Life Science

Characteristics of living thingsLiving things are organized All living creatures can be organized in hierarchy levels. Also living organisms are made

of cells, the smallest unit of life.

Living things acquire materials and energyLiving organisms need to consume gather and consume energy. While autotrophs can

make their own food, heterotrophs need to capture and consume other organisms to get their energy.

Living things respond to their environmentOrganisms need to react to stimulus in their environment to ensure their survival.

Living things reproduceLiving creatures need to reproduce to pass down their DNA, while some organisms

reproduce sexually, other can reproduce by themselves (asexually).

Living things have the ability to adaptLiving organisms need modifications to survive in their environment. The individual with

better adaptations has more chances to survive and reproduce.

Classification of Living ThingsSystematics is the discipline of identifying and classifying organisms according to some criteria. Each organism needs to be placed in a species, genus, family, order, class, phylum, kingdom, and domain.

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Fro

m g

en

era

l to p

articu

lar

Taxonomy is the assignment of a binomial name to a specie. The first part of the name is the genus to which the specie belongs, and the second part is the species name.

HomeostasisAll living organisms need to maintain an internal equilibrium in their bodies for their survival. Homeostasis is the maintenance of normal conditions inside an organisms achieved by the control of various physiological processes. If internal conditions were to changed drastically, diseases may occur.

Cell TheoryBasic principle of biology created by

Theodor Schwann and Rudolph Virchow.The theory states that: 1. The cell is the basic unit of life 2. All living things are composed of cells 3. Cell arise from pre-existing cells. The modern version states that: energy

flow occurs in cells, DNA and genes are passed from cell to cell, and all cells have same basic chemical composition.

Theory of Evolution by Natural SelectionTheory proposed by Charles Darwin.The theory states that:1. Species change depending on time

and place2. All life forms share a common

ancestor3. Evolutionary change is slow Darwin proposed that natural

selection determines the course of a specie.

Survival of the fittest: Organisms better adapted to their environment have more chance to survive and pass their genes onto the next generation.

Origin of Life Theory (Oparin-Haldane)Theory created by Aleksandr Oparin and

J.B.S. Haldane.Theory that proposes that early

eukaryotes (first unicellular organisms) emerged form nonliving matter through a process of million of years.

According to both the Earth’s primitive atmosphere was filled with hydrogen, carbon dioxide, ammonia, and water vapor.

While Oparin proposes that methane is the source of carbon life, Haldane thanks that carbon dioxide is the main source.

Malthus Theory of PopulationTheory proposed by Thomas Robert

Malthus in his famous An Essay on the Principles of Population.

The theory proposes that as long as human population increases in geometric proportions, food will also increase only in arithmetic proportions.

Malthus said that if population increased uncontrollably then food will grow scarce and famine and diseases will arise.

BiodiversityBiodiversity is the total

number of species, the variability of their genes, and the communities in which they live.

Conservation of a great biodiversity is important to preserve species, ecosystems, and our existence.

Present biodiversity is estimated as 5-30 million species, of which fewer than 2 million are identified and named.

BiomeBiome is one of the biosphere’s major communities,

characterized by climatic conditions and type of plants.Biome climate is mostly decided by latitude and altitude.Some biomes are tundra, taiga, temperate forest, tropical forest,

shrublands, grasslands, and deserts. Biomes can house many large ecosystems of animals and plants.

EcosystemEcosystem is a biological

community together with the associated abiotic environment; characterized by energy flow and energy recycling.

In this specific area all aspects of the environment interact and affect each other.

Disappearance of a specie, human intervention, or pollution may destroy the balance in an ecosystem

Food Chain•Food chains are linear graphical representations of how animals get food and obtain their nutrients.•Chains usually start with human plant-life, continue with herbivores, and finish with carnivores (sometimes scavengers are included in food chains).•Their main objective is to show the prey-predator relationships in a defined ecosystem.

Food Web•Food webs are graphical representations that interconnect various possible food chains in an environment.•Their goal is to show all possible prey-predator relationshps in a defined ecosystem.•Food webs demostrate that when there are more predators than preys, the predators’ population tends to decrease.•Species in a food web are called nodes, while the lines that connect them are called links.

Trophic Levels•Trophic levels are the feeding levels of a population in a food chain.•Trophic levels show how energy flows in a single path.•Autotrophs (plants and trees) in the lowest level of the trophic levels are called primary producers.•The herbivores that consume plants are called primary consumers.•Carnivores that eat herbivores are called secondary consumers.•Carnivores that feed on other carnivores are called tertiary consumers.

•Energy is partially lost as its flows from one level to the next one, so each level receives less energy than the one before it.•Around 10% of energy from a level passes to the next trophic level.

Biotic and Abiotic Factors•Biotic factors are all living factors (producers, consumers, and decomposers) within an environment that affect the life and interaction of another organism. Other factors like disease, parasitism, and predation are also considered biotic factors.•Abiotic factors are nonliving factors in an ecosystem that affect organisms in that environment. Some abiotic factors are weather, habitat, natural cycles (water, carbon, nitrogen,etc.), water availability, type of soil, and pollution level.

PollutionPollution is any change in the environment that has adversely effects in the lives of the organisms. Pollution is usually caused by human actions and natural disasters. There are 3 types of pollution: water pollution, land pollution, and air pollution.

Cause Effects

Factories and cars that produce smoke with chemicals and fumes.

Air becomes polluted and may cause disease when breathed.

Excessive garbage in land and people littering everywhere.

Animals that eat litter may die and garbage accumulated pollutes the soil for plants and trees.

Companies dumping wastes on rivers and oil spills in oceans.

Water is polluted and becomes toxic for animals and plants. Also some animals are trapped in garbage and die.

Ozone Layer Depletion•The ozone layer is a filtering layer in the atmosphere (formed by oxygen) that protects Earth from ultraviolet radiation.•Due to excessive contamination there is a seasonal thinnng of the ozone shield.

Causes Effects

Increase in levels of radicals (such as atomic chlorine and bromine).

More harmful effects of ultraviolet rays

Airplanes and other transporst taking advantage of the ozone layer to fly

Climate change (global warming)

Excessive pollution of air

Alteration of ecosystems

Greenhouse Effect•The greenhouse effect is the reradiation of solar heat toward Earth due to assumulation of greenhouse gases (methane, carbon dioxide, water vapor, nitrous oxide, and ozone.•Some causes of greenhouse gasses’ accumulation are excessive burning of fossil fuels, clearing of forest, and other human activities.

•Effects of the greenhouse effect include rise of global temperature (global warming), alteration of natural cycles (including the carbon cycle), and ecological impact (plants receive more sunlight and heat than usual).

Acid Rain•Acid is rainfall with a pH lower than 6.5 formed due to the combination of sulfite and nitrogen with moisture in the air. This results in acids that fall as rainfall across various environments.

Causes Effects

Use of fossil fuels that produce sulfur dioxode.

Poisoning of soil, trees, and plants

Volcanoes and rotting vegetation that increase level of sulfur dioxode

Corrosion of paints, metals, textiles, and other man-made objects

Production and use of fertilizers that increase the level of noxied of nitrogen and fulfur dioxide in the air

Pollution of whole habitats and environments (lakes and rivers worsen the effect)

Eutrophication•Eutrophication is the overenrichment of water by inorganic nutrients (mostly from human activities), that leads to excessive bacterial growth and oxygen depletion.

Causes Effects

Wastes of sewage water pipes

Exccesive growth of polluted algae

Excessive animal waste Large quantity of acids

Application of commercial fetilizer

Death of marine organisms

Loss of Biodiversity•Biodiversity is the total number of species, the variability of their genes, and the communities within an environment.•Diversity of life depends on food availability, geography, and climate.

Causes Effects

Excessive hunting Extinction of a specie (which can cause a great negative effect in food chains)

Habitat destruction (deforestation or natural disasters)

Low food availability for humans and predators

Excessive pollution of soil

Vulnerability of ecosystems to natural disasters

Anderson, Phil. "Energy Movement in Ecosystems: Trophic & Energy Pyramid." http://schoolworkhelper.net/. St. Rosemary Educational Institution, January 2, 2011. Web. Retrieved on: Monday 21st February 2011. http://schoolworkhelper.net/2011/01/energy-movement-in-ecosystems-trophic-energy-pyramid/.

Bailey, Regina. "Cell Theory." Biology. New York Times, 2011. Web. 21 Feb. 2011. <http://biology.about.com/od/biologydictionary/g/celltheory.htm>. Biology Online Org. "Biotic Factor - Definition from Biology-Online.org." Life Science Reference - Biology Online. 25 July 2008. Web. 21 Feb. 2011.

<http://www.biology-online.org/dictionary/Biotic_factor>. Bora, Chandramita. "Ozone Layer Depletion: Effects and Causes of Ozone Depletion." Buzzle Web Portal: Intelligent Life on the Web. 2011. Web. 21 Feb. 2011.

<http://www.buzzle.com/articles/ozone-layer-depletion-effects-and-causes-of-ozone-depletion.html>. Buckley James. "[Regents Prep Living Environment] Ecology: Biotic vs. Abiotic." Oswego City School District Regents Exam Prep Center. 2003. Web. 21 Feb.

2011. <http://regentsprep.org/regents/biology/units/ecology/biotic.cfm>. Buzzle.com. "Thomas Malthus: Theory of Population." Buzzle Web Portal: Intelligent Life on the Web. 2010. Web. 21 Feb. 2011.

<http://www.buzzle.com/articles/thomas-malthus-theory-of-population.html>. Chapgar Jasmine. "Food Chain - Kid's Corner." Sheppard Software: Fun Free Online Learning Games and Activities for Kids. 2009. Web. 21 Feb. 2011.

<http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/foodchain.htm>. ChemGaroo. Chemgaroo Chempedia. Web. 21 Feb. 2011. <http://www.chemgapedia.de/vsengine/vlu/vsc/en/ch/16/uc/vlus/eutrophication.vlu/Page/vsc/en/ch/

16/uc/chemicalcycles/nitrogen/eutrocausesandeffects.vscml.html>. Critchfield, Howard J., "Deserts", The New Book of Knowledge, 1998 ed. Cruz Lisa. "Characteristics of Living Organisms." Cruz Lectures. Web. 21 Feb. 2011. <http://lisacruz2.tripod.com/id30.html>. Czech Technical University. "Zambia Eclipse Expedition 2001." Aldebaran Homepage. 2001. Web. 21 Feb. 2011.

<http://www.aldebaran.cz/actions/2001_africa/en_gallery_fauna.html>. Darling David. "Oparin-Haldane Theory." The Worlds of David Darling. Web. 21 Feb. 2011.

<http://www.daviddarling.info/encyclopedia/O/OparinHaldane.html>. Jue Tao. "BIOLOGY HOMEWORK." JueTaoFanClub. 30 Dec. 2008. Web. 21 Feb. 2011. <http://juetaofanclub.blogspot.com/2008/12/biology-homework.html>. Lambert, Wayne, "Deserts", The World Book Encyclopedia, 1994 ed. Mader, Sylvia. Inquiry Into Life. Mc Graw Hill: New York, 2008.

<http://www.kidsgeo.com/geography-for-kids/0164-ecosystems.php> Muchapedia. "Greenhouse Effect." MUCHAPEDIA: Your Alternative Energy Resource. 2009. Web. 21 Feb. 2011. <http://www.muchapedia.com/greenhouse-

effect.html>. OTONetworks. "Pollution, Water Pollution, Air Pollution | GreenStudentU.com." GreenStudentU: Green Students, Environmental Education, & Eco-Lifestyles.

2010. Web. 21 Feb. 2011. <http://www.greenstudentu.com/encyclopedia/pollution>. Orthodox Resource Center. "Humannity-s Place in the Cosmos." Orthodox Christianity for Absolute Beginners. 2010. Web. 21 Feb. 2011.

<http://www.orthodoxresource.co.uk/creator/microcosm.htm>. Putatunda, Rita. "Causes and Effects of Acid Rain." Buzzle Web Portal: Intelligent Life on the Web. 2011. Web. 21 Feb. 2011.

<http://www.buzzle.com/articles/causes-and-effects-of-acid-rain.html>. SalvoDSilva. "Food Chain Diagram." Boyfriend Nicknames, Nicknames for Guys, Boys Cute. Web. 21 Feb. 2011.

<http://www.osovo.com/diagram/foodchaindiagram.htm>. TeachNet. "POLLUTION CAUSE AND EFFECT TABLE." Welcome to the Lab Site of TeachNet. Web. 21 Feb. 2011.

<http://www.teachnet-lab.org/miami/2002/elinero2/pollution_cause_and_effect_table.htm>. University of Michigan. "Evolution and Natural Selection." The Global Change Program at the University of Michigan. Web. 21 Feb. 2011.

<http://www.globalchange.umich.edu/globalchange1/current/lectures/selection/selection.html>. West Tisbury Elementary School, Schaffner Brynn. "Desert Biomes." Blue Planet Biomes. 2010. Web. 21 Feb. 2011.

<http://www.blueplanetbiomes.org/desert.htm>.

References