Genes, the environment, and the organism - An Introduction to Genetic Analysis - NCBI Bookshelf
Ecology is the study of the relationships between living organisms and between those organisms and their natural environment. Ecological consultants study. Is the relationship between organisms positive, negative or neutral? abundance in the urban environment. design simple studies to answer their questions. The environment influences gene action in many ways, about which we shall learn Thus, through genes, an organism builds the orderly process that we call life Such a set of environment-phenotype relations for a given genotype is called.
The questions above are generally applied to species at the same trophic level—say, the plants in a community, or the insects that feed on the plants there, or the birds that feed on the insects there. Yet a different set of questions in community ecology involves how many trophic levels there are in a particular place and what factors limit that number.
Conservation biology seeks to understand what factors predispose species to extinction and what humans can do about preventing extinction. Species in danger of extinction are often those with the smallest geographic ranges or the smallest population sizes, but other ecological factors are also involved. Ecosystem ecology examines large-scale ecological issues, ones that often are framed in terms not of species but rather of measures such as biomass, energy flow, and nutrient cycling.
Carbon is the basis of life see carbon cycleso these questions may be framed in terms of energy.
Lesson Plans: Organisms in the Environment
How much food one has to eat each day, for instance, can be measured in terms of its dry weight or its calorie content. The same applies to measures of production for all the plants in an ecosystem or for different trophic levels of an ecosystem.
A basic question in ecosystem ecology is how much production there is and what the factors are that affect it. Not surprisingly, warm, wet places such as rainforest s produce more than extremely cold or dry places, but other factors are important. Nutrients are essential and may be in limited supply. The availability of phosphorus and nitrogen often determines productivity—it is the reason these substances are added to lawns and crops—and their availability is particularly important in aquatic systems.
On the other hand, nutrients can represent too much of a good thing. Human activity has modified global ecosystems in ways that are increasing atmospheric carbon dioxidea carbon source but also a greenhouse gas see greenhouse effectand causing excessive runoff of fertilizers into rivers and then into the oceanwhere it kills the species that live there.
Methods in ecology Because ecologists work with living systems possessing numerous variables, the scientific techniques used by physicists, chemists, mathematicians, and engineers require modification for use in ecology. Moreover, the techniques are not as easily applied in ecology, nor are the results as precise as those obtained in other sciences. It is relatively simple, for example, for a physicist to measure gain and loss of heat from metals or other inanimate objects, which possess certain constants of conductivity, expansion, surface features, and the like.
To determine the heat exchange between an animal and its environment, however, a physiological ecologist is confronted with an array of almost unquantifiable variables and with the formidable task of gathering the numerous data and analyzing them. Ecological measurements may never be as precise or subject to the same ease of analysis as measurements in physicschemistryor certain quantifiable areas of biology.
Competency Relationships Between Organisms and the Environment | BioEd Online
In spite of these problems, various aspects of the environment can be determined by physical and chemical means, ranging from simple chemical identifications and physical measurements to the use of sophisticated mechanical apparatus.
The development of biostatistics statistics applied to the analysis of biological datathe elaboration of proper experimental design, and improved sampling methods now permit a quantified statistical approach to the study of ecology. You can also find guides for most states online search for plant field guide and the name of your state.
If an outdoor excursion is not feasible, consider generating a list of plants that grow locally. Students may be able to brainstorm some species.
You can add to that list by consulting a gardening book or web site. Locate your plant hardiness zone typically shown on a color-coded map and look for plants that are recommended for that zone.
You might also invite a park naturalist, master gardener, or other person who works with plants to come in and help the class generate a list of local plants.
This experience can be modified to fit both the K-2 and grade ranges. Teachers of younger students may opt to conduct this exercise as a whole class activity, or in small groups with adult assistance. Younger students might also generate a short list of local plants — just a few species.
Students in upper elementary will be able to work more independently — either as individuals or in small groups. They should be able to generate a longer list of species. Next, research each local species and its needs in terms of temperatures, sunlight, and rainfall.
- BioEd Online
Image courtesy of mwhaling, Flickr. Once research has been completed, identify plants that grow in different environments around the world and research their needs in terms of temperature, rainfall, and sunlight. Again, the strategy for implementation will depend on the age and abilities of students in your class. Teachers of younger students might pre-select a few plants and conduct the research as a class, while older students might be assigned to a particular location or type of environment and research plants and their needs independently.
Explain In this phase, students should identify similarities and differences between the local plants and those from faraway locations.
Students might use a Venn diagram or a T-chart to record ideas and organize their thinking. Students will be most successful if they compare and contrast two species, not all the plants researched. Discuss student findings as a class. All food chains begin with producers, followed by primary consumers, secondary consumers and tertiary consumers.
Energy Flow through Ecosystems Energy flow in marine and terrestrial ecosystems is discussed in this resource from The Habitable Planet. Model Ecosystems Use this interactive module developed by McGraw Hill to learn about energy flow in forest ecosystems.
The Effect of Populations on Ecosystems The beginning teacher knows how populations and species modify and affect ecosystems. Species can affect one another and ecosystems in a variety of ways. Communities tend to become more complex over time.
This process, known as succession, leads to changes in soil, and the populations of organisms that are present. Primary succession takes place when organisms gradually inhabit a bare substrate such as rockleading to the development of soil and gradual increases in the numbers of kinds and species. Over time, as conditions change, different groups of organisms become prevalent.
Secondary succession occurs in an area where a disturbance, such as fire, has occurred. In general, early stages of succession are characterized by fast-growing or weedy species that tolerate extreme conditions, known as r-selected species.