Unit 4 Test Review

What are biodiversity hotspots?

A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction from humans. The term biodiversity hotspot specifically refers to 25 biologically rich areas around the world that have lost at least 70 percent of their original habitat. To qualify as a biodiversity hotspot on Myers 2000 edition of the hotspot-map, a region must meet two strict criteria: it must contain at least 0.5% or 1,500 species of vascular plants as endemics, and it has to have lost at least 70% of its primary vegetation.

What is a biome?

A biome is a large terrestrial region characterized by similar climate, soil, and plants and animals.

What is the difference between a native specie, an introduced specie, and an invasive specie?

A native specie is a plant or animal naturally found in a region - it has naturally adapted to the soils and climate of a region over millions of years. Introduced species is a plant or animal not native to an area. Often introduced species will die in an area without extra water, nutrition, fertilizers, ect. Invasive Species is species likely to cause economic or environmental harm.

What is the difference between allopatric and sympatric speciation?

Allopatric speciation is speciation that occurs when biological populations of the same species become vicariant, or isolated from each other to an extent that prevents or interferes with genetic interchange. Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region.

What is artificial selection?

Artificial selection is the intentional breeding of plants or animals. It is a technique used when breeding domesticated animals, such as dogs, pigeons or cattle. Some of these animals will have traits that a breeder will want to preserve.

How can invasive species be controlled?

Biological Control (or biocontrol) is another organism is introduced to control/kill invasive. Control means not complete eradication, but reducing species to economically or environmentally manageable levels There has been some success in controlling some invasives, and insects and weeds have seen the most success. Often introduced biocontrol organisms will feed on native species when the invasives have been eradicated, or sometimes if they find the native species more tasty. As biocontrol science has become better, scientists look for organisms that eat only the target organism.

Describe three characteristics of wetlands (include the three types of wetlands)

Bogs are waterlogged peatlands in old lake basins or depressions in the landscape. Almost all water in bogs comes from rainfall. Bogs have specialised and unique flora that have evolved in their nutrient-poor and acidic conditions, including for example the carnivorous pitcher plant. As bogs are unsuitable for agriculture, forestry or development they offer an undisturbed habitat for a wide range of species, including moose, black bear, lynx, snowshoe hare and mink. Marshes are one of the broadest categories of wetlands and in general harbour the greatest biological diversity. Marshes form in depressions in the landscape, as fringes around lakes, and along slow-flowing streams and rivers. Marshes are dominated by floating-leafed plants like water lillies and duckweed. Estuaries are the area where rivers meet the sea and water changes from fresh to salt can offer an extremely rich mix of biodiversity. These wetlands include deltas, tidal mudflats and salt marshes. Mudflats and seagrass beds in particular provide a rich diet for many species of insects, birds, fish, turtles and other species.

What is the difference between bottleneck speciation, geographic isolation, and reproductive isolation?

Bottleneck speciation is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, or droughts) or human activities (such as genocide). Such events can reduce the variation in the gene pool of a population. Geographic isolation is a term that refers to a population of animals, plants, or other organisms that are separated from exchanging genetic material with other organisms of the same species. Typically geographic isolation is the result of an accident or coincidence. Reproductive isolation refers to the situation where different species may live in the same area, but properties of individuals prevent them from interbreeding. The things which stop species or groups of organisms reproducing sexually are called isolating mechanisms.

Describe chaparral biome

Chaparral biomes are found on coasts with maritime climates (moderate temperatures, long winter rainy season, prevailing winds coming from oceans). Also called temperate shrub land, vegetation consists of dense shrubs or low growing trees with leathery leaves. Fire is a normal part of this ecosystem - during the hot dry summers fires are sparked by thunderstorms and spread quickly. Many chaparral plants only sprout or drop their seeds after a fire. Many humans live in this biome because the climate is so nice, but summer fires and the resulting spring mudslides are a constant worry.

What determines the type of biome in a region?

Climate is made of both temperature and precipitation, and both are important for determining the type of biome that is found in a region.

How is a coral reef built? Describe it

Coral reefs begin to form when free-swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents. As the corals grow and expand, reefs take on one of three major characteristic structures —fringing, barrier or atoll.

What is ecosystem diversity?

Ecosystem diversity refers to the variety of ecosystems in a given place. Within any broader landscape there is a mosaic of interconnected ecosystems. To conserve biodiversity, conservation at the landscape level is critical.

What is the difference between extinction and extirpation?

Extirpation is when a species disappears from part of its former range, while extinction means that it has disappeared everywhere.

Name and describe 3 examples of invasive species.

Fire ants were introduced accidentally - in the 1930s, Argentinean fire ants arrived on shipments of lumber and coffee to the port of Mobile, Alabama. When they arrive in an area, they kill off 90% of the native ant population, and kill deer fawns, birds, livestock, pets, and at least 80 people who are allergic to their venom. Fire ants cause an estimated $68,000 damage an hour to crops and phone/power lines. Kudzu, sometimes called the plant that ate the south, was introduced deliberately in the 1930s from Japan to help control soil erosion in the southeastern US. Kudzu grows over a foot a day, and is estimated to cover 150,000 acres a year. Kudzu engulfs and kills trees and vegetation, and is very hard to eradicate. In 1986, the larvae of the zebra mussel arrived in ballast water discharged from a European ship near Detroit, Michigan.The thumbnail-sized mollusk reproduces rapidly and has no natural enemies in the great lakes.They have displaced other mussel species and depleted the food supply of other native species.

What is genetic diversity?

Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary.

What does HIPPCO stand for? Describe each

HIPPCO stands for Habitat destruction-Invasive Species- Population growth- Pollution- Climate Change- Overexploitation. Habitat destruction- -Farming simplifies communities -Grazing modifies the grassland structure and species composition -Clearing forests removes resources organisms need -Hydroelectric dams turn rivers into reservoirs upstream -Urbanization and suburban sprawl reduce natural communities -A few species (i.e., pigeons, rats) benefit from changing habitats Invasive species- They create billions of dollars in damage. Island species are especially vulnerable. They have no real predators or parasites or even compeitiors. Population growth is very high in Earth, and there is not enough resources in the world to sustain the population around 2050. The pollution harms many organisms. Air pollution degrades the environment. Water pollution affects fish and amphibians. The damage to wildlife can be severe. Climate change will have major and unpredictable effects on the world's water systems, including an increase in floods and droughts. Extremes in droughts and flooding will become more common, causing displacement and conflict. Less fresh water means less agriculture, food and income. Overharvesting is one of five primary activities threatening global biodiversity; others include pollution, introduced species, habitat fragmentation, and habitat destruction. Aquatic species are especially threatened by overharvesting, due to a situation known as the tragedy of the commons.

What are some introduced species that have been beneficial to the US?

Introduced species such as corn, wheat, rice, cattle, poultry, and other livestock provide more than 98% of the US food supply.

What is latitudinal gradient? Why is there a latitudinal gradient?

It is the increase in species density or biodiversity that occurs from the poles to the tropics. There is a latitudinal gradient because Climate stability, high plant productivity, and no glaciations, and tropical biomes support more species and show more species evenness, therefore diversity habitats increase species diversity!

What are the four zones of a lake or pond? Describe them

Lakes and ponds are made up of zones, each with its own challenges. The littoral zone is the area closest to the shore where light reaches all the way to the bottom. Plants rooted to the bottom and algae live here. Animals may include tiny crustaceans, flatworms, insect larvae, snails, frogs, fish, and turtles. The limnetic zone is the layer of open water where photosynthesis can occur. The light decreases the deeper you go until a depth is reached where the rate of photosynthesis becomes equal to the rate of respiration. This zone is not as clear and is a more prominent feature of lakes than of ponds. Aquatic life is dominated by planktonic algae, zooplankton, swimming insects and fish. Very deep lakes have an area known as the profundal zone where light does not reach. This zone is inhabited by organisms that are either attached to or crawl along the sediments at the bottom of the lake. The sediments support a large population of bacteria and fungi. The decomposers break down the organic matter and release inorganic nutrients.

Describe mountainous biome

Mountains or steep/high lands cover about 1/4th of the world's surface. Going up in elevation changes biomes in a similar way to going up in latitude. As you go up mountains, you will see first coniferous forest, then tundra. Tundra found in mountains is called alpine tundra, while tundra found at high latitudes is called arctic tundra. Because of the steep slopes, mountain soil is very easily eroded. Mountains play important roles in Earth's climate (rain shadow effects) and snow and ice on their tops increases earth's albedo (ability to reflect instead of absorb heat). Mountains are very important in the water cycle as well - they store water as ice and snow in the winter, and release it to rivers in the spring and summer. About 1.2 billion people live in mountain ranges or on their edges, and 4 billion people depend on mountain systems for some or all of their water.

Identify and describe the four types of random processes that also drive evolution

Mutation is a the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes. Genetic drift is the variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce. The bottleneck effect occurs when there is a disaster of some sort that reduces a population to a small handful, which rarely represents the actual genetic makeup of the initial population. This leaves smaller variation among the surviving individuals. In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population.

What is the difference between phenotype and genotype?

Phenotype is the organism observable trait such as skin color and genotype is the genetic makeup of an organism's cell.

What is the difference between richness, eveness, and supspecies?

Richness is variety of species, measured by the number of different species contained in a community. Evenness is the degree to which comparative numbers of individuals of each of the species present in a community are similar. Subspecies is a taxonomic category that ranks below species, usually a fairly permanent geographically isolated race.

Describe saltmarshes

Salt marshes are coastal wetlands that are flooded and drained by salt water brought in by the tides. They are marshy because the soil may be composed of deep mud and peat. Peat is made of decomposing plant matter that is often several feet thick. Peat is waterlogged, root-filled, and very spongy.

What is species diversity?

Species diversity is a measure of the diversity within an ecological community that incorporates both species richness (the number of species in a community) and the evenness of species' abundances. Species diversity is one component of the concept of biodiversity.

Describe three zones of the open ocean

Sunlit Zone is the top layer, nearest to the surface. It is also called the euphotic zone. Here there is enough light penetrating the water to support photosynthesis. Because photosynthesis occurs here, more than 90 percent of all marine life lives in the sunlit zone. The Twilight Zone is where only a small amount of light can penetrate the water at this depth. As the water becomes deeper, the pressure increase, too. Plants do not grow here. Only animals that have adapted to little light survive. Midnight Zone is that ninety percent of the ocean is in the midnight zone. It is entirely dark—there is no light. The water pressure is extreme. The temperature is near freezing. The midnight zone is also called the aphotic zone.

Describe each biome - major characteristics, animals, plants, temperature, precipitation, and location around the globe

Taiga or Boreal forest is a biome characterized by coniferous forests consisting mostly of pines, spruces and larches. Taiga is the world's largest land biome, and makes up 29% of the world's forest cover. The areas are located in Northern Canada, Europe, and Asia. The taiga is the terrestrial biome with the lowest annual average temperatures after the tundra and permanent ice caps. Extreme winter minimums in the northern taiga are typically lower than those of the tundra. The lowest reliably recorded temperatures in the Northern Hemisphere were recorded in the taiga of northeastern Russia. The taiga or boreal forest has a subarctic climate with very large temperature range between seasons, but the long and cold winter is the dominant feature. Temperate deciduous forests grow in areas that have great seasonal change - long warm summers with cold winters with several months of freezing temperatures. Precipitation is abundant and spread pretty evenly throughout the year. Deciduous trees such as maple, oak, hickory, and beech survive the winters by dropping their leaves in the fall. Because these trees drop so many leaves each year, and decomposition is relatively slow, this ecosystem accumulates a thick layer of leaf litter. Leaf litter is nutrient rich and forms a thick, excellent layer of soil. They are mostly located in Europe Asia, America, and Canada. Tropical Rainforests are found in hot, tropical climates around the equator that never get below freezing. Rainforest climates are characterized by hot humid weather, with very frequent (if not daily rain). Tropical rainforests have very high NPP - although rainforests cover only about 2% of the planet, it is estimated they contain about half of the plant and animal species on Earth. There are many specialized niches and distinct layers in the rainforest - allowing much speciation to occur. Cold grassland is called arctic tundra. During most of the year these treeless plains are bitterly cold, swept by frigid winds, and covered by ice and snow. Most precipitation falls as snow. A thick spongy mat of low growing grasses, mosses, and tiny shrubs characterize the biome. Most growth happens during a 7 to 9 week summer. Because tundra is so cold, permafrost forms. Permafrost is soil that is frozen more than 2 consecutive years. Temperate grasslands are called prairies. Prairies are characterized by uneven rains (no rainy/dry seasons), hot summers, and freezing winters. The aboveground portions of prairie grasses die back each year in the winter and decompose, producing thick, rich soils. Prairies are found in the Midwest and in southern Canada (Alberta/Saskatchewan). In Ukraine and Russia temperate grasslands are known as steppes, and in Argentina and Uruguay they are know as pampas. In South Africa temperate grasslands are called veldts. Tropical grassland is called a savanna. A savannah is always around 20 C - it never gets below freezing and has a pretty stable warm temperature. . Savannas cover about half of Africa, and large areas of Australia, South America, and India but predominantly in Africa. Most savanna grass grows in clumps interspersed with patches of bare ground. Savannas have a wet and dry season, and while mostly grass do have some scattered trees such as acacia. Savannas support lots of different species of hoofed herbivores (zebras, gazelles, giraffes etc) that migrate seasonally and spatially partition resources. Cold deserts, such as the Gobi in Mongolia, only get above freezing for 6 or 7 months of the year. Antarctica is considered a cold desert (due to lack of rainfall). Also, it is a desert that has snow in the winter instead of just dropping a few degrees in temperature like they would in a Hot and Dry Desert. It never gets warm enough for plants to grow. Just maybe a few grasses and mosses. The animals in Cold Deserts also have to burrow but in this case to keep warm, not cool. Temperate deserts have high summertime temperatures, but have several months of freezing weather in the winter. Temperate deserts also tend to get a bit more rain than hot deserts. . Temperate deserts have the plants traditionally associated with deserts - cacti, agave, and other succulents. The Mojave desert in California is an example of a temperate desert. Hot/Tropical deserts have very few actual plants (none of the cacti/agave/succulents traditionally associated with deserts). Hot deserts have hard, wind-blown surfaces with lots of rocks. The sand usually has a hard crust, which can be broken with grazing and SUV travel. Dust storms are common, especially if the hard sand crust is broken by human or animal activity.

What is the red list?

The Red List is a list of endangered species or species facing high risk of extinction (in 2007, the list included 16,306 species, 60% higher than the number listed in 1995)

Describe biotic and abiotic factors of streams and rivers

The abiotic factors can include, sediments, the organic matter which settle to the bottom, and fast-moving streams and rivers have turbulent water called rapids, where water and air are mixed together. The biotic factors may include, plants, algae, insect larvae, and crustaceans, such as crayfish.

Describe the 12 characteristics of species that are vulnerable to extinction.

The characteristics are: Species heading toward extinction are classified as either endangered or threatened An Endangered species has so few individual survivors that the species could soon become extinct over all or most of its natural range A threatened species is still abundant in its natural range but, because of declining numbers, is likely to become endangered in the near future Low reproductive rate (K stratigist - 1 or two offspring, long gestation/rearing period). Examples: Blue whale, rhino Specialized niche - blue whale, giant panda Narrow distribution - elephant seal, desert pupfish Feeds at high trophic level - bengal tiger, bald eagle, grizzly bear Fixed migratory patterns - whooping crane, sea turtles Rare - african violet, some orchids Commercially valuable - snow leopard, tiger, elephant, rhinoceros, rare plants and birds Large territories - California condor, grizzly bear, Florida panther Some organisms also have behavioral patterns that can put them at risk - The Carolina parakeet nested in large flocks that made them easy to kill, Florida Key deer are "nicotine addicts" that get killed because they forage for cigarette butts along highways.

Describe a population with high and low genetic diversity.

The greater the genetic diversity within a species, the greater that species' chances of long-term survival Populations with low genetic diversity are vulnerable to environmental change, disease and INBREEDING DEPRESSION (genetically similar parents mate and produce inferior offspring)

What is an intertidal zone?

The intertidal zone, also known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area that is above water at low tide and under water at high tide (in other words, the area between tide marks).

What is the relationship between natural selection and fitness?

The relationship between natural selection and fitness is that individuals that display fitness - that are best suited to the environment - are most likely to survive, reproduce, and pass their genes on to the next generation. Natural selection takes out those that are not a good fit or aren't as well-adapted to the environment.

List the two broad categories of aquatic biomes and list three examples of each.

The two broad categories are freshwater and marine. Three examples for freshwater are: streams, rivers and lakes. Three example for marine are: estuaries, coral reefs, and the open ocean.

What are the laws protecting biodiversity?

They are: ESA-The Endangered Species Act of 1973 (ESA) was signed on December 28, 1973, and provides for the conservation of species that are endangered or threatened throughout all or a significant portion of their range, and the conservation of the ecosystems on which they depend. CITES-CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals. Its aim is to ensure that international trade in specimens of wild animals and plants does not threaten the survival of the species in the wild, and it accords varying degrees of protection to more than 35,000 species of animals and plants.

What are the five points of natural selection?

They are: Individuals produce an excess of offspring. Not all offspring can survive. Individuals differ in their traits. Differences in traits can be passed on from parents to offspring. Differences in traits are associated with differences in the ability to survive and reproduce.

What are the 9 major terrestrial biomes found on the planet? (make sure to learn them using the chart)

They are: cold forest(taiga/boreal), Temperate forest, Hot/Tropical forest, cold grassland(Tundra), Temperate grassland(prairie), Hot/Tropical Grassland(Savanna), cold desert, temperate desert, hot desert.