Ecology Chapter 2 PDF

BAGHDAD COLLEGE Dr. JASIM MOHAMMED ALOBAIDI BIOLOGY CLASS 4th CHAPTER 2 / ECOLOGY The Scope of Ecology Ecology: (from the Greek oikos, “home,” and log...

BAGHDAD COLLEGE Dr. JASIM MOHAMMED ALOBAIDI BIOLOGY CLASS 4th CHAPTER 2 / ECOLOGY The Scope of Ecology Ecology: (from the Greek oikos, “home,” and logos, “to study”) is a branch of science that studies the interactions of living things with each other and with the environment. Q/ why today environmental problems have increased? (Or) Why ecology is taught as a science in schools? A/ Due to development in technology and industry, and because of the unwitting actions of people. For example,  The overuse of chemical substances contaminates the water and causes slow-progressing diseases in humans.  The inefficient use of soil depletes water sources and makes the soil arid. NOTE/ the levels between organisms and biosphere are included in ecology: protoplasm - cells - tissues - organs - organ systems - organisms - population - community - ecosystem – biosphere - earth - planets - solar system - galaxies – cosmos. Terms used in Ecology Ecosystem: A community together with the abiotic environment forms an ecosystem. Environment: is the place where an organism lives, The environment includes abiotic components (nonliving chemical and physical factors) such as temperature, light, water, and nutrients and biotic components (living) such as plants, animals, fungi-all the other organisms. Organismal (Individual) Ecology: A branch of ecology that studies the relationship of an individual or individuals of a species to the environment. Population ecology: The next level of organization in ecology is the population. Population: (is the smallest unit of ecology) a group of individuals of the same species living in (the same area) a particular geographic area. Q/ one population are not self-sufficient. A/ A population exists as long as it lives together with other populations and maintains its relations. Community: A group of populations living together in the same area, with abiotic factors included. Communities are self-sufficient. Q/ What is the difference between population and community? A/ 1- Population is the smallest unit of ecology, but community is bigger from population in ecology. BAGHDAD COLLEGE Dr. JASIM MOHAMMED ALOBAIDI BIOLOGY CLASS 4th 2- Population is a group of individuals of the same species living in the same area, but community is a group of populations living together in the same area. 3- One population is not self-sufficient, but Communities are self-sufficient. Biosphere: All of the places where organisms can live, from the bottom of the ocean to an altitude of 10,000 m. Habitat: The natural environment or place where an organism, population, or species lives. For instance:  Habitat of paramecium is fresh water.  Habitat of certain kind of ants is trees in the forest. Biome: The geographical area of the environment that an organism needs to live (the place where the community lives). Biomass: The dry weight of organic matter comprising a group of organisms in a particular habitat. Flora: The plant or bacterial populations living in a particular environment. Fauna: The animal populations living in a particular environment. Interaction: is a key idea in ecology. Q/ No organism are completely self-sufficient. A/ Organisms depend upon other organisms and upon the environment for survival. For example autotrophs produce food and oxygen and heterotrophs produce carbon dioxide, which is needed for autotrophs to produce food. Branches of Ecology  Global ecology.  Ecosystem ecology.  Community ecology.  Population ecology.  Physiological ecology. Ecosystem components An ecosystem (environment): is all the living and nonliving factors that surround an organism. The ecosystem includes: A- Biotic components 1. Producers: autotrophic organisms which can produce their own food. In terrestrial ecosystems, the dominant producers are green plants, while in fresh water and saltwater ecosystems, the dominant producers are algae (a kind of protist). BAGHDAD COLLEGE Dr. JASIM MOHAMMED ALOBAIDI BIOLOGY CLASS 4th 2. Consumers: are heterotrophic organisms that cannot produce their own food. Q/ List types of consumer can be identified according to their food source. A/ There are four types of consumer can be identified according to their food source.  Herbivores (also called primary consumers), such as sheep, eat plants directly.  Carnivores (secondary or tertiary consumers), such as lions, feed on other animals.  Omnivores, such as humans, feed on both plants and animals.  Decomposers are (organisms of decay): They break down detritus (nonliving organic matter) to inorganic matter which can be used again by producers. In this way materials are constantly recycled in an ecosystem. Q/ Decomposers are contributing constantly recycled of materials in an ecosystem. A/ they break down detritus (nonliving organic matter) to inorganic matter which can be used again by producers. B- A biotic Components:  Minerals:  It can be solid that form the soil.  It contains all elements and chemical compounds which are necessary for life maintenance.  Organic and non-organic materials are main components of soil.  Water:  It forms the biggest part in the ecosystem, such as: rivers, lakes and oceans.  Water is the habitat for many solvent minerals and chemicals. Q/ Water basically are the most important life source. A/ due to its percentage in living cell (more than 90% in some cells kinds).  Gases: Q/ What is the importance of gasses in ecosystem? A/ Take an important role in ecosystem, represented by  A mixture of different gasses that forms biosphere.  Mainly this mixture is formed by Nitrogen, Oxygen, CO2, water vapor and other gasses.  Although all of these gasses are important but, oxygen is the most important base that forms any ecosystem. BAGHDAD COLLEGE Dr. JASIM MOHAMMED ALOBAIDI BIOLOGY CLASS 4th  Solar energy: Q/ Solar energy clearly affect the ecosystem. (Or) Solar energy affects the density of living organism's numbers from one habitat to another. A/ this effect appears in different forms due to alternation of earth position around the sun and four season's sequence.