Exam 1: Ecology
Ecology is the study of how living organisms interact with each other and with their environment. An ecosystem is a natural unit of living (biotic) components in a given area, as well as the non-living (abiotic) factors with which they interact. An ecosystem is a major ecological unit. For example a forest consists of all the living organisms living there as well as the soil, rocks, water etc.Ecology may be studied at a population, community, or ecosystem level:
o A population is a group of organisms of a single species occupying a particular area.
o A community comprises the different populations of species that live in a habitat.
o A habitat is the particular area occupied by a population. That is, the place where an organism lives. It has biotic and abiotic features which separate it from other habitats:
• Microhabitats are small localities within a habitat, each with its own particular conditions.
• An ecological niche is the position and role of each species within an ecosystem. This is not only the physical space
which it occupies but the role which it carries out within the community and its inter-relationships with other species as well. In the long term, two species cannot occupy the same niche in a specific habitat otherwise they compete with each other.
Nutrition (please see the nutrition topic in Exam 3 for further details)
Nutrition is the process by which organisms obtain energy to maintain life functions and also the matter needed to create and maintain structure. These are obtained from nutrients.
Most autotrophic organisms use the simple inorganic materials, carbon dioxide and water, to manufacture complex organic molecules like glucose (using the energy originaslly from sunlight = photosynthesis or the energy released from inorganic chemical reactions inside cells = chenosynthesis), whereas heterotrophic organisms consume complex organic food material from their envionment (like saprophytes such as fungi, holozoic feeders like earthworms and parasites like wasp larvae).
Ecology is the study of how living organisms interact with each other and with their environment. An ecosystem is a natural unit of living (biotic) components in a given area, as well as the non-living (abiotic) factors with which they interact. An ecosystem is a major ecological unit. For example a forest consists of all the living organisms living there as well as the soil, rocks, water etc.Ecology may be studied at a population, community, or ecosystem level:
o A population is a group of organisms of a single species occupying a particular area.
o A community comprises the different populations of species that live in a habitat.
o A habitat is the particular area occupied by a population. That is, the place where an organism lives. It has biotic and abiotic features which separate it from other habitats:
- The biotic or living features of a habitat are the sum of all the organisms within that habitat and their interactions; biotic factors often affect population growth in a density-dependent manner (i.e. factors that have a gereater impact on population growth when the population number is greater) such as nutrient /food availability, availability of a mate, build up of toxic waste..
- The abiotic or non-living features of a habitat include:
- Edaphic features relate to the soil and include all its physical + chemical characteristics (e.g. pH, mineral ion content).
- Climatic features include light, temperature, moisture, salinity, and, particularly, the stability or variability of these.
• Microhabitats are small localities within a habitat, each with its own particular conditions.
• An ecological niche is the position and role of each species within an ecosystem. This is not only the physical space
which it occupies but the role which it carries out within the community and its inter-relationships with other species as well. In the long term, two species cannot occupy the same niche in a specific habitat otherwise they compete with each other.
Nutrition (please see the nutrition topic in Exam 3 for further details)
Nutrition is the process by which organisms obtain energy to maintain life functions and also the matter needed to create and maintain structure. These are obtained from nutrients.
Most autotrophic organisms use the simple inorganic materials, carbon dioxide and water, to manufacture complex organic molecules like glucose (using the energy originaslly from sunlight = photosynthesis or the energy released from inorganic chemical reactions inside cells = chenosynthesis), whereas heterotrophic organisms consume complex organic food material from their envionment (like saprophytes such as fungi, holozoic feeders like earthworms and parasites like wasp larvae).