Biology Midterm Review PDF

BIOLOGY MIDTERM REVIEW: ecology- the scientific study of interactions among and between organisms and their physical environment. levels of organization- 1 Individual organism 2 Population 3 Community 4 Ecosystems 5 Biome 6 Biosphere population...

BIOLOGY MIDTERM REVIEW: ecology- the scientific study of interactions among and between organisms and their physical environment. levels of organization- 1 Individual organism 2 Population 3 Community 4 Ecosystems 5 Biome 6 Biosphere population- a group of individuals that belong to the same species and live in the same area. community- an assemblage of different populations that live together in a defined area. ecosystem- all the organisms that live in a place together with their physical environment. biome- a group of ecosystems that share similar climates and typical organisms. biosphere- our entire planet, with all its organisms and physical environments biotic- living; biological influences on organisms. Example: plants, animals, bacteria, fungi (mushrooms) abiotic- non living; physical components of an ecosystem. Example: sunlight, heat, precipitation, humidity, wind, soil type. primary producers (autotrophs)- the first producers of energy-rich compounds that are later used by other organisms. They make their own food through the process of photosynthesis. Example: plants, algae. consumers (heterotrophs)- organisms that rely on other organisms for energy and nutrients. Example: carnivores, scavengers, decomposers, herbivores, omnivores. carnivores- kill and eat other animals. Example: snake, dogs, cats scavengers- “natures clean up crew” animals that consume the carcasses of other animals that have already been killed. Example: king vulture. decomposers- break down/ recycle dead organism matter (nutrients). Example: bacteria, fungi How does energy flow through ecosystems? Energy floes through an ecosystem in a one-way stream, from primary producers to various consumers. Food chain- a series of steps in which organisms transfer energy by eating and being eaten. They start with Primary Producers ➡ ️ Herbivores ➡ ️ Carnivores Food web- a complex network of feeding interactions. It links all of the food chains in an ecosystem together. Ecological pyramids- show the relative amount of energy or matter contained within each trophic level in a given food chain or food web. Pyramids of energy- show the relative amount of energy available at each trophic level of a food chain or food web. Each level of the pyramid gets smaller while moving to the top because the nervy is lost to heat (most energy is at the bottom). A pyramid of biomass- illustrates the relative amount of living organisms at each trophic level. Trophic level- each step in a food chain or food web is called a trophic level. primary producers always make up the first trophic level, where the most energy is. Niche- full range of physical and biological conditions in which an organism lives and the way in which the organism obtains what it needs to survive and reproduce. (Organisms job/role in an ecosystem) Resource- any necessity in life. Example: water, nutrients, light, food, or space. How does competition shape communities? By causing species to divide resources, competition helps determine the number and kinds of species in a community and the niche each species occupies. Can organisms share the same habitat? Yes, organisms can share the same habitat but NOT share the same niche. Predator-prey relationships- when one animal (predator) captures and feeds on another animal (prey). Symbiosis- any relationship in which 2 species live closely together. Example: mutualism, parasitism, and commensalism. Mutualism (+/+)- both organisms benefit from each other. Parasitism (+/-)- parasite benefits from the host, weakening the host. Example: tapeworms living in the intestines of mammals Commensalism (+/0)- one organism benefits and the other is unaffected. Example: barnacles attaches to a whale’s skin. Ecological succession- a series of more-or-less predictable changes that occur in a community over time. Primary succession- succession that begins in an area with no remnants of an older community (no soil). Takes longer than secondary succession. Example: volcanic explosions, retreating glaciers. Pioneer species- the first species to colonize barren areas in primary succession. Example: linchen. Secondary succession- occurs in existing communities are not completely destroyed by disturbances. Proceeds faster than primary succession because soil exists. Example: wild fire, hurricane. Carrying capacity- the number of organisms that the specific environment can support. What factors determine carrying capacity? Limiting factors Renewable resources- naturally replaceable, can be produced or replaced by a healthy ecosystem. Example: water. Non-renewable resources- cannot be replaced naturally with a reasonable amount of time, natural processes cannot replenish them. Example: coal, oil, natural gas. What are the major forms of air pollution? Smog, acid rain, greenhouse gases, and particulates Acid rain- airborn acids formed because of the burning of fossil fuels which release nitrogen and sulfur compounds. Those compounds combine with water vapor, forming nitric and sulfuric acids (acid rains). Greenhouse gasses- gases that contribute or global warming/ climate change. Example: carbon dioxide, methane. Biodiversity- the total of all the genetically based variation in all organisms in the biosphere. The more biodiversity, the more stable the ecosystem. What are the most significant threats to biodiversity? Altering habitats, hunting, introducing invasive species, releasing pollutions into food webs, contributing to climate change. Invasive species- organisms introduced into new habitats that disrupts the native species and threaten biodiversity since they have no natural predators. How do we preserve biodiversity? Protect individual species, preserve habitats and ecosystems, and make sure that human neighbors of protected areas benefit from participating in conservation efforts. Ozone depletion- exposes us to more UV radiation, increasing our chances for skin cancer. Chlorofluorocarbons (CFCs)- a gas that could damage the ozone layer. What is the major cause of global warming? Increase of carbon dioxide in the atmosphere, caused by burning of fossil fuels and deforestation. How does water move through the biosphere? Water continuously moves between the oceans, the atmosphere, and land. Water vapor- a gas when they evaporate from the ocean or other bodies of water. How does water enter the atmosphere- water evaporates from the ocean or by evaporating off of the leaves of the plants (transpiration). Stages of water cycle- 1 Evaporation 2 Condensation 3 Precipitation 4 Transpiration 5 Accumulation 6 Run-off Evaporation- liquid to gas, moves from the ground or body of water to the atmosphere. Condensation-water vapor to liquid droplets in the air, results in clouds and fog. Precipitation- condensed water vapor falls to the surface, results in snow, hail, sleet. Transpiration- release of water vapor from plants and soil into the air. Accumulation- where the water accumulates; ponds, lakes, ground water. Run-off- the way water moves across the land. This water can seep into the ground, evaporate, get stored in lakes and reservoirs, or extracted by humans. What nutrient cycles does oxygen participate in? Carbon nitrogen, phosphorus cycles. Oxygen is released through photosynthesis and used in respiration. In the carbon cycle, plants 2 purposes are: producing oxygen, producing food for primary consumers. Nitrogen cycle- happens in the ground in plants. Nitrogen fixing bacteria (contained by plants)- convert nitrogen gas ammonia during the process of nitrogen fixation. Nitrogen fixation- the process of making nitrogen usable for our bodies. How does the nitrogen cycle work? 1 Nitrogen fixation occurs 2 Plants consume the nitrogen 3 Consumers eat the plant or the animal that ate the plant 4 Decomposers break, down the dead animals release nitrogen gas back into the atmosphere (denitrification) Evolution- a change over time. A process by which organisms have descended. Used to make predictions about the world. Charles Darwin- 1859, proposed the Theory of Evolution using evidence he collected while traveling the world Darwin’s scientific theory of biological evolution- explains how modern organisms evolved over long periods of time through descent from common ancestors. Artificial selection- selective breeding process where nature provides the variations, and humans select those they find useful. Example: farmers would select for breeding only trees that produced the largest fruit or cows that produced the most milk. Natural variation- differences among individuals of a species. Only occurs in sexually reproducing species. Mutations and genetic recombination- 2 process that result in variations that commonly influence the evolution of sexually reproducing species. What were the main ideas of Darwin’s theory of evolution? Overproduction, variation, competition, reproduction, natural selection. Variation- differences in traits of an individual from the group to which it belongs. Completely- struggle for existence among other organisms. High growth rates and a shortage of life’s basic needs (water, food, space) would eventually force organisms to compete for resources. Reproduction- the surviving “fit” organisms will be the only members of a species left to reproduce, their most useful traits will be passed on to the next generation. Natural selection- the process by which organisms with variations most suited to their local environment survive and leave more offspring. What was the main weakness of Darwin’s theory? His inability to explain the sources of variation he observed. Survival of the fittest- the differences in rates of survival and reproduction. Fitness- describes how well an organism survives and reproduce in its environment, fitness results from adaptation. Adaptation- refers to any structural, functional or behavioral characteristics of an organism that helps it better survive in its environment. Fossil record- fossils formed in different layers of rock with evidence of gradual change overtime. Usually found in sedimentary rock (oldest layer of rock at the bottom) Geographic distribution of Living things- descended from an ancestor with modification. Homologous body structure (comparative anatomy)- structures that are shared by related species and they have been inherited by a common ancestor, they differ in form and function but are constructed from base bones. Similarities of early development (comparative embryology)- similar patterns of embryonic development provide further evidence that organisms descended from a common ancestor. Vestigial structures- inherited from ancestors but have lost much of all their original function due to different selection pressures. Speciation- the creation of new species. Species- a group of organism that breed with one another and produce fertile offspring. Behavioral isolation- when two populations are capable of interbreeding but have differences in courtship rituals or behavior. Examples: Eastern meadowlark and western meadowlark, they don’t interbreed because they sing different songs to attract mates. Geographic isolation- when 2 populations are separated by geographic barriers. Example: rivers, mountains, other bodies of water. Temporal isolation- when 2 or more species reproduce at different times. Example: 3 types of orchid in 1 rain forest. Each species releases pollen on 1 day, because they release pollen different days, they are unlikely to reproduce with each other. Mechanical isolation- occurs when physical differences prevent successful mating between 2 population. Allopathic speciation- groups from an ancestral, population evolve into separate species because of geographical isolation. This begins when a population is divided by a geographic barrier preventing inbreeding between the two resulting populations. Sympatric speciation- groups from the same ancestral population evolve into separate species without geographical isolation. (Formation of a new species without geographic isolation). These populations share the same geographic area. Parapatric speciation- formation of a new species within the same geographical area at the parent species. Divergent evolution (adaptive radiation)- species become more different. Closely related species diversify to new habitats. EX: Modern elephant and wooly mammoth, they both share a common ancestor, yet developed into different species. Convergent evolution- different species evolve in similar ways because of a shared evolution. EX: seal and dolphin, both evolve similar traits moving through water. Coevolution- 2 species evolve in similar ways. EX: hummingbird and flower. Gradualism- species are always slowing evolving. Changes occur slow and constantly overtime. (Graph looks like one big thing of connected lines all going in different directions) Punctuated Equilibrium- long periods of no change (stability) followed by very short, fast changes in a species. (Graph looks like multiple lines going up and down)