Feeding and Digestion Flashcards
Define feeding and digestion.
Feeding: the gathering and ingestion of food.
Digestion: processing to transfer required nutrients into the body of the consumer.
Define heterotrophic.
To have to obtain nutrients from other organisms.
What is small particle feeding?
Various forms of suspension feeding & detritivory feeding.
What is large particle feeding?
Deposit feeding, herbivory & predation.
Define deposit feeding.
Ingestion of substratum to extract its organic content.
What is herbivory?
ingestion of non phytoplanktonic plant material.
What is fluid feeding?
Piercing and sucking of plant/animal juices, direct uptake of DOM.
Describe suspension feeding.
Found in many phyla. Porifera - choanocytes. Using cilia or mucous.
What is external mucociliary food capture?
External, constant production of mucous on cilia to capture food.
What is external setose particle capture?
Using chaetae, different size faction - small multicellular organisms.
What is non-ciliated mucous particle capture?
Production of mucous nets or mucous string. Similar to countercurrent flow only more mucous not food.
What are mucociliary deposit feeders?
Echiurians. They put up a structure at the top of their burrow and hoover up stuff around it. Gutter-like structure that sweeps over surface and particles get stuck to mucous on it.
What are sediment interceptors?
They are dependent on material re-suspended near-bottom currents. They sit in the currents and intercept near-bottom later of resuspended particles.
What are various fluid-feeding methods?
Piercing and rasping suckers, or taking up DOM directly from the water.
What did the evolution of a through gut achieve?
It allowed for continuous food processing, which increases the ability to process bulky and low quality food. It also makes it possible to change the mechanical and chemical processes along the length of the gut, e.g. changing pH.
What is the fore gut made of?
It is ectodermal in origin with an ectodermal lining.
What is the mid and hind gut made of?
They are both endodermal in origin and lining, often with diverticula.
What is the fore gut made up of?
The buccal cavity, the pharynx, and the oesophagus.
What is the mid gut made of?
A muscular stomach, secretory/absorptive caeca and intestines.
What is the hind-gut contain?
The rectum and anus.
How do mucociliary suspension feeders move their food?
Chordates, lophophorates and filterfeeding molluscs pass food into the stomach in a cord of mucous. The stomach acids allow particles to be released but the alkaline gut restores the viscosity to help form faecal pellets.
How do the suspension feeders move the mucous cord?
In chordates: moved by cilia on the bars of the pharyngeal basket. In lophophorates: winched by a rod of material turned by cilia. In molluscs: the rod is large and permanent & called the crystalline style. It contains digestive enzymes.
How do deposit feeders process their food?
They have a long capacious gut that allows for prolonged digestive processing.
What is an example of suspension feeding?
An echiuran.
What is an example of fluid feeding?
Agnathan
What are the three main functional regions of the gut and what do they do?
Foregut: capture and initial mechanical processing.
Midgut: enzymatic breakdown and absorption
Hindgut: packaging and removal of waste
