The Organism in the Environment

The Organism in their Environment

Living things or organisms share seven common characteristics: movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
Remember these traits with the acronym MRS GREN.

A habitat is where an organism lives, it includes both living and non-living components.
Organisms are adapted to their habitats in a variety of ways that increase their chances of survival and reproduction.
Structural adaptations are physical features of an organism’s body; e.g., a camel’s hump stores fat.
Behavioural adaptations are ways organisms behave; e.g., polar bears hibernate in winter.
Physiological adaptations are internal body processes, for example, many desert animals conserve water.

A population is a group of individuals of the same species in a given area.
Community refers to all populations in a specific area existing together, which includes different species.
Interactions in a community include: predation, competition, and symbiosis.

An ecosystem consists of all the organisms (biotic component) in a community, plus the physical environment (abiotic component).
The physical environment includes living and non-living aspects—like weather and soil type—that may influence organisms.

Energy enters most ecosystems as sunlight and gets converted into chemical energy by producer organisms (like plants) through photosynthesis.
This energy is passed along the food chain as organisms eat one another.
Each step or level in a food chain is called a trophic level.
Every time energy is transferred between trophic levels, some is lost as heat.

Sampling techniques are used to investigate the distribution and abundance of species in a habitat.
Techniques include quadrat sampling for plants, pitfall traps for small animals, and sweep-netting for insects.
All data collected should be handled responsibly due to ethical considerations.

Human activities cause pollution, which may have negative effects on biodiversity and cause climate change.
Pollution includes air pollution leading to acid rain, and water pollution causing eutrophication and oil spills.
Indicators species can be used to assess the level of pollution in an environment.
Human-induced climate change is causing shifts in species’ distribution and the timing of natural events.