7 - Animal Digestion (Feeding Strategies) Flashcards
What is feeding and why is it important
Feeding is the process of obtaining and ingesting food. It is essential for meeting an organism’s nutritional needs
What factors determine success in feeding
Feeding mechanisms, feeding apparatus, and behaviour all influence feeding success
What evolutionary principle underpins feeding strategies
The balance between energy intake and expenditure drives the evolution of feeding behaviours and structures
What are trophic levels
Trophic levels classify organisms based on their position in the food chain, indicating their source of energy
How does seasonality affect food availability
Food resources can vary with seasons, affecting access and requiring adaptive feeding strategies
What does feeding on individual organisms involve
Locating, identifying, subduing, and ingesting prey or food sources
Name some types of individual feeders
Carnivores, herbivores, predators, nectar feeders, gastropods, venomous feeders
How do toxic compounds aid feeding
They inflict structural damage and/or subdue prey
Examples: scorpions, spiders, jellyfish, snakes
What is suspension feeding
A feeding strategy where organisms filter small particles from water. Common in aquatic organisms
Give examples of suspension feeders
Mussels (bivalves), whale sharks, basking sharks, humpback whales (baleen whales)
What is symbiosis-based feeding
When animals obtain nutrients via mutualistic relationships with microbes
Examples of photoautotrophic symbiosis
Reef corals with photosynthetic microbes (e.g., zooxanthellae)
Examples of chemoautotrophic symbiosis
Giant tube worms with microbes near hydrothermal vents
How do ruminants use heterotrophic microbes
Microbes ferment food in specialised stomachs, producing nutrients the animal absorbs
What is a blind gut and who has it
An incomplete digestive tract with one opening, found in hydra and similar invertebrates
What is a complete digestive tract and who has it
A digestive system with two openings (mouth and anus); found in nematodes, bivalves, insects, starfish
How are the mouth and tongue specialised?
Adapted for feeding strategies; e.g., chameleons have projectile tongues
What roles do teeth and salivary glands play
Aid in mechanical breakdown and chemical digestion of food
What is the function of the oesophagus
Transports food to the stomach; in birds, the crop stores food temporarily
How does the stomach vary in vertebrates
Contains HCl and pepsinogen for protein digestion.
Variations:
Gizzard: mechanical digestion (birds)
Rumen: fermentation (ruminants)
What are ceca and their function
Blind pouches in non-ruminant herbivores; house microbes for cellulose digestion
What is the role of the intestines
Nutrient breakdown and absorption
