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Unformatted text preview: Biology 6 Chapter 3 Study guide Do we really need those insects? Many of the earth’s planet species depend on insects to pollinate their flowers. Without pollinating insects, we would have very few flowers, fruits, and vegetables to enjoy. Insects that eat other insects help control the populations of at least half the species of insects we call pests. This free pest control service is an important part of earth’s natural capital. Some insects also play a key role in loosening and renewing the soil that supports terrestrial plant life. Although insects do not need humans, we and most other land organisms needs insects. Have you thanked the insects today? No Cells vs. genes vs. chromosomes? Cells – the smallest and most fundamental structural and functional units of life. Cell theory; idea that all living things are composed of cells. Genes – consists of certain sequences of nucleotides found within a DNA molecule that contains instructions, called genetic information, for making specific proteins. These coded units of genetic information are passed on from parents to offspring during reproduction. Chromosome – a single DNA molecule, together with a number of proteins. Each chromosome typically contains thousands of genes. What is ecology? Ecology (from the greek words oikos meaning “house” and logos , meaning “study of”) is the study of how organisms interact with their living environment of other organisms and their nonliving environment of soil, water, other forms of matter, and energy mostly from the sun. Which species rules the world? What is a species? Humans, Homo sapiens (humans) rule the world. A species is a group of similar organisms that generally resemble one another in their appearance, behavior, chemistry, and genetic makeup. For sexually reproducing organisms, a species is a set of individuals who can mate and produce fertile offspring. Populations – a group of individuals of the same species living in a particular place at the same time. Examples: channel catfish in a pond, white oak trees in a forest, people in a country, etc. Community (biological community) – consists of all the populations of different species living in a particular area. Example: a population of catfish in a pond usually share the pond with other fish species, and with planets, insects, ducks, and many others species which makes up the biological community. Ecosystems: a community of different species interacting with one another and with their nonliving environment of soil, water, other forms of matter, and energy, mostly from the sun....
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- Fall '08
- Biology, Water vapor, liquid water