B4.2 ecological niches (year 6) Flashcards
abiotic interactions within a niche
non-living things like sunlight, soil type, pH and temperature
Biotic factors
provision of shelter, feeding relationships, competition between species that affect the reproduction and survival of a population
Difference btwn Obligate anaerobes, facultative anaerobes, obligate aerobes?
Obligate anaerobes:
- single-celled organisms
- no tolerance to oxygen (poisoned by it)
- live in places where air cannot reach them such as deep waters.
Facultative anaerobes:
- capable of carrying out anaerobic and aerobic respiration.
- when oxygen is not present can switch to anaerobic respiration to survive.
Obligate aerobes:
- require oxygen to survive
- unable to convert food nutrients into energy without oygen, affecting survival.
Photosynthesis in prokaryotes
Organisms that carry out photosynthesis have chlorophyll (and chloroplasts).
Found in aquatic and terrestrial plants
can convert inorganic matter into food
What are Autotrophs?
organisms that can make their own food from inorganic food substances using techniques like photosynthesis.
can be called producers
What are heterotrophs?
organisms that cannot make their own food but rely on eating other organisms.
How do heterotrophs get their nutrition?
Through holozoic nutrition which means ingesting all or parts of the organism.
organisms are ingested, digested, absorbed and assimilated into the body.
What are mixotrophs and their mode of nutrition?
They are both autotrophic and heterotrophic, capable to making own food and ingesting nutrients.
Mixotrophic nutrition:
photosynthesis occurs for them to make their own food but when levels of sunlight are low, they can ingest food from water around it.
Obligate mixotrophs need both systems to grow and thrive, facultative mixotrophs can survive on one system and use the other as a supplement.
What are saprotrophs and their mode of nutrition?
Saprotrophs live on or in non-living organic matter. Can be known as decomposers as they break down waste materials for food.
e.g. Mushrooms grow on the fallen tree trunk by secreting enzymes into the dead tree trunk to break it down.
Diversity in nutrition of archaea
Archaea are metabolically diverse.
They can use light, oxidation of inorganic chemicals or oxidation of carbon compounds to provide energy for ATP production.
Produce own food through chemical reactions (without sunlight) through chemoautotrophs.
Connection between dentition and diet [not sure if impt]
herbivores – large incisors and wide premolars, molars have rounded peaks and valleys
carnivores– sharp and pointy teeth with incisors and canines. Premolars and molars are serrated and narrow
omnivores – canines are as long and pointed as carnivores, molars of intermediate width
looking at microwear can determine the abrasions on tooth surface and thus, the type of food that they eat
How are herbivores adapted to eating plant material?
aphids and small insects have modified mouthparts, known as stylets
grasshoppers and caterpillars have mandibles to cut through blades of grass.
herbivorous vertebrates have ruminants where they swallow before chewing then regurgitate later to chew more
How do plants protect themselves from herbivores?
- thick barks, thorns, spikes and secrete chemical irritations when animals rub against the plant as a warning
- release phytotoxins which can cause health problems
- some animals have metabolic processes to neutralise these phytotoxins so they can consume the food.
Adaptations of predators to catch prey
chemical : inject chemicals or neurotoxins, use chemical compounds to send messages and attract prey into the trap.
physical: having good eyesight, echolocation ability, acute sense of smell, claws and teeth to tear meat apart for consumption
e.g. Ampullae of Lorenzini in sharks to detect changes in electromagnetic fields.
behavioural: ambush predators (setting up spider webs), lure predators with illicium (anglerfish) and pack hunting
pursuit predator needs to have persistence hunting with good fitness and endurance to outrun prey.
How do animals resist predation?
chemical: production of poison to dissuade predators from consuming them.
physical: camouflage to avoid detection of predator, aposematism OR having bright colours as a warning of poisonous or venomous creatures OR growing a protective shell and having exoskeletons.
behavioural: other than the common fleeing at the sight of predator and formation of groups, travelling in large herds prevents attackers from targeting specific people in the group.
Adaptations of plant form for harvesting light
- Trees
They are strategically placed in forests according to height; canopy, understory, forest floor and each forest layer allows trees of varying heights to receive optimal sunlight - Lianas
borrow support from nearby trees. They take root in other trees and climb them to reach sunlight. However, they compete with the trees for sunlight and minerals - Epiphytes
Attach themselves to the roots of tree trunks. They grow upwards on trees and the push downwards to root themselves. - Shade
some plants grow in the shade well. absorb remaining sunlight that diffuses through – usually those of longer wavelengths.
What is a fundamental niche?
Refers to the potential niche that a species could inhabit given the adaptations and its tolerance limits.
What is a realised niche?
Actual niche areas belonging to the species. The realised niche is smaller than the fundamental niche due to competition for resources with other organisms.
The principle of competitive exclusion
The principle states that no 2 species in a community can occupy the same niche. They can coexist for a period of time but afterwards, one species will die out while the other will thrive due to interspecific competition.
Only way to solve this is to restrict both species to part of their fundamental niche.
