ELS 1st Term Past Paper PDF

THE UNIVERSE TWO SIDES: BIBLICAL CREATION ★ Science ★ 7 days: ○ Big Bang 1. light ○ Theories...

THE UNIVERSE TWO SIDES: BIBLICAL CREATION ★ Science ★ 7 days: ○ Big Bang 1. light ○ Theories 2. dome, sky ★ Faith 3. earth, land, seas, plants, and ○ God trees ○ Belief 4. sun, moon, stars ★ Both have strong evidence/s 5. sea creatures and creatures that could fly 6. animals and humans 7. rest ★ Omnipotent - God ★ Process BIG BANG THEORY (1920) ★ By Alexander Friedman and Georges Lamaitr ★ All the matter and energy in the universe are crammed into a tiny compact called singularity. Then suddenly, from this singularity, expansion or explosion took place sending space, time, matter, and energy in all directions ★ Everything started from a sudden explosion ★ Ung nasa tip (left side) is called the singularity, while ung mga nasa (right side) is the space, time, matter and energy that are sent in all directions Process/Parts of the Big Bang: 1. The cosmos goes through superfast “inflation” expanding from the size of an atom to that of a grapefruit in a tiny fraction of a second 2. Post-inflation, the universe is a seething hot soup (very hot, kumukulo) of electrons and, quarks and other particles 3. A rapid cooling cosmos permits quarks to clump into protons and neutrons. *May rapid cooling kaya nag cluclump ung particles (protons and neutrons) sa space.* Nucleosynthesis is the clumping of protons and neutrons. If protons and neutrons clump, then a nucleus of an atom is made. 4. Still too hot to form into atoms. Charged electrons and protons prevent light from shining; the universe is a superhot fog. *Naging steaming hot ung universe dahil sa fog and dahil duon, walang light na pumapasok. Wala pang atoms.* 1 11 HA - 11 Chelsea Jei M. Abulad  5. Electrons combine with protons and neutrons to form atoms, mostly hydrogen and helium. Light can finally shine. *The simple elements that are made are Hydrogen and Helium. Kapag nagkaroon na ng hydrogen and helium, makakagawa ng stars.* 6. Gravity makes hydrogen and helium gas coalesce to form the giant clouds that will become galaxies; smaller clumps of gas collapse to form the first star. *Stars have enough gravitational energy kaya they clump together which then creates galaxies. Since meron nang galaxy, meron na ring light that is shining through the universe* 7. As galaxies cluster together under gravity, the first stars die and spew heavy elements into space; those will eventually turn into new stars and planets. *Galing raw ang mga planets sa mga remnants ng star* 7 ERAS ★ Singularity era (0 to 10^-43) ★ Radiation era (10,000 years) ○ Also known as the “planck ○ Energy was in the form of era” radiation (wavelength) ○ Earliest known period of the ○ Cosmic microwave (remnant universe of the singularity after it ★ Inflationary era (10^-36 to 10^32s) expanded) background ○ The universe expanded from radiation the size of an atomic nucleus ★ Matter domination (300,000 years) to 10^35 meters in width ○ Matter began to dominate ★ Formation of the universe (10^-6s) ○ Electrons joined with ○ The universe was made of hydrogen and helium nuclei fundamental particles and to make small neutral atoms energy; quarks, electrons, ○ Simple atoms then form neutrons, and protons simple elements ★ Formation of the basic elements (3s) ★ Birth of star and galaxies (300 ○ Protons and neutrons million years) combined to form hydrogen ○ Slightly irregular areas of gas nuclei cloud gravitationally attracted ○ Pairs of hydrogen nuclei form nearby matter and became helium nuclei this is called denser nucleosynthesis ○ Gained enough mass to ignite and produce light 4 FUNDAMENTAL FORCES THAT MADE THE BIG BANG HAPPEN Fundamental Interactions : ★ Strong nuclear force ○ Force that binds nucleus ○ Where nucleosynthesis is formed or created ★ Electromagnetic force ○ Can be attractive or repulsive ○ Allows the celestial body to attract and repulse ○ Kaya may moons na pwede mag revolve (?) 2 11 HA - 11 Chelsea Jei M. Abulad  ★ Weak nuclear force ○ Short ranged forced present in radioactive decay (the opposite of nucleosynthesis, which is that they destroy/ breakdown an atom’s nucleus) ★ Gravitational force ○ Attractive force that binds the solar system ○ Can be seen sa 7th part ng big bang (where in may heavy elements na nag pakalat-kalat sa outer space na naging planets) ○ Gravity pulls us towards the sun ELEMENTARY PARTICLES THE SUPPORTING EVIDENCES OF THE BIG BANG: Galaxies moving away ★ The distance between galaxies is increasing with time ★ 1924, Edwin Hubble ○ Proposed Hubble’s law It states that the universe is expanding continuously The evidence that says that the big bang is true States that the galaxies are retreating from the milky way at a speed that is proportional to their distance Nakita niya dahil naglook siya sa hubble space telescope ○ Edwin Hubble at Mt. Wilson Hubble guiding the Hooker 100 inch telescope in 1923 Hubble’s observations at the 100 inch during the 1920’s led him to the conclusion that the universe is expanding and that an object’s recession velocity is proportional to its distance from the observer. The Hooker 100-inch telescope atop Mt. Wilson near Pasadena, CA. it was the largest telescope in the world from 1917-1947 3 11 HA - 11 Chelsea Jei M. Abulad  ★ Deep Hubble Space Telescope image ○ A deep image of an “empty” portion of the sky with the Hubble Space Telescope reveals that the universe is filled with galaxies- many just like our own. The light we see from the most distant galaxies has traveled approximately 10 billion years to reach us ★ Hubble’s Law (Edwin Hubble) ○ Analogy for an expanding universe: as the dough rises, raisins (galaxies) originally farthest apart travel greater distances than those located closer together. Thus, in an expanding universe (as with the raisins) more space is created between two objects that are farther apart than between two object that are closer together ★ Hubble also used the Red shift (Doppler shift) ○ If the galaxies appear to be red/orange (low energy) then it is far, but if it’s blue, indigo, or violet then it is nearer ○ Iba iba kulay ng galaxy dahil sa distance ○ He used the wavelength of the visible light Presence of cosmic microwave background (CMB) ★ 1960, Arno Penzias and Robert Wilson ★ CMB is speculated to be the remnant energy left over from the formation of the universe Abundance of light elements ★ Massive amounts of Helium and Hydrogen, with trace amount of Lithium and Beryllium ★ These elements are numerous kaya nasusupport nila ang big bang theory ★ Sila ang mga unang nabuo na elements during nucleosynthesis RED SHIFT (DOPPLER SHIFT) ★ Red shift, or a Doppler shift toward the red end of the spectrum occurs because the light waves are “stretched”, which shows that Earth and the source are moving away from each other. ★ ROYGBIV ang colors na ginagamit sa visible light 4 11 HA - 11 Chelsea Jei M. Abulad  ★ As a car moves, sound waves in front of it get squished up while those behind get spread out. This changes the perceived frequency, and we hear the pitch change as the car goes by. ○ Just like if the sound is near, then it is louder. But when it is far, then it is softer or more quiet ★ Just like sound from a moving car, as a star moves away from us, the light becomes redder. As it moves towards us, the light becomes bluer. Red: far, Blue: near STEADY STATE THEORY ★ By Bondi, Gold, and Hoyle (1948) ★ Stated that the universe is homogeneous (meaning it doesn't change) ★ The universe doesn’t change its appearance and is homogeneous. When an old star dies, a new star replaces it. So everything remains the same. The universe has neither any beginning nor any end. Universe was and will always remain the same the whole time Density of galaxies falls as universe expands Density of galaxies remains more or less constant as universe expands (space filled in by new galaxies) INFLATION THEORY (EXTENSION OF THE BIG BANG THEORY) ★ It states the things that the big bang theory can't answer ★ Offers solution to unresolve problems of the big bang theory, like: Flatness Monopole Horizon Big bang states there Big bang predicts Big bang states that space in should be curvature production of magnetic opposite directions are so far Things will appear flat poles apart they could never have even though it is curve Isa lang ang may dulo or contact with each other Universe is not flat point (tip), which is ung Since it is expanding, the galaxies It is more like a cone original sight for singularity would move apart from each other Hindi naman kasi siya na Ung isang side ng universe and not closer sabi ni Hubble kasi di walang dulo Universe is a vast horizon siya astronaut at tinignan Monopoles dropped Exponential expansion in early lang niya yung universe exponentially to universe presupposes that the through a telescope undetectable level during distant regions were much closer rapid expansion to each other prior to inflation 5 11 HA - 11 Chelsea Jei M. Abulad VOYAGER ★ Contains recording and pictures ★ Man made craft that went to space and interstellar ★ Used to capture things from space SLINGSHOT MANEUVER ★ Used by voyager 1 and 2 ○ Rode the orbit of jupiter and saturn to use their gravitational force to slingshot itself to a farther distance ★ Slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expenses ★ To save fuel and propel to farther distance ★ Ride an orbit of a celestial planet EARLY SOLAR SYSTEM MODELS ★ Heliocentrism ○ Helio: sun (the sun’s gravitational force is so strong enough to pull larger planets and celestial bodies to go to its right path) ○ Centrism: center ○ The center of the solar system is the sun ○ Earth and the other planets orbit the sun ★ Geocentrism ○ Geo: earth ○ Centrism: center ○ The center of the solar system is the earth ○ In the ancient Greeks’ geocentric model, the moon, sun, and the known planets—mercury, venus, mars, and jupiter—orbit earth SOLAR SYSTEM THEORIES ★ Rene Descartes “Vortex Theory” ○ A French national philosopher and mathematician ○ Proposed that the sun is at the center of a vast vortex of rotating invisible matter, and the swirl of the cortex carries the planets around, rather like leaves in whirlpool ~ principia philosophiae (1644) ○ Stars are capable to make a whirlpool, kaya ung mga rocks, planets, bodies sa space can rotate around it kaya nakakagawa ng solar system ○ Descartes further proposed that every star is a sun, with its own vortex, so the cosmos is a veritable sea of vortices 6 11 HA - 11 Chelsea Jei M. Abulad  ★ George-Louis Comte de Buffon “Collision Theory” ○ Collide ○ A french naturalist, mathematician, and cosmologist ○ Proposed that a comet striking the sun had broken off debris that became the planets or the solar system (planetesimals) ○ The earth was scorching, but gradually it cooled until molten rock turned to dry land and clouds rained down to form to form oceans ○ Estimated the entire process took over 75,000 years ★ Immanuel Kant “Nebular Theory” ○ A German philosopher ○ Published Allgemelne Naturgeschichte und Theories des Himmels (General Natural History and Theory of Heavens) ○ Suggested that the gravitational forces in a slowly rotating nebula would gradually flatten it and create within it several denser clouds of gas which would separately compact themselves into distinct spheres, the sun, and planets ○ Most accepted theory ★ Marquis Pierre Simon de Laplace “Solar Nebular Theory” ○ A French astronomer ○ The sun, planets, and their moons began as a whirling cloud of gas — Exposition du systeme du monde (Exposition of the System of the World) (1796) THE FORMATION OF THE SOLAR SYSTEM 1. Collapse ★ High temp gas ball collapse then heat up and then become disk shape 2. Spinning ★ Disk spins faster and faster and temperature decreased 3. Flattening ★ Disk become sphere due to rotation, because of fast rotation, some of the fog escape 4. Condensation ★ Some fog formed the core of the largest mass in the middle, while small part formed around cooling process 5. Accretion ★ Cores of smaller mass turns into planets, while most remain in a high-temp flare 7 11 HA - 11 Chelsea Jei M. Abulad  THE SOLAR SYSTEM Sun→Mercury→Venus→Earth→Mars→Asteroid Belt→Jupiter→Saturn→Uranus→Neptune ★ There are many planetary systems (planets revolving around a star) like ours in the universe, with planets orbiting a host star. Our planetary system is call “the solar system” because we use the word “solar” to describe things related to our star, after the Latin word Sun, “solis” MEMBERS OF THE SOLAR SYSTEM Solar winds Heat of the sun that is extended from the center to the vast end of the solar system Sun A yellow dwarf star that radiates from the center to the end Giant ball of glowing gas that makes a lot of energy Energy is very vital for the photosynthesis Brings warmth and light Center of the solar system Main energy source or main warmth 8 PLANETS OF THE SOLAR SYSTEM Terrestrial planets ★ Majority of the planets are made of rocks and metal ★ Substantially smaller ★ Short orbital periods and less satellite ★ Move slowly in space ★ No rings and few moons (if any) ★ Have a diameter of less than 13,000 km Mercury Venus Earth Mars Closest to the 2nd planet from Third planet from the sun “The red planet” sun the sun Only planet with large Cold and dusty ung Half and half “The Evening star” amount of liquid water surface (half is : bright in the sky (important ung water 4th planet sobrang init during night because need din siya sa Has 2 moons and half is The hottest planet photosynthesis, pag Volcanoes and canyons sobrang lamig) because the walang photosynthesis edi Rocks and sand kaya extreme greenhouse walang producers kapag Very thin atmosphere ung temp gasses is high (it walang producers edi Landscape ng mars is Gray and traps the uv walang consumers which similar to earth, the tempt smallest planet transmission is tayo) and distance to the sun Rocky crust inside the planet) Only planet with living too pero walang water with craters Orange in color things (kaya tinitignan pa ng mga Second most and rich in Most dense planet astronauts kung pwede denses planet poisonous fog tumira) 8 11 HA - 11 Chelsea Jei M. Abulad Jovian planets or Gas giants ★ Substantially larger ★ Long orbital periods and numerous satellites ★ Made up of mostly gasses (primarily hydrogen and helium) ★ Moves quickly in space ★ Have rings and many moons ★ Have a diameter of greater than 48,000 km Jupiter Largest planet – attracts 80 to 95 moons (largest moon in jupiter is larger than mercury) Giant ball of swirling gas Punong puno ng atmosphere and storm Has a large red spot which is a giant storm or hurricane (2x larger than earth) Has two very thin rings Saturn Most amazing planet because of its rings (made up of frozen gas, ice and rocks) Made mostly of helium and hydrogen Uranus Looks like it is on its side 90 degrees angle Ice planet May ring din Made up of gas Blue-green in color Lulubog if nag lan Neptune Most distant major planet “Mathematician’s planet” (because siya unang nahanap na planet through mathematical computations, calculating the orbit ng uranus para macalculate ang location ng neptune, not needed to be travelled in space para malaman kung saan siya) First planet located through mathematical calculation Blue in color Two dark spots Super layo sa sun Similar daw sa uranus Pluto Nawala na kasi naging categorized as dwarf planet Kala nila planet siya before, tas na categorize as dwarf planet (2006) Considered as one of the neptune's moon Grey in color 9 11 HA - 11 Chelsea Jei M. Abulad Dwarf planet (5) Planet-like but smaller and their gravitational force is not enough to clear their own orbit, not strong enough to clear their path along the sun Pluto Eris Haumea Makemake Ceres OTHER MEMBERS OF THE SOLAR SYSTEM ★ Moons ○ Come in many shapes, sizes, and types. A few have atmospheres and even hidden oceans beneath their surfaces. Most planetary moons probably formed from their discs of gas and dust circulating around planets in the early solar system, though some are captured objects that formed elsewhere and fell into orbit around larger worlds ○ Attracted to planets or celestial bodies ★ Asteroids ○ Sometimes called “minor planets” ○ Are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago ○ Most are debris ○ Rocks and metals ○ Rocky body smaller than a planet that orbits the sun ○ Giuseppe Piazzi (Italian) In 1801, he discovered the very 1st asteroid (Cerest) in space ○ NEAR - shoemaker Near earth asteroid rendezvous - shoemaker Renamed after Eugene Shoemaker Monitors near-earth asteroids Landed successfully on eros ★ Comet ○ Ice and frozen gasses ○ Icy body that releases gasses as it orbits the sun ○ Ice ball, gas ball, frozen ice ○ Made of nucleus (ball of energy) which is covered by a coma (made of hydrogen envelope) that is a vapor cloud ○ Buntot niya is a ion tail (ung parang light and made of plasma) and dust tail (made of hydrogen envelope) ○ 2 types of comets: Long period comet (more than 200 year to complete the orbit of the sun) or short period comet (less than 200 years to complete an orbit around the sun) ○ Source of comets: Oort cloud Long period comets By Jan Oort Cosmographical boundary of the solar system 10 11 HA - 11 Chelsea Jei M. Abulad  Kuiper belt Short period comets Found around or near the orbit of neptune By Gerard Kuiper Haley’s comet (76 years) Encke’s comet (3 years) ★ Meteoroid (nasa space) ○ Fragments of either an asteroid or a comet (mga natanggal na pieces) ○ Floating in space ○ Rocky or metallic fragment of an asteroid, comet, or planet ★ Meteor (papunta na sa earth) ○ Kapag nagenter ng earth ung meteoroid ○ Kasi kapag pumunta sa earth nagkakaroon ng sunog ○ Streak of light seen when a meteoroid heats up in the atmosphere ★ Meteorite (nasa ground ng earth) ○ Fragment na nasa meteor na nahulog na hindi na burn sa atmosphere ○ Meteor fragment that reaches the ground 2 TYPES OF MOVEMENTS OF THE PLANET IN THEIR ORBIT ★ Prograde ○ Planet follows the direction of its orbit ○ Planet that move in direction of its path/orbit ★ Retrograde ○ Planet opposes the direction of its orbit ○ Planet that move in opposite direction of its orbit/path ○ This is normally an optical illusion because members of the solar system move in different time and distance. 11 11 HA - 11 Chelsea Jei M. Abulad  GEOLOGICAL TIME SCALE — History of the planet in accordance to when an organism has lived 2 WAYS TO FIND THE AGE OF DIFFERENT ARTIFACTS ★ Absolute dating ○ There is an exact age of the artifacts or a site ○ Determines and finds the exact numerical age ○ Works better for igneous and metamorphic rocks ○ Radiometric method (uses radioactive decay – the half life of an element in the periodic table, it’s the enough time needed for the breakdown of element), amino acid (protein) dating dendrochronology (for plants and trees; looking at the annual rings like on the trunk of tree, may bilog bilog, so if ilan ung rings = age) and thermoluminescence (it uses heat to identify crystalline materials) ○ Examples of radioactive decay / radiometric method: Carbon 14 – living things na may half life na 5730 years meaning if beyond na yan edi wala nang radioactive decay so kapag may bone na may carbon 14 edi di pa umaabot ng 5730 years Boron – 5 days ang half life, if nakahanap ka ng artifact na walang nitrogen pero may boron edi more than 3 days na pero less than 5 days Nitrogen – 3 days lang half life nya, pag wala nang nitrogen edi more than 3 days na ang artifact ○ High precision ★ Relative dating ○ Tells the sequence ○ Sequence / order / older / younger ○ Arranges fossils in order ○ Works better for sedimentary rocks ○ Determine the which object is older ○ Biostratigraphy (looks for the layers of rocks, strata: layers of rocks) stratigraphy (science examining sedimentary rock layers) & cross dating thermoluminescence ○ Low precision NICOLAS STENO ★ Father of study of fossils ★ Scientist with major fundamental contributions ★ Proponent ng pag-aaral ng strata or rock layers to identify the age of fossils ★ Steno's law - all crystal of the same mineral, the angles is the same TYPES OF ROCK LAYERS ★ Superposition ○ Top is the youngest and the one below is the oldest ○ Rock layers in the bottom are older than those on top of them 12 11 HA - 11 Chelsea Jei M. Abulad  ★ Original horizontality ○ All rock layers are formed horizontally ○ Rock layers form in horizontal position ○ Lahat ng lupa ay tumataas dahil ito ay napapatungan horizontally ○ Example mga bundok, mount everest ○ ★ Lateral continuity ○ Rock layers are extended laterally (extended laterally ung dulo) and continuously ○ ★ Cross-Cutting Relationship ○ Rock layers that are cut across (nahati - called intrusion) are older than the cut itself ○ Mas older ung hinati ng intrusion bago ung intrusion ★ Principle Inclusion ○ Any inclusion in rock layers are older than the rock that contains it ○ Inclusion is ung bilog bilog na kulay blue (mas older siya or mas mauuna siya kesa sa pink na rock layer) TYPES OF FOSSILS ★ Petrification ○ Form when minerals replace the structure of an organism ○ Plants are already petrified ○ Wood is replaced by minerals ★ Compression ○ They are formed due to the burial of plants or plant parts in sediments ○ Parts ng halaman (madali daganan ng bato kasi thin) ay nacompress or nadaganan ng bato kaya nagleave ng imprints or bakat sa bato 13 11 HA - 11 Chelsea Jei M. Abulad  ★ Mood and cast ○ Are three dimensional and preserve the surface contours of the organism. A mold preserves a negative imprint of the surface, while a cast preserves the external form of the organism ○ Mold - palubog ung structure na nakuha (negative imprint of the surface) ○ Cast - pataas or pacurve na shape ung nakuha (3D) (external form) ★ True fossils (Preserved remains) ○ Preservation of original skeletons and soft body parts ○ Kita ung preserved animal or remain sa loob ng crystal or ano man ★ Ichnofossil ○ Marks, traces, carvings on the wall, cave, rocks which tells you the lifestyle of an organism ○ Used from the previous life HISTORY OF THE EARTH (that is used from the geologic time scale) ★ The geologic time scale is a time scale organized according to when organisms lived on earth ★ This is based on the appearance and disappearance of lifeforms ★ Hadean eon ○ Also called “Chaotic world/earth” Dito nabuo ang planet natin ○ 4.6 to 4.0 billion years ago ○ Nagstart sa earth coalescing (Earth Coalesced) From a cloud of dust, gravity molded our solar system The terrestrial planets were positioned closer to the sun. After Mars, these are the gas outer planets 14 11 HA - 11 Chelsea Jei M. Abulad  ○ Primordial water Continuous of bombarded ng asteroids Comes from comets and asteroids that collide during its early formation ○ Earth meet moon The center of earth attracted the moon The giant impact hypothesis explains the formation of our moon ○ Core accretion Iron and nickel is the core of the planet Solar winds swept in hydrogen and helium closer to the sun because they were smaller in size. But the sun couldn’t pull in the heavier elements. They spirited and gelled together into planets of their own. ○ Magnetic field Kaya nakuha ung moon ○ Asteroids and comets pelted Earth The earth was still in the late heavy bombardment stage This is why scientist suggest that comets may have transported water during the late bombardment stage ○ Summary: We obtained a heat source, magnetic field, and formation of a moon There are no fossil records because the temperature is too high (hot) to sustain life Heat flow was nearly 3 times as high as it is today from planetary accretion ★ Archean era ○ 4.0 to 2.5 billion years ago ○ Dahil continuous and bombardment ng asteroid nagkaroon ng Very First Ocean Earth began cooling in the Archean Eon. And because it was cool enough, water could finally condense to form its first oceans ○ Formation of DNA-Based Genes Protocells with RNA-based genes around 4000 Ma, after which true cells (prokaryotes) evolve along with proteins and DNA-based Nagkaroon na ng proteins Nagkaroon ng RNA na nag evolve to DNA ○ Ung ocean floor nagreact sa heat ng core kaya may paggalaw ng lupa na naging essential para makabuo ng continents or large mass. (The First Tectonic Activity Builds Continents) Because plate tectonics is necessary for building continents, this means tectonic activity was present in this eon ○ The first continent We have 7 continents Dahil sa seismic activity This resonates with the fact that Earth’s crust was cooling in the Archean Eon. This cooler climate allowed the formation of continents because the lithosphere became more stable 15 11 HA - 11 Chelsea Jei M. Abulad  ○ Ung RNA sa ocean naglead sa prokaryotic bacteria In this eon, Earth’s atmosphere was mostly methane and nitrogen. The only life forms that could exist were anaerobic cyanobacteria Anaerobic (di nag-uuse ng oxygen kasi toxic element sa kanila yun) ○ Iron collects on the seafloor As oxygen filled the oceans, it mixes with iron. Iron rusts when it reacts with oxygen. So over time, the seafloor collected rusted iron We can find banded iron formation all over the world such as Australia, Canada, and Russia ○ Ung iron sa ocean floor kinakalawang kaya nagkaroon ng Great Oxygenation Event Oxygen continued to form rusted iron in the oceans. Because there was no more iron to rust in the oceans, oxygen entered the atmosphere Nagkaroon nito para magproceed ung oxygen sa atmosphere ○ Summary A time when earth’s climate began to stabilize Earth cooled down from its molten state. It eventually could support oceans. Tectonic activity build continents In the Archean Eon, oxygen filled in the atmosphere, and most of the world’s iron ore was deposited ★ Proterozoic eon ○ 2500 to 541 million years ago ○ Oxygen Crisis Ung oxygen na ginagamitan ng cyanobacteria made it difficult for them The reason why this event is called an “oxygen crisis” is that cyanobacteria threatened their own existence through their own waste oxygen ○ First eukaryotes First hypothetical eukaryotes: Multicellular Francevillian biota ○ Snowball earth When oxygen is combined with methane, it produces carbon dioxide. Because there was less methane in the atmosphere, the greenhouse effect wasn’t as strong. With less heat trapped in the atmosphere, Earth froze for about 300,000,000 years ○ Oxygen crisis naging evolution na naging eukaryotic cells that uses oxygen kaya naging snowball ung earth (naging malamig) ○ The emergence of eukaryotes Scientists believe eukaryotic cells evolved when one simple cell engulfed another through endosymbiosis. Then, multicellular life developed because multiple cells benefited by cooperating like an ant colony From eukaryotic naging multicellular sila In-engulf ung cell (kinain) and then naging 2 cell living together ○ And it led to the stabilization ang ozone layer kaya naging livable ung earth 16 11 HA - 11 Chelsea Jei M. Abulad  ○ The presence of an ozone layer After the Great Oxygenation Event, oxygen atoms could bond and form an ozone. Over time, Earth’s ozone layer thickened in the upper atmosphere ○ Summary Earth completely froze into snowball earth or slushball earth Because of the oxygen-enriched atmosphere, the ozone layer thickened, and cyanobacteria were threatened There’s evidence that eukaryotes and multicellular organism evolved ★ Paleozoic era ○ The Cambrian Explosion The Cambrian explosion marked the first time in Earth’s timeline that we could observe fossils. So suddenly, we could observe fossils, exoskeletons and shells from this period ○ Organisms this time is vertebrates ○ Napunta sa evolution ng fishes at fungi ○ The Age of Fishes These fish had spines, jaws, and mouths which humans share with these vertebrate ancestors. Early sharks and lobe-finned fish swam in the oceans at this time ○ Dahil lahat ng fishes ay aquatic dapat may umalis kaya may nagmove sa land and; ○ Kaya nagkaroon ng age of amphibians ○ Ung trees naging coal tas nakikinabang tayo dahil sa ○ May permian extinction ★ Mesozoic era ○ From reptiles to amphibians ○ Age of Reptiles Reptiles gained an ecological advantage because they had less competition for food in dryland conditions. This triggered the start of the age of reptiles The reptiles lived in the pangea ○ Di namumulaklak ung trees kaya may confers ○ Age of Confers The Mesozoic Era marked the rise of conifer trees. Conifers like redwoods and pines were the major source of food for herbivore dinosaurs ○ Age of Dinosaurs Dinosaurs were the dominant land vertebrates of Earth. This existed until the Cretaceous- Paleogene extinction Nagkaroon ng age of dinosaurs kasi malaki ung lupain, oxygen, and puno before 17 11 HA - 11 Chelsea Jei M. Abulad  ○ Transition Coming Birds, small mammals, and flowering plants Mammals and birds both evolved from reptile-like ancestors. flowering plants are the dominants species of plants Dinosaurs are the ancestors of birds Nagkaroon ng lineage of mammals Ung mammals ang naging food ng dinosaurs ★ Cenozoic era ○ Nagkaroon ng extinction, starvation, and asteroid impact; ○ That’s why thee dinosaurs went extinct It was the Cretaceous- Paleogene (K-Pg) extinction event that wiped out the dinosaurs ○ Mammals diversified Warm-blooded mammals diversified to land, air, and sea habitats. It was the peak of evolution in the age of mammals Naging diverse or naging food chain ung mammals ○ Grass Spreading Spreading of grassy ecosystems Nagkaroon ng small shrubs ○ Apes There was a shift from four legs to two Nagkaroon ng 2 legged animals called apes pero apes ○ Stone Age Hominids were the early proto-humans who really began to master the use of their hands and fingers A group of 2 legged primates that used rocks as tool which is why we learned how to cultivate the land ○ Homo Sapiens Also known as ‘modern-day man’ is what we are today ○ Modern land 5 MASSIVE EXTINCTION 1. Ordovician-silurian extinction 440 million years ago (MA) ★ Scientists theorize that there were two main phases to these extinctions: a glaciation event and a heating event. Abundant plant life removed carbon dioxide from the air, causing global cooling and glacier formation. This led to a drop in sea levels, reducing habitat. Later came global warming and sea level rising again. Creatures that had adapted to the cooler climate were unable to survive the increased temperature. Since most fauna was marine at the time, 86% of life was lost ★ May matinding extinction or pagka yellow(?) 18 11 HA - 11 Chelsea Jei M. Abulad  2. Late devonian extinction – 365 MA ★ About 75% of life died off during this period. One theory suggests that land plants developed deep roots, releasing an abundance of nutrients into the oceans that fed algae. Because of this, algae blooms consumed vast amounts of oxygen in the oceans, suffocating many species. Another theory suggests that another global cooling took place, resulting in glaciation and a fall in sea level, leading to habitat loss ★ 75% has been extinct dahil sa nutrients bloom that led to the toxicity or pagkalason ng organisms 3. Permian-triassic extinction – 252 MA ★ The permian-triassic was the deadliest extinction in history: 96% of all life perished. Scientists believe that volcanic activity in Siberia puts massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere. Bacteria that thrive on carbon dioxide began producing methane, another greenhouse gas. Large quantities of both gasses warmed the planet and combined with earth’s water, making the ocean and rain acidic, creating a highly toxic environment for life ★ 96% of life force ★ Tumaas ung greenhouse toxicity kaya namatay yung mga animals 4. Triassic-jurassic extinction – 201.3 MA ★ Some scientists theorize that volcanic eruptions spewed tons of carbon dioxide into the atmosphere, which trapped heat and acidified the oceans, causing this mass extinction. Other scientists contend that an asteroid or comet impact triggered the extinction. About 80% of life was lost in this extinction, including most of the mammals, making way for the dinosaur’s ancestors ★ Extinction ng dinosaurs ★ May dinosaurs na nawala dahil daw sa asteroid 5. Cretaceous-paleogene extinction – 66 MA ★ The cretaceous-paleogene extinction wiped out the dinosaurs, along with 60-76% of all life on earth. A widely accepted theory is that an asteroid landed in the Yucatan Peninsula in Mexico and killed the dinosaurs. The impact would have ejected enormous amounts of debris into the atmosphere, causing global temperatures to drop. The impact may have also caused local fires, earthquakes, tsunamis, and acid rain ★ 60-76% ang na extinct na animals (like dino and big reptiles) ★ Nagka ice age or global temperature drop and global fire 6. Holocene extinction 11,700 years ago to present ★ The next mass extinction may already be happening. The current extinction rate is at least a thousand times greater than the “normal” extinction rate. A “normal” or background extinction rate is the average rate of extinction based on the longevity of species through record. Scientists believe that human impact on the environment is the leading cause of extinction today ★ Caused by irrelevant activity of mankind ★ It is happening right now that is why we should take care of the environment 19 11 HA - 11 Chelsea Jei M. Abulad