Bio Exam 3 Review
Bio Exam 3 Review BIO 1421
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BIOL 3000 - 002
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This 11 page Study Guide was uploaded by Dishali Patel on Monday November 16, 2015. The Study Guide belongs to BIO 1421 at DCH Regional Medical Center taught by Dr. Davenport in Fall 2015. Since its upload, it has received 107 views. For similar materials see Modern Biology II in Biology at DCH Regional Medical Center.
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Date Created: 11/16/15
BIO 1421- Exam 3 Review -Below are the topics that you can expect to find on the exam. You will never need to memorize dates or specific examples (e.g. eribulin or cycads). Part 10: 1) Plant characteristics a) Plants exist nearly everywhere i) Form the basis for complex food webs& provide diverse habitats for all other organisms b) Plants are autotrophic i) This means they are “self-feeding,” undergoing photosynthesis (1) Photosynthesis = process of capturing sunlight and storing it as energy in a sugar molecule c) Plants are multicellular i) You can have cells that specialize in functions like leaf cells, flower pedal cells, etc d) Plants are immobile. i) Plants are anchored in place at their bases and unable to move from one place to another on their own e) Most plants reproduce sexually and some asexually i) Some plants can make offshoots, giving rise to identical offspring: asexual reproduction ii) Most plants reproduce sexually (1) Gametes ( sperm and egg) fuse together to make an embryo (2) Self pollenate= sexual reproduction f) Plants’ unique life cycle: alternation of generation i) Plants exhibit alternation of generations. 2) Alternation of generations (sporophyte, gametophyte, embryo, haploid, diploid…) a) Alternation of generations: a multucellular diploid generation alternates with a multicellular haploid generation b) Full plant = sporophyte i) Diploid (2 sets of genes) c) Sporophyte produces spores through meiosis i) Spores are haploid (1 set of genes) (1) Sometimes called pollen d) Each spore grows into a gametophyte i) Made of only a few cells ii) Not a full plant iii) Gametophytes are haploid (1 set of genes) e) Gametophytes produce gametes (eggs and sperm) which are haploid i) A sperm can then fertilize an egg f) A fertilized egg develops into an embryo. i) Embryos are diploid (2 sets of genes: 1 from egg and 1 from sperm) ii) Embryos often grow on the gametophyte, which protects and nourishes them iii) Plant embryos sometimes are called seeds g) The embryo (seed) develops and grows into a full plant i) The cycle can then start again 3) Plants & other organisms/environment: 7 positives a) Plants provide food for animals, fungi, and other heterotrophic organisms i) Energy moves 1-way coming from the sun to Earth: plants capture this energy (1) Organisms eat plants (or eat other organisms that eat plants) to gain the energy and stay alive b) Plants maintain the atmosphere i) Through the process of photosynthesis, plants: pull CO2 from the atmosphere, preventing the planet from getting too hot for living things ii) Release O2 into the atmosphere allowing for animals and other organisms to breathe c) Plants build and maintain the soil i) Dead plant material is decomposed into organic matter, adding nutrients that make soil more fertile ii) The roots of living plants hold soil together, preventing erosion by wind and water. (1) Erosion= poor growing conditions and can lead to barren land – more and more common with increased deforestation occurring d) Plants keep water in ecosystems. i) They absorb and store water from the soil and release it into the surrounding environment slowly (1) Prevents immediate evaporation, which causes severe water loss and drought in ecosystems (2) Slows the rate and amount of water runoff and flooding e) Plants provide shelter and homes for many organisms. f) Plants provide important medicines i) Ex: taxol, an important cancer drug, came from yew trees ii) Aspirin, used for fever, inflammation, etc. came from willow trees. g) Plants provide useful materials for fuel and other commercial goods i) Fuel, twine, canvas, clothing, pigments, alcohol, cleansers, oils, cosmetics, etc. 4) Major groups: nonvascular & vascular, characteristics of each st a) 1 big evolustonary split: nonvascular vs. vascular i) The 1 plants were nonvascular (1) No way to conduct water or nutrients around plant: must rely on slow diffusion to distribute water and other nutrients (2) Requires a small size and moist environment (3) No seeds: sperm and egg must meet in water (4) Since nonvascular plants must remain moist and reproduce in water, they straddle the boundary between aquatic and terrestrial life (5) Some species today are nonvascular ii) Vascular plants (1) Have tube-shaped conducting cells ( like blood vessels) (a) Provide support and transport water and nutrients throughout plant (2) Allows for a larger size and movement a bit further away from water (a) If the roots are in water, vascular plants can still live. 5) Seedednds. seedless, characteristics of each a) 2 big evolutionary split: vascular seedless vs. seeded plants i) Vascular seedless plants (1) Have NO SEEDS, so they still require sperm and egg to meet in water (2) Some stay near water sources and some have moved further away but must have time reproduction with heavy rains ii) Vascular seeded plants (1) Aided by 2 important adaptations: POLLEN AND SEEDS (2) Pollen= tiny grains for reproduction (a) Dispersed by wind or pollinators (birds, insects) (b) Eliminates the need for sperm to swim to the egg, so they can live and reproduce on dry land (3) Sperm and egg fuse to make an embryo, which is the seed (a) Seeds protect the embryo as it grows and provides it with nourishment (i) Comes in many shapes and sizes 6) Gymnosperms vs. angiosperms, characteristics of each a) 3 big evolutionary split: gymno vs. angiosperm i) Gymnosperms= vascular seeded plants that do NOT have flowers or fruits (1) Examples: cycads, Ginkgo biloba, pine and Ephedra ii) Angiosperms= vascular seeded plants WITH flowers and fruits (1) Most diverse and widespread of all plants (a) This is what we see when we look around outside (2) Flowers= reproductive structures in which gametophytes are formed (a) Evolution of angiosperms exploded when gymnosperm ancestors formed an association with animal pollinators (i) Animals benefited by eating protein-rich pollen (ii) Plants benefited by using animals as pollinators (increase plant reproduction and gene flow) (3) Fruits: contain developing seeds (a) Edible fruits entice animals to eat them: seeds pass through the digestive tract unharmed (b) Burr fruits cling to animal fur (c) Winged fruits are carried through the air (i) All increase seed/embryo dispersal NOT specific plant examples Should be able to identify the group a plant is in from a description of it Part 11: 1) Animal characteristics a) Animals are multicellular i) Blood cells, skin cells, muscle cells, etc. all carry out different functions for animals b) Animals are motile i) All can move at some point in their life cycle (1) Some are stationary as adults (like barnacles and sponges) but were still motile as juveniles c) Animals are heterotrophic i) More specifically, they eat (once) living organisms d) Animals reproduce sexually (with very few exceptions) i) Gametes (sperm and egg) fuse together to make new, genetically diverse offspring e) Animals do not have cell walls i) Unlike prokaryotes, protists, fungi, and plants, animals do not have a cell wall (1) Animal cells can take more variable shapes because they are not encased inside a hard cell wall (a) There are over 200 different types of cells in human animals 2) Major branches in evolutionary history: tissues, symmetry, body development, & growth a) Does the animal have tissues? i) Tissues= group of similar cells with a specific function like a muscle or bone (1) Sponges = only modern animals that lack tissues b) If it has tissues, does it have radial or bilateral symmetry? (1) Animals with radial symmetry can be divided into equal halves by any plane through the center (2) Most abundant radial phyla= Cnidarians (a) Includes, jellyfish, coral, and sea anemones (3) Animals with bilateral symmetry can be divided into mirror-image halves only along 1 plane that runs down the midline (a) Matching right and left halves (b) Any animal with a head c) If bilateral, does it develop front to back or back to front? i) Animals that develop front to back = protostomes (1) Thought of as front to back or mouth first because the mouth arises from the 1 st nd opening of embryoand the anus arises from the 2 opening ii) Animals that develop back to front = deuterstomes (mouth second) (1) Chordates= deuterostomes and only phylum with vertebrates (animals with backbone) (a) Includes all mammals, birds, reptiles, amphibians, and fish d) If front to back, (protostome), does it grow continuously or grow by molting? i) Animals that molt shed their exoskeleton (hard outer layer) and replace it with a bigger one (1) Largest molting phylum= arthropods, which includes insects, crabs, lobsters, spiders, ticks, millipedes 3) Major phyla & their branches: sponges, cnidarians, chordates, arthropods, mollusks i) Should be able to recognize what phyla an animal is in (5 phyla talked about) from a description 4) Invertebrates vs. vertebrates a) 96% of all discovered animal species = invertebrates (no backbone) i) E.g. insects, crabs, snails, clams, octopi, starfish, worms, etc. b) Every animal phylum contains invertebrates i) Only 1 phylum contains vertebrates (animals with a backbone) (1) Chordates= phylum containing all vertebrates and also some invertebrates 5) Animals & other organisms/environment: 4 positives, 3 negatives a) 4 POSITIVES i) Invertebrates provide food for many other animals and some plants. ii) Some invertebrates act as pollinators (1) Pollinators aid in plant reproduction, ensuring plant presence and evolution within ecosystems (benefiting all living things) (2) Pollinators include bees, ants, butterflies, moths, beetles, etc. (a) Some vertebrates are pollinators too: some birds, bats, monkeys, rodents, and even some reptiles. iii) Some invertebrates act as decomposers (1) Remember: decomposers are important for recycling minerals, nutrients and energy on Earth. iv) Some invertebrates are even used in medicine (1) Leeches are used in surgery to remove excess blood and promote blood flow (2) Blowfly maggots can rid wounds of dead tissue that interferes with healing or causes infection (3) Eribulin is a chemical drug derived from sponges that is used to treat breast cancer b) 3 NEGATIVES i) Some invertebrates are parasites (1) Hookworm larvae bore into human feet and travel to the intestine, where they cause continuous bleeding (2) Trichinella worms infect people who eat improperly cooked infected pork; their larvae invades blood vessels and muscles, causing bleeding and muscle damage. (3) Heartworms can be transmitted to cats and dogs by the bite of an infected mosquito. ii) Some invertebrates are parasites (1) Tapeworms can infect people who eat improperly cooked beef, pork, or fish that has been infected by the worms iii) Some invertebrates spread disease (1) Ticks can spread Lyme disease (a) Causes fever, fatigue, flu-like symptoms and can lead to chronic and more severe problems iv) Some invertebrates are poisonous (1) Some arachnids, such as spiders and scorpions, inject paralyzing venom into prey. 6) Chordates: 4 key features a) Notochord i) A rod of tissue extending from the head to the tail (1) Simpler chordates retain the notochord throughout life (2) In more complex chordates, the notochord in early embryos is replaced by a backbone b) Nerve cord i) Nerve cord that extends along the animal’s back (its dorsal side) (1) In vertebrates, the nerve cord eventually forms the spinal cord and brain c) Gill slits i) Slits through which water is passed in order to breathe and feed. (1) In many chordates (including humans), the slits disappear as the animal develops d) Tail i) Tail that extends beyond the posterior (back) end of the digestive system (1) Some vertebrates (including humans) have a tail only briefly, during embryonic development 7) Major groups of chordates, their adaptations & the advantages of each adaptation i) Lancelets & tunicates: invertebrates with only the basic chordate characteristics (1) No skulls, backbones, or jaws, etc. (2) Both marine animals ii) hagfishes: currently living animals with a skull but no backbone (invertebrates) (1) no jaws, limbs, etc. (2) advantage: protects the brain ST (3) 1 MAJOR ADAPTATION WITHIN THE CHORDATES= SKULL iii) Lampreys: currently living animals with a backbone but no other vertebrate adaptations (1) Advantage: expands range of motion (2) No jaws, limbs, etc. (3) 2nd MAJOR ADAPTATION WITHIN CHORDATES= BACKBONE iv) cartilaginous fishes: currently living group with jaws and cartilage but no bones or limbs (1) e.g. sharks and rays (2) aRDantage: increased feeding options (3) 3 MAJOR ADAPTATION WITHIN CHORDATES = JAWS v) bony fishes: currently living groupw tih bones but no limbs or lungs (1) Most abundant of vertebrates: fish, seahorses, eels, etc. (2) Advantage: stronger and less brittle than cartilage- allow for bigger, stronger animals that can support their weight better (3) 4TH MAJOR ADAPTATION WITHIN CHORDATES= BONES vi) Amphibians: have limbs and decent lungs (1) skin must be kept moist to avoid desiccation when out of water st (2) 1 to be able to live on land but still have aquatic egg or larval stages (3) Includes frogs, toads, and salamanders (4) “Amphibian” is Greek for “double life” (a) Begin life adapted to water (i) E.g. tadpoles have gills (b) Mature into semi-terrestrial adults with lungs (i) Adults respire through lungs and moist skin (5) 5TH MAJOR ADAPTATION WITHIN CHORDATES = LIMBS AND EARLY LUNGS (a) Advantage: limbs allow for movement on land AND early lungs allowed for time spent on land, where food was abundant and allowed an animal to escape aquatic predators. vii) Reptiles: were the 1 to live their full lives on land (1) Reptiles include lizards, snakes, alligators, turtles, crocodiles, & birds. (2) Good lungs and waterproof eggs allowed life on land (3) Also have tough, scaly skin to protect the body and prevent water loss (4) 6TH MAJOR ADAPTATION WITHIN CHORDATES= GOOD LUNGS AND WATERPROOF EGGS (a) Advantage: both allow animals to live fully on land (i) Waterproof eggs require internal fertilization: male deposits sperm into the female’s body (ii) Once egg is fertilized, the waterproof shell is formed, encasing the embryo and keeping it from drying out viii) Birds: a distinctive group of reptiles (1) Distinguished from other reptiles by feathers, : highly specialized reptilian body scales (2) Modern birds retain scales on their legs, left over shared ancestry with older reptiles (3) Most birds are adapted for flight (a) Feathers provide life and control as well as insulation (b) Hollow bones reduce the weight of the skleteon (c) Birds are warm-blooded (endothermic), unlike all other reptiles, which are cold-blooded (exothermic). ix) Mammals: vertebrates with mammary glands (1) Mammals are subdivided into 3 groups: monotremes, marsupials, placental mammals (2) 7TH MAJOR ADAPTATION WITHIN CHORDATES = HAIR AND MAMMARY GLANDS (a) Advantage: hair protects and insulates – mammals are warm-blooded (endothermic) (b) Advantage: mammary glands produce milk that nourishes young 8) 3 groups mammals & their characteristics i) Monotremes: egg-laying mammals (1) Group includes on a few species: the platypus and a few species of spiny anteater (echnidas) (a) All are found only in Australia and New Guinea (2) Monotremes lay eggs rather than giving birth to live young (a) Newly hatched young are nourished from milk secreted by mammary glands ii) Marsupials: (especially common in Australia) (1) Species include the opossums, koalas, kangaroos, wallabies, wombats, & the Tasmania devil (2) In marsupials, embryos begin development inside a uterus (no shelled egg) (a) Young are born at a very immature stage and must crawl to a nipple to complete development (b) In most, post-birth development is completed in a protective pouch iii) Placental mammals: (1) Inhabit land, air, and sea (a) 1 mammals evolved on land but some re-entered the water (whales, otters, dolphins, etc.) (2) Highly diverse: includes bats, moles, whales, monkeys, cheetahs, seals, humans, etc. (3) Most mammal species are placental mammals (a) The uterus contains a placenta that provides gas, nutrient, and waste exchange between parent and embryo (b) In placental mammals, young are retained in the uterus for their entire embryonic development Should be able to recognize the type of chordate (8 groups & 3 types mammals) from a description Part 12: 1) Ecology, population, community, ecosystem a) Ecology: branch of biology that studies the interactions between organisms and their environments i) Ecologists study the distribution and abundance of organisms (1) Where are they found? What are they like? How many are there and how do the numbers change? How do they thrive? b) Population: all the members of a particular species that live within an area c) Community: a group of several living populations interacting with each other d) Ecosystem: all the living and non-living components in an area 2) Things that affect population size a) Births and deaths always affect population size i) In populations that do not include all members of species: migration (immigration and emigration) affects population size ii) 2 opposing forces affect birth and death rates, and thus affect population growth (1) Biotic potential (2) Environmental resistance 3) Biotic potential, exponential growth, J-shaped curve, factors affecting biotic potential a) Biotic potential= the reproductive capacity of an organism assuming optimum environmental conditions i) A maximal birth rate and minimal death rate b) As a population tries to reach biotic potential, exponential growth is possible i) This produces a J-shaped growth curve ii) Exponential growth occurs when each individual produces more than the single offspring necessary to replace itself iii) Factors that AFFECT biotic potential: (1) The age at which the organism 1 reproduces (a) Younger= faster rate (2) The frequency with which reproduction occurs (a) Increased frequency = faster rate (3) The average # of offspring produced each time (a) Increased offspring per litter= faster rate (4) The length of the organisms reproductive life span (a) Longer reproductive span= faster rate 4) Environmental resistance: density-dependent & density-independent factors a) Environmental Resistance: external factors that prevent a population from reaching biotic potential i) E.g. limited food and shelter due to competition ii) E.g. increase in predation as population grows and becomes more visible iii) E.g. increased spread of disease in more dense populations b) Density-independent factors limit population size regardless of the population density i) Can be natural disasters such as floods, fires, and earthquakes ii) Can be human-caused such as habitat destruction and pollution c) Density-dependent factors increase as the population increases i) E.g. ppredation increases as population grows and becomes more visible and abundant ii) E.g. less food and shelter is available as more organism are in competition with each other in the population iii) E.g. parasites, illness and disease spread more readily among organism in dense populations iv) BASICALLY THE LARGER A POPULATION GETS, THE MORE INTENSE THESE FACTORS BECOME. 5) Logistic population growth, S-shaped curve, carrying capacity a) Logistic Population growth: patter where populations increase to the maximum number sustainable by the environment, then stabilize. i) Biotic potential and environmental resistance areopposing forces (1) Usually result in a balance: the size of a population doest outgrow the resources available to support it (a) Instead of a J-shaped growth curve, we see an S-shaped growth curve ii) The maximum population size that can be sustained without damage to the ecosystem = the carrying capacity 6) Boom-and-bust cycles, invasive species, consequences of overshooting carrying capacity a) Not all populations follow logistic population growth i) Overshooting the carrying capacity is usually highly detrimental to the ecosystem ii) But some overshoot it often and predictably (1) This is seen in populations that undergo boom-and bust cycles (a) Boom-and bust cycles can be seen in short lived, rapidly reproducing species, such as prokaryotes, protists, and insects iii) Boom and bust populations are especially affected by seasonal changes such as changes in rainfall, temperature, or nutrient availability b) Overshooting the carrying capacity is especially common with invasive species i) Invasive species = organism that are introduced into ecosystems where they encounter very little environmental resistance (1) When introduced into a new ecosystem, the population may explode due to a lack of natural predators (a) Invasive species like kudzu outcomptete all other living things (plants, animals, etc. ) in the ecosystem, causing them to die (b) When the nutrients are all used up, the ecosystem collapses, unable to support life at the normal rate or at all. 7) Demography, # of humans now & general predictions, developed vs. developing countries a) The study of human populations= demography i) Demographic data are used to formulate policies in public health, housing, education, employment immigration, environmental protection, etc. b) There are more than 7 billion humans alive today. i) Our population is currently growing exponentially (1) Birth rates exceed death rates by so much that we add 80 million people to the world population each year. c) Most developed countries are not experiencing growth i) Most developed countries such as Japan, the US, Canada, Australia and most of Europe have growth rates that are leveling off d) Most developing countries show exponential growth i) Developing countries such as Mexico, Brazil, Southeast Asia, and most of Africa have very high population growth e) Using current birth and death rates worldwide the UN predicts that Earth’s population will grow to 8-11 billion people in a very short time. 8) Human ecological footprint, our carrying capacity, possible future consequences a) We know for certain that it cannot grow forever. b) We can get an idea by measuring our ecological footprint: the amount of land and water required to produce the resources for and remove the wastes of one person i) The amount of land and water on the planet divided by the amount used per person= number of people Eart can support (1) This can give us an idea of the carrying capacity for humans c) The UN calculates the human ecological footprint every year i) We need more than 1.5 plant Earths to sustain 7+ billion humans at the current level of resource use. d) The number of Earths needed is increasing quickly as Earth’s resources decline and the population still grows exponentially e) Unless we very quickly reduce our ecological footprint, we have already overshot our carrying capacity i) Can expect ecological damage that will significantly impact the human population f) POSSIBLE FUTURE CONSEQUENCES: i) We can increase carrying capacity but only if: (1) Er find new technologies that improve agricultural efficiency, conserve water, reduce pollutants, or recycle more of what we use (a) Current technology especially GMOs help, but it’s not keeping up with our current population, let alone our continuing growth (2) We lower our ecological footprint by reducing fossil fuel use, animal-based diets, etc. (3) We literally pull resources from another plant (a) We won’t get to Mars for 20 more years and it will be many decades longer until we can get to an Earth-like planet and back with resources Part 13: 1) Community interactions: 5 types, details & key terms (e.g. intra- vs. interspecific), how these drive coevolution a) Community interactions: i) Help limit population size (1) Populations maintain a balance between resources and the numbers of individuals consuming them ii) Drive evolution by acting as agents of natural selection b) Common community interactions include: competition, predation, parasitism, commensalism, and mutualism i) Competition occurs when 2 organisms attempt to use the same limited resources (1) Intraspecific competition is between individuals of the same species (a) Most intense because they require all the same things (2) Interspecific competition occurs between members of different species (a) E.g. they feed on similar things or require similar breeding areas (3) Each species occupies a unique ecological niche: (a) Encompasses all aspects of its life including: physical home or habitat, the environmental factors necessary for survical: nesting sites, climate, type of nutrients, etc. (i) The role the species perform within an ecosystem: what it eats, what other species it competes with, etc. (b) The more ecological niches overlap, the greater the competition. ii) Predation is an interaction in which one living thing eats another living thing (1) E.g. herbivores eat plants (2) E.g. carnivores eat other animals (a) Predation is a win/lose community interaction iii) Parasitisim is an interaction in which parasites live in or on their prey, which are called hosts (1) Examples include tapeworms, fleas, ticks and many types of disease-causing protists and bacteria (a) Parasitism is a win/lose community interaction iv) Commensalism is an interaction in which one species benefits but the other is not affected (1) E.g. tiny mites live, eat and breed in our hair follicles but we never notice (2) E.g. vultures eat the leftovers from a lion’s kill but do not affect the lion in any way (a) Commensalism is a win/neutral community interaction v) Mutualism is an interaction in which both species benefit from each other (1) E.g. lichens= fungus & algae (a) The algae provides food, the fungus provides protection (2) E.g. clownfish and sea anemones (a) The anemone protects the clownfish, who in turn chases off other fish that would eat the anemone (i) Mutualism is a win/win community interaction 2) Competitive exclusion vs. resource partitioning (1) Over time, competition leads to one of the two things: (a) The competition interaction is detrimental to allinvolved because resources are limited (lose/lose) (i) Therefore, it is adaptive for species to reduce competition as much as possible 1. Over time, species that don’t go extinct evolve with more and more separate ecological habitats and needs= resource partitioning a. Dividing up the resources minimizes the overlap of their niches and reduces interspecific competition (ii) Competitive exclusive 1. One species within the niche utilizes resources more efficiently, driving the other species to local extinction 3) Keystone species a) Within communities each species plays a role i) A loss of or change in one species has consequences for the entire community b) However, some communities rely most heavily on one particular species to keep the community in balance: this is the keystone species c) If a keystone species is removed, normal community interactions are significantly and dramatically altered i) Preserving just 1 keystone species has the effect of preserving many species at the same time How many people can live on planet Earth? View online for free - best quality is through Alkek library: go to http://www.library.txstate.edu/ - search the title, click “View Online” The answers to the following questions are simple, but still important. 4 or 5 questions on the exam will be based on the following: Who was the first to make the observation and publish that the Earth has limits, only able to support a finite number of humans, and that we needed to control reproduction? What percent of the water on the planet is actually available for human use? Within the next 20 years, about how much of the world’s population will live in areas of water stress? What city is the 8 richest in the world but has a buckling water system, with at least a million people affected by water shortages each day? Which uses the most water to produce: a cup of coffee, a can of beer, a hamburger, or a t- shirt? What does the “lion’s share” of water go to? What is the name of the Iowan farmer that saved millions of lives by improving agricultural productivity 5-fold? What was this revolution called? What area of the world will have an especially challenging time when their population doubles (in the very near future) and competition for farmland heightens? What are 3 ways we can reduce the load on the Earth? What helps some areas of the world have stable populations with small families (without coercion or aggressive government policies)? What crucial piece of medical technology has allowed the populations of many countries to reduce population growth in a short amount of time? Mexico City hired an urban planner and environmentalist to find a sustainable solution to their water shortages. What cycle will he try to reestablish? How is he trying to do that? How much has the human population grown in the time it took you to watch this video?
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