Unit A Biological Diversity PDF

Unit A Biological Diversity Key Concepts ▪ biological diversity inheritance ▪ species chromosomes, genes and DNA ▪ diversity within cell division- species includes binary ▪ habitat diversity fission an...

Unit A Biological Diversity Key Concepts ▪ biological diversity inheritance ▪ species chromosomes, genes and DNA ▪ diversity within cell division- species includes binary ▪ habitat diversity fission and ▪ niches formation of sex ▪ populations cells natural and artificial selection of genetic characteristics Section 1.0 ▪ Biological diversity is reflected in the variety of life on Earth. ▪ Ecosystems, Species, and Genetic Diversity ▪ Interdependence ▪ Variation within Species Life ▪ Planet Earth is approximately 4.6 billion years old. ▪ The emergence of life came approximately 3.6 billion years ago ▪ 1st organisms were single celled ▪ 1st multicellular animals arrived ~600 million years ago ▪ The existence of life on Earth is made possible because of: H2O + O2 + CO2 or water+ oxygen + carbon dioxide ▪ 1st life was likely photosynthetic to produce O2 ▪ The conditions on Earth haven’t been constant over time and are not constant across the planet. Life  1.1 Ecosystems, Species, and Genetic Diversity Species ▪ A species is a particular group of organisms that have the same structure and can reproduce (breed) with each other to produce fertile offspring (offspring that are able to reproduce). ▪ Narrowest group in which all the organisms have a similar set of adaptations yet there is still diversity within a species ▪ Of the 30 – 100 million possible different species of living things, there are over 1.5 million species of animals and 350 000 species of plants that have been identified by biologists. ▪ The most successful life form seems to be the insect. All Living Things ▪ are made up of cells ▪ need energy ▪ grow and develop ▪ reproduce ▪ have adaptations which suit them to the specific habitat in which they live Understanding Biological Diversity ▪ The entire collection of living organisms, each with their own unique characteristics, makes up the Earth’s biodiversity. ▪ “Biological diversity refers to the variety of species and ecosystems on the Earth and the ecological processes of which they are a part.” ▪ Also known as biodiversity ▪ Important functions and implications: ▪ most of our medicines come from nature (ex. plants, venoms etc.) and other products (rubber, cotton, food etc.) ▪ food webs and the organisms in them keep things stable and balanced; removing one can cause changes in the web ▪ biogeochemical cycles and other interactions are important for stability ▪ Understanding Biological Diversity ▪ To accurately estimate biological diversity on Earth, scientists must look at both large and small scales. ▪ At a large scale, they look at the area and location of different habitats. ▪ A technique called “remote sensing” involves analyzing photographs taken from satellites to help biologists make rapid assessments of large areas ▪ At a small scale, scientists take samples of as many species as possible to see which organisms actually live in a habitat ▪ The challenge is to get samples from sites that are hard to reach (ex. treetops) Understanding Biological Diversity ▪ Diversity index refers to the measurement of the diversity or variety of species in an area compared to the total number of organisms in the same area ▪ it is used to check the health of an ecosystem ▪ high diversity index= healthier ecosystem ▪ Ex. a jungle with many different animals would have a high diversity index ▪ Careful- a polluted lake may have just as many organisms as a natural lake BUT not as many different species therefore, it has a low diversity index and is less healthy The Three Main Components of Biodiversity are 1. Ecosystem Diversity 2. Community and Species Diversity 3. Genetic Diversity Ecosystem ▪ An ecosystem is any place on Earth in which living (biotic) things interact with other living and non-living (abiotic) things. ▪ This is more encompassing than habitat, which is simply where a species lives. ▪ Ecosystems are dynamic and constantly changing as biotic and abiotic factors interact. ▪ This includes multiple species interacting (ex. plants in a forest competing for space to grow), multiple abiotic factors interacting (ex. water cycle with carbon cycle) and multiple biotic factors interacting with abiotic factors (ex. biotic organisms breathing abiotic air and using abiotic oxygen or phosphate from soil entering roots of plants) ▪ Temperature and the amount of water have the biggest impacts on what type of ecosystems will develop in a specific region planet. Biotic ▪ Those factors in the ecosystem of LIVING origin. ▪ Could be dead as long as they were once living (metabolizing) ▪ Examples ▪ tree, deer, decaying log, human fungus Abiotic ▪ Those factors in ecosystems of NONLIVING origin. ▪ never living ▪ Examples ▪ water/humidity, atmospheric conditions, temperature, carbon dioxide (CO2) levels, weather, nitrogen (N2) levels, oxygen (O2) levels, nutrients, light, NO2/K+/NaCl in the ground, pH/acidity Ecosystem Diversity ▪ Ecosystem diversity refers to the different types of living communities and the environments (different types of ecosystems), such as marshes, lakes, streams and forests, in which organisms are found (located). ▪ Generally speaking, biodiversity in wetter and warmer ecosystems is higher than in drier and colder ones. Populations ▪ Populations are members of a species that live in a specific area and share the same resources. ▪ Within populations of organisms, there are subtle variations between individual members (ie. height, hair colour, eye colour). Traits can vary between members of a population. Therefore, there can be variations within species. Community ▪ Communities are formed when populations of different species live in the same area. Community and Species Diversity ▪ Community diversity occurs within populations of organisms living within a particular ecosystem. ▪ Species diversity occurs within individual organisms of the same species. Genetic Diversity ▪ Genetic diversity occurs within organisms at a cellular level, as it describes the variety of genetic material in all living things. ▪ If a population lacks genetic diversity, then it might not be able to survive environmental change and reproduce. ▪ Examples ▪ Banded snail - variation in shell coloring (yellow to brown) and banding on the shells (no bands to covering the whole shell) ▪ Different blood types (A, B, AB, O) Species Distribution ▪ Plant and animal species are not distributed evenly throughout the various eco-regions of the world. ▪ Most of the different species of plants and animals can be found in tropical regions and, more specifically, in the rainforests near the equator. ▪ As you move closer to the poles of the Earth, there is less biological diversity. Classifying Biological Diversity ▪ The two-name Latin naming system (binomial nomenclature) for all living things was developed by Carolus Linnaeus in the 18th century, enabling scientists around the world to refer to the same species, by the same name. ▪ This classification system was much more reliable than previous systems, because he used structure, rather than habitat. ▪ About 1.75 million species have been identified but many scientists believe that this only represents 1-2% of species on the planet. ▪ The science that classifies all these different species into their ‘natural groupings’ is called taxonomy, and its practitioners are called taxonomists. ▪ Evolution is a gradual process and species are constantly changing, even now. Therefore, the classification system has changed and improved as we learn more about life. ▪ Two words identify each organism. ▪ The first word indicates the name of the genus to which the organism belongs and the second word indicates the particular species. ▪ The genus word is capitalized but the species word is not. ▪ When typing both words are italicized. ▪ When handwriting both words are underlined. ▪ Examples coyote is Canis latrans while the Grey wolf is Canis lupus 5 Kingdom Classification System The 5 kingdoms are: ▪ Animalia (ex. animals, insects, fish, etc.) ▪ multicellular organisms dependent on other organism for food; their cells are bound by flexible membranes, and they are usually capable of locomotion ▪ Plantae (ex. plants) ▪ multicellular organism that make their own food by photosynthesis; their cells also have a rigid cell wall ▪ Fungi (ex. yeasts, moulds and mushrooms) ▪ non-photosynthetic and need to get their food from other organisms (they digest this food outside themselves and then absorb it); some are unicellular, some are multicellular ▪ Protista (ex. amoeba, paramecium, euglena) ▪ includes mostly single-celled organisms that do have a nucleus (Eukaryotes), but also some multicellular (many-celled) organisms ▪ Monera (prokaryotes ex.bacteria) ▪ single celled (unicellular) organisms that do not have a proper, membrane-bound nucleus; may live singly or in in colonies The 5 kingdom classification system can be further subdivided, based on physical characteristics, with each sub-division having its own name. 7 taxonomy/classification/hierarchical divisions are: ▪ kingdom ▪ phylum ▪ subphylum ▪ class ▪ order ▪ family ▪ genus ▪ species  Example - Cat Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Genus: Felis Species: domesticus binomial genus-species name: Felis domesticus Biomes ▪ Large areas that are characterized by its vegetation, soil, climate, and wildlife. ▪ 5 major biomes on planet Earth: 1. aquatic 2. grasslands 3. forests 4. deserts 5. tundra Most of Canada is the taiga (boreal forest) biome. Alberta has 2 biomes (taiga and grassland) Biomes Aquatic Biome - includes both freshwater and saltwater, as well as coral reefs Grassland Biome - open regions dominated by grass with warm and dry climate ▪ Tropical grasslands or savannas ▪ closer to the equator ▪ few scattered trees ▪ Temperate grasslands (prairies-tall grasses or steppes-short grasses) ▪ further from the equator ▪ no trees or shrubs Forest Biome - dominated by trees ▪ Tropical forests ▪ warm, humid, near equator ▪ Temperate forests ▪ higher latitudes ▪ more varied climate; 4 seasons ▪ Boreal forests (a.k.a taiga) ▪ higher even latitudes ▪ coldest and driest climate  Desert Biome -dry areas where rainfall is less than 50 cm/year ▪ very low biodiversity ▪ special adaptations required ▪ can be: ▪ hot and dry ▪ semiarid ▪ coastal ▪ cold Tundra Biome - extremely inhospitable conditions with lowest measured temperatures ▪ very low precipitation ▪ poor soil quality ▪ low biodiversity ▪ extreme conditions ▪ Arctic tundra ▪ high latitude ▪ contains permafrost ▪ Alpine tundra ▪ high altitude ▪ no trees Biodiversity & Biomes ▪ Biodiversity varies across each of the biomes. The conditions in each of the biomes influences the biodiversity because only certain adaptations will allow organisms to survive. Those best suited to environmental conditions will survive and reproduce in those areas. ▪ Greatest diversity ▪ aquatic, forest, grasslands ▪ relatively temperature therefore, support a great deal of plant and animal life ▪ Least diversity ▪extreme conditions ▪ requiring specialist and specific adaptations Biodiversity Under the Sea ▪ Coral reefs reflect a great diversity of species. ▪ Like tropical forests, coral reefs support many different communities of organisms surviving on a small amount of nutrients, which are very efficiently recycled. Biological Hierarchy ▪ Molecule ▪ Cell ▪ Tissue ▪ Organ ▪ Organ System ▪ Organism ▪ Population ▪ Community ▪ Ecosystem ▪ Biosphere Assignment ▪ Read textbook pages ▪ Focus: pages 1-15 ▪ Science in Action: pages 1-15 ▪ 1.1 Diversity worksheet  Assignment 1. Explain what is meant by the term biological diversity. 2. In one or two sentences explain why so many different types of organisms exist on Earth today. 3. Describe how scientists classify an organism. 4. Explain how the classification system helps us to understand how living things are different from or related to each other. 5. Summarize, in your own words, ecosystem diversity, community diversity, and genetic diversity. 6. Compare and contrast the meanings of population and community. 7. Why is there more biological diversity closer to the equator than in Canada? Give reasons for your answer.