BELLRINGER Silently write the learning targets at the
BELLRINGER Silently write the learning targets at the top of your notebook page Date: 09/27 – 9/28 Topic: Origins of Life Learning Target: Compare different theories about how life originated on earth Answer the Following Question: • When meat stays outside for a long time, maggots appear. Did these maggots come from the meat? Why or why not?
Homework Research analogous vs. homologous structures Write the definition and an example of each Due next Class!!! Homework is 20% of your grade!!!!
Unit 2 : Evolution Day 1 Day 2 Day 3 Day 4 What are some beliefs for how life on Earth first started? What is some evidence that tells us organisms evolved over time? How does this apply to us Humans? What is N. Selection How mutation Test Natural Modeling and genetic Day!! Selection and recombination practicing increase scenarios genetic variation? Hominid Evolution Day 5 Day 6 Test: Review Packet HW Day 7
Agenda • • Bell Ringer (5 minutes) Introduction (10 minutes) Notebook Input (10 minutes) Notebook Output (5 minutes) Group Stations (40 minutes) Independent Practice (15 minutes) Exit Quiz (10 minutes)
Abiogenesis: believes that life can arise from nonliving things Biogenesis: believes that every living thing came from another living thing
How Did Life Start? Welcome to the journey…
1 st: An old theory…. .
Contribution: Pasteur – disproved the entire theory Of Spontaneous Generation by proving that bacteria exists in the air. Br Of oke t the he fla neck sk! Problem: We still did not know where life came from? Life needs water and oxygen!
nd 2 : Primordial Soup Theory…
CONTRIBUTION: MILLER AND UREY EXPERIMENT, 1953
Endosymbiosis Theory • Dr. Lynn Margulis was the first to claim the endosymbiont nature of mitochondria and chloroplasts with a handful of conclusive evidence.
HMMM? ? • So what kind of organisms must have lived on Earth first? • There was no oxygen until the rise of photosynthetic organisms • The first organism must have been prokaryotic, anaerobic and derived from inorganic (non-living) compounds must have combined with water vapor in to form water.
Ancient form of photosynthesis – used H 2 S instead of H 2 O Stromatolites (cyanobacteria) changed that by utilizing the little H 2 O vapor which released the oxygen; led to modern day photosynthesis. O 2 → ozone layer → Oxygen in troposphere → more life, BOOM!
Theory What is it? Experiment Contribution Problem Spontaneous Generation Life spontaneously Generated from the matter around us (Meat + Flies) Pasteur: Flask with broth was boiled: open flask = bacteria, closed flask= NO bacteria Proved that We did not bacteria exists know where in the air life came from. Life needs water and oxygen! Primordial Soup Miller and Urey: simulated the conditions thought to be present on the early Earth, used it to create amino acids (organic molecules/building blocks of life) Proved that inorganic molecules can create organic molecules (amino acids) Endosymbiotic Eukaryotes obtained their organelles by engulfing prokaryotes Aerobic and photosynthetic bacteria was engolfed (eaten) by another cell, turning Explain how mitochondria, chloroplast and complex cells arose Scientists were not able to turn those amino acids into more complex molecules
Origin of Life Stations v. You will rotate with your group to 4 different stations v. At each station you will have 5 minutes v. Follow the instructions at the station v. Do not leave your group v. NO CELLPHONES! v. Voice Level: Partner Voice v. Do not open the faucets v. Not following directions above will earn you an F
Independent Practice SILENTLY and INDEPENDENTLY answer the questions on your independent practice worksheet Work with urgency! 10 minutes for 7 questions! 10 minutes End
Exit Quiz Create a paragraph using at least 4 vocabulary words below that summarizes each of theories that contributed to the origin of life ( spontaneous generation and endosymbiotic theory) and the experiment that contributed to the discovery of the first organic molecules. Make sure you explain the vocabulary words that you choose to use. 5 minutes Spontaneous generation(abiogenesis) ammonia endosymbiotic theory Miller-Urey water Louis Pasteur hydrogen organic molecule Redi Start like this: Today I learned about 3 major theory’s that explain the origin of life.
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