbit, guinea pigs
etc
What types of teeth do ruminant herbivores have?
Teeth – some ruminants( e.g. sheep) have no upper incisors or canines as not needed.
Describe 5 factors of the alimentary tract in ruminants.
Long intestinal tract with very large caecum and appendix.
Large foregut = stomach
Stomach has 4 chambers: rumen, reticulum, omasum and abomasum.
Where do the 6 step for the process of cellulose digestion occur? In order
Mouth Rumen Reticulum Omasum Abomasum Duodenum
What occurs in the first step of cellulose digestion in the mouth?
grass is chewed and mixed with saliva into a ‘cud’ and swallowed.
What occurs in the second step of cellulose digestion in the Rumen?
- Fermentation
- Absorption
- Belch
- bacteria
cud is mixed with cellulose digesting bacteria to produce glucose, which is fermented to organic acids.
These are absorbed into the blood.
CO2 and methane are belched out.
Bacteria manufacture protein from inorganic nitrogen.
What occurs in the third step of cellulose digestion in the Reticulum?
- Regurgitation
cud is formed into balls and regurgitated into the mouth for further chewing before being re swallowed and passing into the omasum.
What occurs in the fourth step of cellulose digestion in the Omasum?
much water is reabsorbed from the cud.
What occurs in the fifth step of cellulose digestion in the Abomasum?
normal gastric secretions begin to digest proteins from the grass and bacteria.
What occurs in the sixth step of cellulose digestion in the Duodenum?
chyme passes into here and then into the small intestine where the products of digestion are absorbed.
What kind of teeth do non-ruminant herbivores have?
Sharp incisors and no canines.
What are the 4 factors non-ruminants have for their alimentary tract?
Long intestinal tract with large hind gut.
Large caecum and appendix for fermentation
How do non-ruminants absorbed their foods?
rabbits 💩
Re eats soft faecal pellets so all nutrients have been digested and absorbed. Then passes hard, dry faeces.
Define Absorption
the taking up of digestive molecules into the internal environment of the cells of the digestive tract
