Interspecific Relationships Flashcards
Allelopathy
The chemical inhibition of other organism by another by the release into the environment of substances acting as germination or growth inhibitors.
A form of antibiosis in which an organism produces one or more biochemicals that influence the growth, survival and reproduction or other organisms.
There is a winner and a loser. The successful competitor obtains all the resources it requires for survival and reproduction. The loser is prevented from gaining reosurces and as a result is excluded from the area.
Aposematism
A family of anti-predator adaptations in which a warning signal is associated with the unpalatability/danger of prey to potential predators
- Beneficial for both the predator and prey as both avoud harm
Batesian mimicry
A harmless species evolves to imitate the warning signals of a harmful species directed at a potential predator of them both.
A form of defence predators in which a species evolves to appear similar to another, where either one or both are protected when a third organism cannot tell them apart. Plant and animal species.
Brood parasite
A parasite that lays eggs in another species nest in the expectation that the species will raise the parasites offspring to maturity.
Relies on others to raise their young. The host species becomes less able to raise and feed their own young.
Advantage: No investment in rearing young, more time to forrage, produce offspring etc, lesser risk of egg loss to predators, survive to reproduce
Interspecific Relationship
Between an organism and another species. One organism always benefits.
Camouflage
Body structures and/or coloration that makes an organism blend in visually with its environment.
- Colour patterns that resemble the background of their environment
- Disguisng themselves in order to resemble something that is not of interest to the observer
- Bold patterns of contrasting stripes of spots that confuses an observer’s visual processing, especially when they are moving rapidly
Commensalism
A type of interspecific relationship in which one species benefits while the other is unaffected.
Epiphyte
A plant that grows on another plant, especially one that is not parasitic
Exploitation
Competition where organisms indirectly compete with other organisms for resources to limit the resources availability to other organisms.
Gause’s Principle
The principle that similar species cannot/will not co-exist (for long) in the same ecological niche.
Habitat
The place where an organism or a population normally lives or occurs.
Found within the optimum range for its tolerance to the abiotic factors in the environment.
Hemi-parasitic
A parasite that only gets a portion of its nutrient requirements from its hosts
Herbivory
The ingestion of plant material by herbivores. It usually does not involve the consumption and death of the entire plant.
The herbivore gains nutrients to survive and reproduce.
Reduces the plant’s ability to convert nutrients and energy into offspring as these tissues are lost. Therefore, natural selection favours plant traits that limit the negative impact of herbivores.
Plants sometimes develop mechanisms to defend themselves, e.g: thorns, unpalatable compounds in their leaves, thigmonastic responses that deter or startle herbivores.
Many fruit-bearing plants rely on animals to disperse the seeds.
Interspecific competition
Competition for resources between members of different species.
Causes the exclusion of one species by the other.
Mullerian mimicry
Mullerian mimicry occurs when two or more poisonous species share one or more common predators and have come to mimic each other’s warning signals. A predator that has learnt to avoid one species will avoid all other similar-looking species.
Occurs when two different species evolve the same/very similar structures and/or colouration as warnings to potential predators
Mutualism
A type of interspecific relationship where both species benefit from the interaction.
For example: The goby and nearly blind shrimp live in the same burrow in the sand. When a predator comes the goby touches the shrimp to warn it. The Goby gets shelter and the shrimp gets a warning about predators.
Niche
Where an organism fits into an ecological community or ecosystem
Parasitism
A type of interspecific relationship where one species (the parasite) benefits at the expense of a host species on, or in which it lives.
- Parasite can feed, grow, mate and reproduce
For example: A mosquito is a parasite that benefits from a mammal. The mosquito has increased nutrition. The mammal has decreased vigour and possibility of disease.
Predation
The act of killing and consuming a prey animal.
An example of exploitation. One organism is the predator and the other is the prey.
- Influence population numbers in the short term, in the long term influences genetic fitness and, therefore, evolution of both predators and prey
Predator
An animal that relies upon the hunting, killing and consumption of prey animals.
Predators must exhibit traits that allow them to successfully capture prey and feed. Traits are tend to be selected by natural selection.
For example: camouflage - blend into background, eye position - see prey animals, teeth/claws - killing their prey, speed and strength, teamwork
Prey
An animal that is pursued by another animal species that intends to kill and consume it
Symbiosis
Occurs when two species live in close proximity and interact because one or both cannot survive without the other.
At least one species benefits. For the other species the interaction may be positive (+), negative (-) or neutral (0)
What are some benefits that an organism may have from a symbiotic relationship?
Increased nutrient supply, increased nutrition, safety from predators, shelter, safe nest site, less parasites and predation
What is a parasitic plant?
A plant that derives nutrients from another plant. They have modified roots, called haustorium, that penetrate the host plant’s bark and connect to the xylem, phloem or both.
What is an obligate parasitic plant?
An obligate parasite is totally dependent upon its host for nutrition
What are the advantages of being a hemiparasitic plant?
- Can gain some nourishment from host and create its own
- Getting nutrition from host increases rate of growth and reproduction
- Saves biological energy involved in building root and trunk structures to absorb soil moisture and nutrients
- Gains access high light levels in the canopy, supported by the host plant
What is a disadvantage of plant parasitism?
Dependence on the health and survival of the host plant. If the host becomes diseased the parasite may be threatened.
What are some advantages of being an epiphyte?
- Gaining high light intensity and high quality light for photosynthesis
- Saves significant biological energy and growing time involved in growing a trunk to support the foliage at the canopy level
What are some disadvantages of being an epiphyte?
- Risk being dislodged due to high winds or other disruptions
- Falling off the host plant
- Disease of the hist tree and dessication during droughts as the epiphyte does not have its own root system
What is a chemical defense?
A plant produces organic compounds with chemical properties that directly deter herbivores from feeding on them. Chemical deterrents can take form of noxious odours, bitter oils, or cause excessive stimulation. Some compounds become toxic after ingestion.
What is a structural defense?
Structural defences may discourage herbivores consumption. These include thorns, spines and hairs that discourage animals by causing physical damage or by inducing rashes and allergic reactions. Plants may also produce thick, waxy leaves that make browsing and digestion difficult.
Morphological defences
Structural adaptations such as horns, spikes, stingers and toxins etc. Some may relate to the prey’s appearance to avoid detection (camouflage, mimicry).
Developed over time through evolution/natural selection. Assist prey in protecting themselves against predators.
Behavioural defences
Involve acts performed by the prey to avoid or reduce predation. These include actions such as pursuit deterrent signals, nocturnality and group living.
Aggressive mimicry
Form of mimicry in which predators share similar features with a harmless model, allowing them to avoid being correctly identified by their prey.
Stratification
The vertical layering of species in one location where environmental gradients are caused by the species present.
Zonation
The division of a community into distinct zones based on gradients such as altitude.
Banding across an area where an environmental gradient already exists.
