Ecology Quizzes.docx

Ecology is the study of the interrelationship of plants and animals with each other and with their environment. An ecosystem refers to organisms and their interactions with their environment. Biosphere is all the parts of the earth where life exists. Habitat is the place where a species lives. Abiot...

Ecology is the study of the interrelationship of plants and animals with each other and with their environment. An ecosystem refers to organisms and their interactions with their environment. Biosphere is all the parts of the earth where life exists. Habitat is the place where a species lives. Abiotic Factors are non-living features of the environment. Edaphic Factors are abiotic factors relating to soil. Biotic Factors are influences of living organisms on each other. Every species has its own set of conditions that it requires. These are called environmental factors. They include abiotic and biotic factors and vary greatly depending on whether the environment is terrestrial (land) or aquatic (water). Each species has adaptations to its environment, Adaptations are the features of an organism that allow it to have a better chance of survival in its habitat. Biotic Factors - Feeding: If a species is used as food by another species, then its population will be reduced. If a species that is used as food is plentiful, then the consumer will become more numerous as it will be able to produce and feed more young. - Disease: Disease is generally caused by other living things. Disease usually reduces populations, sometimes very significantly. - Pollination: The transfer of pollen from an anther to a stigma. Carried out by insects such as bees. If bees are scarce, then pollination is not as successful and the number of seeds produced will dop, which will affect the plant population. - Nitrogen-fixing bacteria: Important in maintaining soil fertility. Found in the root nodules of leguminous plants and free-living soil. Replace nitrates used by the plants. - Decomposers: Break down the remains of dead plants and animals to the soil to be reused. Abiotic Factors - Climatic Factors: a. Light intensity has a major influence on the distribution of plants and some animals. Daisy’s only grow in areas where there is strong light exposure. Bluebells can photosynthesise in very little light and will grow only in areas with a lot of shade. b. Temperature is important in controlling the rate of chemical reactions. Temperatures vary very little in large bodies of water. Organisms living in water tend to be far less tolerant to heat changes. A 5oC change in temperature can kill a fish as it has no mechanisms to adapt to these changes. c. Exposure to the elements is another factor in coastal systems. Plants that live in the intertidal zone are exposed to large changes in their environment up to four times a day. They have many adaptations to survive the changes in its environment. - Edaphic Factors: a. pH is the measure of acidity or alkalinity of the soil. pH affects the availability of nutrients to the plants. Most plants like neutral to slightly alkaline soils. b. Mineral Content is determined by the underlying bedrock. Minerals are vital for plant growth. c. Water content is important because the minerals are obtained from the soil while they are in solution, if there is insufficient water, the soluble minerals will not be available. The plants will wilt, and photosynthesis will be reduced. Too much water can deprive the roots of oxygen and reduce growth. d. Humus is a dark organic substance made from decaying plant and animal material. It provides a good source of nutrients for plants and increases the ability of the soil to retain moisture.