The Beginning of the Universe PDF

{ In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. - Douglas Adams  Earth formed around 4.54 billion years ago, by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmospher...

{ In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. - Douglas Adams  Earth formed around 4.54 billion years ago, by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. While the Earth was in its earliest stage (Early Earth), a giant impact collision with a planet-sized body named Theia is thought to have formed the Moon. Over time, the Earth cooled, causing the formation of a solid crust and allowing liquid water on the surface. Origin of the Universe The universe began about 14.4 billion years ago The Big Bang Theory states that, in the beginning, the universe was all in one place All of its matter and energy were squished into an infinitely small point, a singularity Then it exploded Origin of the Universe The tremendous amount of material blown out by the explosion eventually formed the stars and galaxies After about 10 billion years, our solar system began to form.  Birth of the Solar System We know how the Earth and Solar System are today and this allows us to work backwards and determine how the Earth and Solar System were formed Plus we can look out into the universe for clues on how stars and planets are currently being formed  Other Solar Systems We have now discovered over two hundred planets orbiting other stars The processes that created our solar system have also created an uncountable number of other solar systems  The Nebular Hypothesis The theory was developed by Immanuel Kant and published in his Universal Natural History and Theory of the Heavens (1755) and then modified in 1796 by Pierre Laplace. Originally applied to the Solar System, the process of planetary system formation is now thought to be at work throughout the universe.  Star formation is a complex process, which always produces a gaseous protoplanetary disk (proplyd) around the young star. The protoplanetary disk is an accretion disk that feeds the central star. Initially very hot, the disk later cools in what is known as the T Tauri star stage; here, formation of small dust grains made of rocks and ice is possible. stars form in massive and dense clouds of molecular hydrogen— giant molecular clouds (GMC). These clouds are gravitationally unstable, and matter coalesces within them to smaller denser clumps, which then rotate, collapse, and form stars.  The Nebular Hypothesis The turbulence causes collection of matter measuring meters across Small chunks grow and collide, eventually becoming large aggregates of gas and solid chunks The Nebular Hypothesis Gravitational attraction causes the mass of gas and dust to slowly contract and it begins to rotate. The dust and matter slowly falls towards the center. Protostar The Sun After sufficient mass and density was achieved in the Sun, the temperature rose to one million °C, resulting in thermonuclear fusion. H atom + H atom = He atom + energy Birth of the Solar System  Protoplanets Gravitational forces allow the inner planets to accrue and compact solid matter (including light and heavy atoms) Solar radiation blew gases (primarily hydrogen, helium) away from inner planets These gases were collected and condensed into the gas giants (Jupiter, Saturn, Uranus, Neptune) Beyond Neptune, ice and frozen gases form Pluto, Sedna and the Kuiper Belt Objects Left-over debris form comets and asteroids Birth of the Solar System  Size of the Planets https://www.youtube.com/watch?v=sCkhE u3lYNc  The Age of the Earth Earth is ~ 4,570,000,000 years old Meteorites give us access to debris left over from the formation of the solar system We can date meteorites using radioactive isotopes and their decay products Geologic Time WHEN LIFE EXPLODED? Geological time scale  Geological time scale  The geologic time scale is a system used by scientists to describe Earth's history in terms of major geological or paleontological events (such as the formation of a new rock layer or the appearance or demise of certain lifeforms).  Geologic time spans are divided into units and subunits, the largest of which are eons.  Eons are divided into eras, which are further divided into periods, epochs, and ages Geologic dating allows scientists to better understand ancient history, including the evolution of plant and animal life. It also helps them learn more about how human activity has transformed the planet. Hadean  The oldest of the geologic eons is the Hadean, which began about 4.6 billion years ago with the formation of Earth and ended about 4 billion years ago with the appearance of the first single-celled organisms. PRIMORDIAL SOUP HYPOTHESIS In the primitive Earth's surface, carbon, hydrogen, water vapour, and ammonia reacted to form the first organic compounds. under prebiotic conditions. The mixture of inorganic and organic compounds with water on the primitive Earth became the prebiotic or primordial soup. There, life originated and the first forms of life were able to use the organic molecules to survive and reproduce. Archean  The next geologic eon, the Archean, began about 4 billion years ago. During this period, the cooling of the Earth's crust allowed for the formation of the first oceans and continents.  Scientists believe that the first single- celled lifeforms developed during the Archean. These tiny microbes left their mark in layered rocks known as stromatolites, some of which are nearly 3.5 billion years old. Proterozoic The Proterozoic eon began about 2.5 billion years ago and ended about 500 million years ago when the first complex lifeforms appeared. During this period, the Great Oxygenation Event transformed the Earth's atmosphere, allowing for the evolution of aerobic organisms. The first multicellular organisms developed during the Proterozoic eon, including early forms of algae. Fossils from this eon are very small. Some of the most notable from this time are the Gabon macrofossils, which were discovered in Gabon, West Africa. The fossils include flattened disks up to 17 centimeters long.  Cambrian period —the earliest part of the Phanerozoic eon—the first complex organisms appeared. Most of them were aquatic; the most famous examples are trilobites, small arthropods (creatures with exoskeletons) whose distinct fossils are still being discovered today.  During the Ordovician period, fish, cephalopods, and corals first appeared; over time, these creatures eventually evolved into amphibians and dinosaurs.  WAIT ! BUT AREN’T WE SUPPOSE TO BE TALKING ABOUT BIOLOGY. WHAT ABOUT CELLS AND THEIR DIFFERENCES? WHERE ARE THE PLANTS IN THIS STORY? LETS’ GO BACK!!!!!!!  Cells are an organism’s basic units of structure and function *The cell is the lowest level of organization that can perform all activities required for life* All cells: - Are enclosed by a membrane - Use DNA as their genetic information The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms  A eukaryotic By comparison, a {  cell has membrane- {  prokaryotic cell is simpler and usually smaller, enclosed and does not organelles, the contain a nucleus largest of which or other is usually the membrane- nucleus. enclosed organelles Plants, animals,  Bacteria and  Archaea are fungi, and all prokaryotic. other forms of life are eukaryotic. Eukaryotic cell (animal cell) Plant cell  Plant cell Plant cells are differentiated from the cells of other organisms by their : 1. cell walls 2. chloroplasts 3. central vacuole  Cell wall A cell wall is an outer layer surrounding certain cells that is outside of the cell membrane All cells have cell membranes, but generally only plants, fungi, algae, most bacteria, and archaea have cells with cell walls. Function of the cell wall : 1. Strenght 2. Shape 3. Protection  Chloroplasts  The chloroplast, found only in algal and plant cells, is a cell organelle that produces energy through photosynthesis.  The word chloroplast comes from the Greek words khloros, meaning “green”, and plastes, meaning “formed”. It has a high concentration of chlorophyll, the molecule that captures light energy, and this gives many plants and algae a green color.  Like the mitochondrion, the chloroplast is thought to have evolved from once free-living bacteria.  Central vacuole The central vacuole is a large vacuole found inside of plant cells. A vacuole is a sphere filled with fluid and molecules inside a cell. The central vacuole stores water and maintains turgor pressure in a plant cell. It also pushes the contents of the cell toward the cell membrane, which allows the plant cells to take in more light energy for making food through photosynthesis. Turgor pressure: Turgor pressure is the force exerted by stored water against a cell wall. As water fills the cells, it pushes against the cell membrane and cell wall, producing turgor pressure  Plants and fungi regulate the turgor pressure in their cells by directing water into the specialized vacuoles.  The vacuoles draw water out of the cytoplasm. This allows the concentration of the cytoplasm to stay consistent, while the water is continually moved into the cell. As turgor pressure builds in the vacuole, it pushes out against the sides of the cell.  Each cell is assembled so their cell walls are pushed together. In this way, each cell in a plant becomes a water filled brick. The cells can be stacked to great heights. Plants can even turn their leaves and stems toward the sun by modifying the turgor pressure in their cells. Finding Order In Diversity 1. Classification 2. Taxonomy 3. Taxon 4. Phylogeny 5. Binomial system 6. Dichotomous key There is a problem with only naming organisms by their common names. What is the name of this organism? Puma Cougar Why is this a problem??? Panther Mountain Lion  When you think of a fish, what characteristics do you think of??? Fins Gills Streamline shape Bones Biologists needed to attempt to give order to the vast number of organisms on earth. This is called Taxonomy. 1. Classification is the grouping of organisms based on similarities of features. 2. Taxonomy is the science of studying classification. It looks at features and tries to arrange them in a logical order.  ‘hierarchical’ means in ascending sequence.  A ‘species’ is the fundamental taxon  Groups of similar species form the next largest taxon called a ‘genus’.  Groups of similar genera form the next largest taxon called a ‘family’  …and so on, up to the largest taxon = Kingdom.  Fucus vesiculosus  Fucus serratus  Enteromorpha intestinalis  Patella vulgata  Balanus balanoides  Actinia equina  Littorina littorea  species – all in lower case Fucus vesiculosus Genus – has a capital letter Italics (or underlined) -to show the words are different to ordinary text.  Panthera leo Panthera tigris Panthera pardus  Canis domestica Canis lupus Common Name : Grizzly Bear Common Name : Polar Bear Scientific Name : Ursus arctos Scientific Name : Ursus maritimus Do Ursus arctos and Ursus maritimus belong to the same species or same genus? Which group, genus or species is most inclusive?  Boa constrictor  Gorilla  Giraffus  Hippopotamus amphibius  Bison bison  Equus zebra  Tyrannosaurus rex  Elephas maximus  The binomial system of nomenclature is the formal system by which all living species are classified (taxonomy)  It was initially developed by a Swedish botanist named Carolus Linnaeus in 1735  It is periodically assessed and updated at a series of international congresses which occur every 4 years  The binomial system of nomenclature provides value because:  It allows for the identification and comparison of organisms based on recognised characteristics  It allows all organisms to be named according to a globally recognised scheme  It can show how closely related organisms are, allowing for the prediction of evolutionary links  It makes it easier to collect, sort and group information about organisms Organisms are grouped by more than 2 names. Every organisms actually has 7 names!!! Each name represents a different level of organization, or taxon. Carl Linnaeus Systema Naturae – 1735 Swedish botanist, zoologist, and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". *GOD CREATED, LINNAEUS ORGANISED*  Most inclusive Kingdom Phylum Class Order Family Genus Species Least inclusive Kingdom Phylum Class Order Family Genus species Taxon Cat Man KINGDOM Animalia Animalia PHYLUM Chordata Chordata CLASS Mammalia Mammalia ORDER Carnivora Primates FAMILY Felidae - cats Anthropoids - apes Genus Felis Homo species cattus sapiens  A dichotomous key is a method of identification whereby groups of organisms are divided into two categories repeatedly  With each sequential division, more information is revealed about the specific features of a particular organism  When the organism no longer shares its totality of selected characteristics with any organism, it has been identified  When using a dichotomous key to identify specimens it is preferable to use immutable features (i.e. features that do not change)  Size, colouration and behavioural patterns may all vary amongst individuals and across lifetimes.  Physical structures (e.g number of limbs) and biological processes (e.g. reproduction methods) make for better characteristics  Dichotomous keys are usually represented in one of two ways:  As a branching flowchart (diagrammatic representation)  As a series of paired statements laid out in a numbered sequence (descriptive representation) TILL NEXT WEEK THE SCIENTIFIC METHOD AN INTRODUCTION RULE No. 1 IN SCIENCE ALWAYS QUESTION EVERYTHING ! Richard Feynman Steps of the scientific method  Using observations, identify a problem you would like to solve Example: When do migratory birds return ? what are the eating habits of bears? This is a question you DO NOT know the answer to and can’t look up. “Why” and “What would happen if..” are good beginnings of scientific questions.  Observation and measurments Uses our senses to gather information Qualitative: uses our 5 senses – The termites follow a circle made with a blue pen on white paper Quantitative: uses numbers – 3 termites follow a circular blue pen line that is 5 cm in diameter  Classification and data managment Graphs pie charts Tables Maps Taxonomy (the branch of science concerned with classification, especially of organisms; systematics) Known species versus unknown species (classification schemes) ( habitat, behaviour , eating habits, mating habits, morphologcal characteristircs)  Remember? Observation Inference Uses our senses to gather A logical interpretation of information events based on prior Qualitative: uses our 5 knowledge or opinion senses – Educated guess – The termites follow a circle made with a blue pen on Termites follow the blue line white paper because the like it. Quantitative: uses numbers – 3 termites follow a circular blue pen line that is 5 cm in diameter Do we use observations or inferences when identifying a problem?  Step 2: Gather Information Use references to do Example: Termites background research – Live underground – Books – Don’t have compound – Journals eyes (can only see light – Magazines and dark) – Internet – TV – Videos – Interview Experts www.goldstarexterminators.net  Step 3: Formulate a Hypothesis Hypothesis Example: Termites Possible answer to a Termites: question that can be tested – I hypothesis that if the based on observations and termites follow a dark colored pen on a dark background knowledge then they follow the dark pen “If” “Then” “Because” on a light background statement because of the color contrast since they see light and dark, but not color. Do we use observation or inference to formulate a hypothesis?  Step 4: Develop an Experiment Materials: Procedure A list of all the things you Step by step instructions need Identifies the variables used Supplies in the experiment How would you describe how to make a Peanut Butter and Jelly Sandwich to someone who had never done it? To someone who didn’t know what peanut butter or jelly is?  Variables: Independent Variable The variable I (the scientist) change or manipulate Examples: – The color of paper under the termites – The color of pen used – The brand of pen used  Variables: Dependent Variable Is measured in the experiment Changes because of the independent variable “Depends” on the independent variable Examples: – Does the termite follow the line (yes/no) – How many termites follow the line (whole number) – How long do the termites follow the line (time)  Variables: Constant All the factors in the Examples: experiments that are kept If you test color of paper, the same keep the color of pen Everything except the constant independent variable If you test the smell of pen, Keeps the experiment ‘fair’ keep the color and type of pen constant (only change smell) The exact termites used The time of day and how long the termites are there The shape of the line drawn  Variable: Control The normal condition that you compare the other conditions to Recreate the conditions you first observed Example: – Termites in a Pitri dish on white filter paper and draw a blue line with a bic pen in the same shape as before.  Step 5: Record and Organize Data Write all observations and measurements Use a table to organize your data – List your independent variable on the left side – Record your dependent variables on the right side If you have more than one dependent variable, use a new column for each dependent variable Independent Variable Dependent Variable: Did they follow the line? Blue ink on white paper Yes/No Blue ink on black paper Yes/No Which one of these independent variables is the control? Which part of the independent variable is the constant?  Step 6: Analyze Data “A picture is worth a thousand words” Compare and look for trends and patterns using graphs  Bar Graph Used for categorical data Number of Termites  Line Graph Number of termites on the ink line for 40 seconds Number of Termites Line graphs are used for time interval data Pie Chart A Pie Chart adds up to a whole – 100% or all of something  Step 7: Make Conclusions You must repeat the experiment to make the data valid You should run your experiment at least 3 times to confirm your results – You can run all the experiments at one time, or run one after the other Each separate experiment is called a Repetition (or Rep).