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- Endosymbiotic theory : this states that mitochondria and chloroplast were prokaryotes which became part of the eukaryotes by endocytosis.  (mitochondria and chloroplast have naked DNA and 70s ribosomes just like prokaryotes.)
- Pasteur's experiment : it proved that spontaneous regeneration of life does not occur. (tested by adding nutrient broth to three swan flasks and exposing them to different conditions)
-  Miller and Urey experiment : proved that life was possible many years ago. (created the conditions of earth in a system and found living organisms in the mixture after a while)
- First life on earth was amino acids.

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-Origin of cells that cells come from pre-existing cells that can be cultured in an abiotic environment.
-This is proven through the Miller-Urey experiment where  he created a low oxygen environment, high radiation levels, high temperatures and electrical storms. He proved that non-living synthesis of simple organic molecules were possible. This was proven when some simple amino acids and some oily hydrocarbons were found in the reaction mixture.
-Endosymbiotic theory: Organelles such as mitochondria and chloroplasts were once prokaryotes that were taken in by larger prokaryotes by endocytosis. This can be proven by looking at characteristics of organelles. For example, mitochondria and chloroplasts have 70S ribosomes, have. singular naked DNA, divide by binary fission and are susceptible to some antibiotics. These are all characteristics. similar to prokaryotes.

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- Pasteur's experiment hypothesise that cells come from cells. however, the result shows that spontaneous generation of cells and organisms does not occur.
- the Miller- Urey Experiment proves that cells aren't necessary to come from pre-existing cells. (amino acids in specific condition, cells weren't present at the beginning of the experiment)
- The Endosymbiotic theory states that mitochondria and chloroplast are prokaryotes taken in through endocytosis. They remain in the host cell and provide energy for it. it is supported by the similar characteristics of the mitochondria and chloroplast. they both have 70S ribosomes, divided by binary fission etc.

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Living things do not spontaneously arise from non-living things.
The endosymbiotic theory could possibly show that mitochondrion and chloroplasts could have been prokaryotes before being engulfed by other prokaryotes to form eukaryotes.
Amino acids could have been produced during the early years of the earth (Miller-Urey experiment

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- Pasteur’s experiment
-Origin of cells (cells came from non-living things)
- All cells came from one cell “ancestor “
They had 3 S shaped flasks with nutrients (broth)
The broth was heated to kill all
Microorganisms. One was broken which allowed oxygen to enter.

- Endosymbiotic theory

-  Mitochondria and Chloroplast have their own naked and circular DNA, they have ribosomes similar to  prokaryotes(70s) they transcribe DNA & mRNA to synthesis some proteins.

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Today we learnt :
1. the theory of endosymbiosis
2. the difference between eukaryotic and prokaryotic cells
3. how the spontaneous generation was disproved.
4. why there are enzymes in the mitochondria.
5. life and its origins from the elements
6. the various studies that were conducted that were used to prove or disprove theories
7. The formation of organelles, how prokaryotes and eukaryotes became different through evolution
8. first " life " on earth was simple amino acids, the building blocks of protein

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I have learnt
- that all cells come from other cells
- that cells can come from organic substances
- about Louis Pasteur and Miller Ureys’ experiment
- Louis Pasteur’s experiment showed that cells need to come from other cells. He broiled broth to kill of any living cells and he places it in three setups. He proved that nutrient broth only grows when microbes come into contact with them.
- that the endosymbiosic theory states that eukaryotes are formed from prokaryotes like the mitochondria and chloroplasts. They are in a symbiotic relationship as they benefit eachother.

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- Cells come from pre-existing cells
- In the past, people believed in spontaneous combustion which was the theory which stated that life could appear from a combination of dust and air.
- A microbiologist called Louis Pasteur proved the spontaneous combustion theory wrong through an experiment that ultimately proved that there were microbes on the dust that became organisms we could see.
- Louis Pasteur boiled some broth in a swan neck flasks. He broke the neck of one and left the other unbroken. The broth in the flask where the swan neck was not broken remained clear (no microbes were formed and any microbes from the air were trapped in the curve of the swan neck), while the broth in the broken-necked flask became cloudy, as microbes carried to the flask in the air grew and multiplied.
- The endosymbiotic theory is a theory that suggests that prokaryote cells created eukaryote cells in the past.
- This theory supports the idea that mitochondria and chloroplasts were themselves prokaryotes that were taken in by larger prokaryotes by endocytosis. Instead of being digested and broken down, these cells remained inside the host cells.
Evidence of this would be:

- Both have a singular, naked DNA

- Contain 70S ribosomes (like in prokaryotes)

- The divide by binary fission (like prokaryotes)

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- Louis Pasteur's experiment (Pasteur had 3 swan-neck flasks containing boiled meat broth: one kept upright, one tilted and one with their flask broken - only microbes produced in the tilted and broken flasks) disproved the idea of spontaneous generation.
- Miller and Urey recreated the initial atmosphere of earth and showed that non-living environments can create simple compounds (the Miller-Urey experiment showing how cells originated).
- Symbiotic relationship, also known as mutualism, is when there is mutual benefit present.
- Endosymbiotic theory states that eukaryotes formed from prokaryotes, such as the mitochondria (forming from the engulfing of a heterotrophic bacteria) and chloroplasts (formed from engulfing of a phototrophic bacteria).
- Mitochondria and chloroplasts exhibit prokaryotic features such as reproduction by binary fission and contain 70S ribosomes.
- Mitochondria and chloroplasts have their own genetic material (separate from nucleus' genetic material), eg. mitochondria produces its own enzymes which is required in respiration to produce ATP.

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-  Louis Pasteur's experiment supports the hypothesis that cells from come pre-existing cells
- Theory of Spontaneous generation states that life could appear from a combination of dust air and other factors.
- 4 conditions are needed for life to come about
- The endosymbiotic theory which tells us how eukaryotes are formed from prokaryotes. Prokaryote cells that release ATP evolved into mitochondria and Prokaryote cells that could convert light energy to chemical energy evolved into chloroplast.
- Chloroplast and Mitochondria have their own DNA apart from the DNA present in nucleus.
-  Mitochondria and chloroplast have similar features as prokaryotes:
1. 70s ribosome
2. Divide by binary fission
3. Singular naked DNA

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I understand that
- endosymbiosis occurred in prokaryotes, which led to the formation of eukaryotes
- endosymbiosis is still occurring today (eg. in termites where prokaryotes live, probiotics in our intestines)
- spontaneous regeneration does not exist
- the theory of spontaneous combustion occurred when microorganisms were found on dirty clothes in a room that was not entered for a span of
- the first form of life was the amino acid
- formation of DNA is crucial to formation of cells
- it is definitely true that cells come from pre-existing cells (Louis Pasteur experiment)
-  prokaryotes and eukaryotes are different in terms of presence of nucleus and double membrane structure

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-Pasteur's experiment shows that there is no spontaneuos generation occurs in Earth
-cell theory includes:
All living thing composed of cell(s)
Cells come from per-existing cells
cells are the smallest unit of life
-genetic code is universal each of the 64 codons (codon is combination of 3 DNA bases)
- the evidences of endosymbiotic theory:
1.mitochondria and chloroplast have ribosomes in the size of70S
2.mitochondria and chloroplast have naked DNA just like prokaryotes
3.they are divided by binary fission
-endosymbiotic theory is supporting the theory that mitochondria and chloroplasts were themselves prokaryotes that were taken in by the larger prokaryotes by endocytosis
-Miley-Urey experiment

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I understood that:
- the endosymbiotic theory occurs when both parties in the relationship benefit from it. An example would be the honey bee and the flower. The flower gets pollinated while the honey bee can retrieve nectar in the process of pollination. The endosymbiotic theory is still prevalent in today's context as there are still cells in the termite, for example, which enable the organism to digest wood.
- two scientists came together to investigate how cells originated in the beginning of time and this was coined the Miller-Urey experiment. This experiment consisted of them creating an atmosphere that was similar to that in ancient times and they observed how there was a settlement of liquid on the bottom of the collecting apparatus and it was later identified as amino acids. This suggests that the earliest organisms started from amino acids.
- The term 'spontaneous generation' was used a long time ago and cells were believed to have occurred on their own
- A prokaryote lacks a nucleus and a double-membrane structure while a eukaryote has both a nucleus and a double-membrane structure

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- The origin of cell, has been an age long question that has baffled biology for a long time.
-There was a period in time where spontaneous generation was accepted as the basis of life
-This meant that life just miraculously appeared from non living things, life dust etc.
-This was disproved by Louis Pastuer, where he took a broth and boiled it, while excluding the entrance of air into the swan neck flask. He then let the swan neck flask sit for 3 years, and no form of life was present within the flask.
-Then there was a question of how did the first cell come about. Miller and Urei proved that the first forms of life can be accounted to non living materials having the ability to create life.
-We also learnt that the formation of DNA was before the development of the first cell.
-We then discussed endosymbiotic theory.
-Symbiotic means to work in harmony
-Endosymbiotic theory states that the evolution of eukaryotic cells can be traced back to the development of prokaryotic cells.
-There are 3 types of prokaryotic cells, ones that can produce ATP through oxygen, ones that can produce energy through light, and ones that survive by engulfing the other 2 types of prokaryotes.
-The prokaryotes that engulf, can account for the formation of mitochondria and chloroplasts.
-Mitochondria and Chloroplast have there own genetic material and can reproduce individually via binary fission.
-Organelles like these have the characteristics of prokaryotic cells as they have 70s ribosomes, have naked DNA and reproduce through binary fission.

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- By cell theory, all cells arise from pre-existing cells...what about the first cell?

- The origin of cell/life has been through different theories  the first one being
[spontaneous generation]
- Spontaneous generation states that living things arise form non-living materials in the environment.
- It is disapproved by Louis Pasteur who conducted the Swan-Neck Broth experiment, in which only the sample of nutrient both that contact with the air began having traces of living micro-organisms.
- Later on, the Miller-Urey experiment, involving inorganic substances in water exposed to electric, high radiation, and repeated heating and cooling processes, proved that simple organic molecules such as amino acids, carbohydrates, and fatty acids can be formed from inorganic materials.

- the Endosymbiotic theory states that mitochondria and chloroplast may have been the result of a kind of prokaryotic cell being engulfed by a larger heterotroph prokaryote.
- This arose form similarities between the two organelles and prokaryotic cells;
1. 70s ribosomes
2. They have their own DNA
3. They can divide themselves through binary fission.

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Endosymbiotic theory
- mitochondria and chloroplast were prokaryotes
- taken in by larger prokaryotes during endocytosis
- cell was not digested and remained inside the larger prokaryote
- carried out aerobic respiration and provided energy to host cells
- host cells evolved into mitochondria

Emergence of life
- amino acids are the basis of life
- form RNA and DNA
Pasteur's theory
- swan flasks
- spontaneous generation of cells and organisms does not occur on earth
- conditions on earth do not generate the process
Miller-Urey experiment
- reducing atmosphere + high radiation levels + high temperatures + electrical storms
- water was boiled, gas was added and the electricity was introduced
- steam was condensed
- After running the experiment for a week, some simple amino acids were found in the water
- proves that the synthesis of simple organic molecules was possible