Ecology Flashcards
ECOLOGICAL MANAGEMENT
In ecological management
Associations in an ecosystem
In ecosystems
Competition among photosynthetic producers
Photosynthetic producers compete for sunlight
Competition among consumers
Consumers compete for ready-made food (in the form of other living organisms and their products) and living space.
Predation
Predation is the common form of feeding interaction among consumers. It is the act of preying on another consumer. In any ecosystem
Prey that are primary consumers
Prey that are primary consumers feed on plants or detritus and so are not faced with the uncertainty of hunting for food (though when food is scarce they may starve or migrate).
Overcoming unsatisfactory situations
To overcome such an unsatisfactory situation
Symbiosis
Symbiosis is any close and prolonged living together or association of two or more organisms of different species. The partners in a symbiosis may be all consumers; consumers and producers; producers and saprophytes; consumers and saprophytes; and so on. The relationship in a Symbiosis may be temporary or permanent; and harmful
Parasitism
Parasitism is an association in which one organism
Ectoparasites
Parasites like ticks
Endoparasites
Endoparasites live inside the bodies of their hosts. Examples include the roundworms
Parasitic associations
Some parasitic associations are very short-lived as in the case of the leech or the tsetse-fly that feeds on the human blood. Such associations are often not considered as parasitic. Longer-lived associations occur in the case of many ectoparasites such as lice
Benefits to parasite
Most parasites get both food and shelter from their hosts. The endo- parasites especially have the best benefits since they are in an environment which protects them from other consumers and provides their energy requirements (food) with very little effort on their part.
Harm suffered by host
In most parasitic associations
Parasitic adaptations
A parasite must: be able to cling on to the host’s body surface (mainly ectoparasites and gut parasites)
Parasitic fungi
Fungal parasites are very common on green plants. The hyphae of the parasite enter the host’s body through stomata and branch in between the cells. The hyphae produce enzymes to dissolve the cell walls and open up a path.
Parasitic plants
Dodder
Parasitic animals (ectoparasites)
Animals that are ectoparasites have attachment structures such as claws
Parasitic animals (endoparasites)
A parasite that lives inside its host’s body is usually highly specialized for its mode of life. It can only live on a specific type of host or a limited range of hosts. As a result
Tapeworms
Tapeworms are long parasitic flatworms which live in the gut of humans. Several species of tapeworms infect human
Tapeworms’ mode of life
Like most endoparasites
Tapeworms’ life cycle
The life cycle of the tapeworm involves two hosts: a human being who is re- garded as the primary host and another animal
Economic importance of tapeworms
Tapeworms do not cause any severe disease in humans
Control of tapeworms
Infestation of humans by these worms can be prevented by having all meat for sale examined by health inspectors so as to ensure that bladderworms are absent. Further- more
Blood Fluke
The blood fluke is a long parasitic flatworm known as Bilharzia or Schistosoma. It causes bilharziasis or schistosomiasis. This disease is widespread in Africa
Roundworms and Hookworms
Roundworms and hookworms are common roundworm
Effects of Roundworms and Hookworms
Roundworm infestation causes poor health and anaemia.
Effects of Roundworms and Hookworms
Roundworm infestation causes poor health and anaemia. Hookworms also cause anaemia as they suck blood. They also cause tiredness and retarded growth in children.
Control of Roundworms and Hookworms
Roundworm infestation can be controlled by proper sanitation. This prevents the contamination of food and water by faeces. Hookworm infection can be prevented by wearing shoes to avoid contact with the larvae in the soil.
Mutualism
Mutualism is an association in which both organisms benefit. Many examples of mutualism are found among living organisms.
Examples of Mutualism
Some of the examples include: the association between nitrogen-fixing bacteria and leguminous plants; the association between termites and the protozoa in their gut; the association between cellulose-digesting bacteria and ruminants; and lichens.
Nitrogen-fixing bacteria and leguminous plants
Leguminous plants have nodules in their roots. These nodules contain nitrogen-fixing bacteria of the genus Rhizobium. The bacteria convert nitrogen gas from the atmosphere into nitrates which the plant can use to synthesize proteins. The plant in turn provides the bacteria with carbohydrates and other organic nutrients.
Termites and protozoa in their gut
Termites feed on wood which contains cellulose. However
Cellulose-digesting bacteria and ruminants
Ruminants are animals which have a four-chambered stomach. They include cattle
Lichens
Lichens are organisms which are made up of an alga and a fungus living together. The alga manufactures food for both organisms by photosynthesis. The fungus absorbs water and mineral salts for the alga and provides it with physical support.
Commensalism
Commensalism is an association in which one organism benefits while the other is neither harmed nor helped.
Examples of Commensalism
Examples of commensalism include: the association between the remora fish and the shark; the association between the epiphytes and the trees on which they grow; and the association between hermit crabs and empty gastropod shells.
Remora fish and the shark
The remora fish has a sucker on its head with which it attaches itself to the shark. In this position
Epiphytes and trees
Epiphytes are plants which grow on other plants without harming them. They include orchids
Hermit crabs and empty gastropod shells
Hermit crabs have soft abdomens which are not protected by a shell. They therefore live in empty gastropod shells for protection. As the crab grows
Saprophytism
Saprophytism is the relationship in which an organism obtains its food from dead organic matter. Organisms that live in this way are known as saprophytes.
Examples of Saprophytes
Examples of saprophytes are bacteria and fungi. They secrete enzymes onto dead organic matter and digest it externally. The soluble products are then absorbed into their bodies.
Ecological Adaptations
Ecological adaptations are the structural
Structural adaptations
Structural adaptations are the physical features of an organism’s body.
Physiological adaptations
Physiological adaptations are the internal working of an organism’s body.
Behavioural adaptations
Behavioural adaptations are the actions and reactions of organisms.
Adaptations for feeding
Adaptations for feeding are the structural
Adaptations for protection
Adaptations for protection are the structural
Adaptations for reproduction
Adaptations for reproduction are the structural
Adaptations for feeding in Amoeba
The Amoeba is a free-living protozoan that lives in freshwater habitats. It is a heterotroph
Adaptations for feeding in Paramecium
The Paramecium is also a free-living protozoan that lives in freshwater habitats. It is a heterotroph
Adaptations for feeding in a named insect
The cockroach is a common insect that lives in dark
Adaptations for feeding in a named bird
The pigeon is a common bird that lives in a variety of habitats. It is a granivore
Adaptations for protection in Amoeba
The Amoeba has the following adaptations for protection: ability to move away from harmful stimuli; ability to form a cyst under unfavourable conditions.
Adaptations for protection in Paramecium
The Paramecium has the following adaptations for protection: ability to move away from harmful stimuli; presence of trichocysts which are discharged when the organism is irritated.
Adaptations for protection in a named insect
The cockroach has the following adaptations for protection: ability to run very fast; ability to hide in cracks and crevices; a hard exoskeleton that protects it from injury.
Adaptations for protection in a named bird
The pigeon has the following adaptations for protection: ability to fly away from danger; keen eyesight.
Adaptations for reproduction in Amoeba
The Amoeba reproduces asexually by binary fission. It has the following adaptations for reproduction: ability to divide rapidly; ability to reproduce under unfavourable conditions by forming spores.
Adaptations for reproduction in Paramecium
The Paramecium reproduces asexually by binary fission and sexually by conjugation. It has the following adaptations for reproduction: ability to divide rapidly; ability to reproduce sexually which introduces variation.
Adaptations for reproduction in a named insect
The cockroach reproduces sexually. It has the following adaptations for reproduction: ability to produce large numbers of eggs; internal fertilization which protects the eggs from drying out.
Adaptations for reproduction in a named bird
The pigeon reproduces sexually. It has the following adaptations for reproduction: ability to build nests in safe places; ability to care for its young.
Ecological Niche
The ecological niche of an organism is its role in the ecosystem. It includes its feeding habits
Components of an ecological niche
An organism’s ecological niche includes: its trophic level (producer
Tolerance range
The tolerance range for a given abiotic factor is the range of that factor within which an organism can survive and reproduce.
Optimum range
The optimum range is the range within which the organism grows and reproduces best.
Zones of stress
Outside the optimum range are the zones of stress
Limits of tolerance
Beyond the zones of stress are the limits of tolerance
Abiotic factor
An abiotic factor is a non-living factor in the environment
Abiotic factors and distribution of organisms
Abiotic factors play a major role in determining the distribution of organisms in an ecosystem. Each species has its own specific tolerance range for each abiotic factor
Ecological Succession
Ecological succession is the gradual process of change in the species structure of an ecological community over time.
Primary succession
Primary succession occurs in an area where there is no soil
Secondary succession
Secondary succession occurs in an area where the soil is intact
Pioneer species
Pioneer species are the first species to colonize a barren or disturbed area. They are typically hardy species that can tolerate harsh conditions.
Climax community
A climax community is a stable
Human Impact on Ecosystems
Human activities have had a significant impact on ecosystems around the world. These impacts include: habitat destruction
Habitat destruction
Habitat destruction is the process by which natural habitats are altered or destroyed
Pollution
Pollution is the introduction of harmful substances into the environment
Introduction of exotic species
Exotic species are species that are introduced into an area outside their native range. They can outcompete native species and disrupt the balance of the ecosystem.
Overexploitation of resources
Overexploitation of resources is the unsustainable use of natural resources
Climate change
Climate change is a long-term change in the average weather patterns that have come to define Earth’s local
Remedial Efforts
There are many efforts being made to remedy the negative impacts of human activities on ecosystems. These efforts include: conservation
Conservation
Conservation is the protection and management of natural resources and biodiversity.
Restoration
Restoration is the process of assisting the recovery of an ecosystem that has been degraded
Sustainable development
Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
Pyramid of numbers
A pyramid of numbers is a graphical representation of the number of organisms at each trophic level in a food chain or food web.
Pyramid of biomass
A pyramid of biomass is a graphical representation of the total biomass of organisms at each trophic level in a food chain or food web.
Pyramid of energy
A pyramid of energy is a graphical representation of the total energy content of organisms at each trophic level in a food chain or food web.
Biogeochemical cycles
Biogeochemical cycles are the pathways by which chemical substances move through the biotic and abiotic components of Earth.
Water cycle
The water cycle is the continuous movement of water on
Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere
Nitrogen cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere
Phosphorus cycle
The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere
Ecological Relationships
Ecological relationships are the interactions between organisms in an ecosystem. These relationships can be classified as: Competition
Competition
Competition is an interaction between organisms in which both are harmed. It occurs when organisms require the same limited resource
Predation
Predation is an interaction in which one organism (the predator) kills and eats another organism (the prey).
Symbiosis
Symbiosis is a close and prolonged interaction between two or more organisms of different species.
Saprophytism
Saprophytism is an interaction in which an organism obtains its food from dead organic matter.
