G O 1 Biological diversity is reflected in

G. O. 1 Biological diversity is reflected in the variety of life on Earth. 1 -2 Interdependence

All organisms depend on other organisms in order to survive What organisms do YOU depend on in order for YOUR survival? You should be able to list at least 5! 1. 2. 3. 4. 5.

Interdependence Organisms within an ecosystem are connected. Many organisms are in competition. Competition: Organisms compete for the same habitat, resources (ex. Water), mates and food. Example = ? Intraspecies competition: competition between organisms of the same species. Ex: two trees of same species competing for sunlight. Interspecies competition: competition between organisms of different species. Ex: cheetah and lion competing for the same prey. How to remember? Think “intersection” is two or more roads coming together…interspecies is two or more species…

Niche A niche describes the interrelationships of a species or population in an ecosystem. It includes how a population responds to the abundance of its resources and enemies (e. g. , by growing when resources are abundant, and predators, parasites and pathogens are scarce) and how it affects those same factors (e. g. , by reducing the abundance of resources through consumption and contributing to the population growth of enemies by falling prey to them).

NICHE - Relationships of organisms Each and every species depends on many other species within an environment in order to survive and prosper. Food Chain Food Web Food Pyramid These represent different types of ongoing relationships between and among all organisms, within a particular environment.

Two Types of Niches Broad niche: – the organism has the ability to eat a number of plants or other animals as seasons and habitat change. - organisms occupying a broad niche are called Generalists and can spread over large areas. In Canada, temperature changes daily and seasonally so food supplies are not very diverse. Here there is less diversity but there are large numbers in the populations.

Narrow niche: the organism has adaptations that make it very efficient at surviving in their own environment, but no other. The organism tends to compete for one food source. Organisms occupying a narrow niche are called Specialists. Specialization allows many different species to inhabit one particular habitat but prevents the spread to a larger area. Example: In the tropics where temperatures & food supplies are relatively stable, there is an incredible diversity of species but small population numbers

NICHE - Distribution of Ecosystem Resources Resource Partitioning • is the action which enables competing species to share resources by accessing these resources in different ways.

Symbiosis two or more organisms living in a long term relationship. For example: dog tick. Tick may live on a dog for months, even years. The dog does not die but the tick receives essential nutrients from it’s blood. define mutualism, parasitism and commensalism. (page 16 -19 in your textbook)

Parasitism, Commensalism or Mutualism?