Final Review Flashcards
(154 cards)
First Life form on Earth
The first cellular life was organisms that had little to no oxygen present.This means that they were anaerobic. It was most likely a single cell named Cyanobacteria. These organisms were very small in size which indicates that they were prokaryotes. These cells were most likely to be heterotrophs.
Biology
The study of all living things. All living things are made up of organic compounds
6 Characteristics of living things
Cells, Energy use, Homeostasis, Reproduction, Growth, and Organisation.
Cells
all living organisms are made up of cells, they are small meaning large multicellular organisms have many of them.
Organization
Living organisms are very organized molecularly and on cellular levels. They all have specific stitch tires that have specific functions. And their cells are grouped and organized by the function they do.
Energy use
All living organisms use energy to metabolize which is a chemical process that occurs in the organism. Energy is also used to grow and reproduce.
Homeostasis
All living organisms need to maintain a stable internal condition. A cell in a living organism controls water content by taking it in or releasing it.
Reproduction
All living organisms are able to reproduce sexually (2 parents), or asexually (1 parent.)
Growth
All living organisms grow and they result with cell division and cell enlargement.
Biogenesis
Biogenesis is saying that all living things have to come from another living thing.
Spontaneous Generation
Spontaneous generation is when others thought that living things could come from nonliving things.
-An example of this would be maggots appearing on dead flesh, did they come from the rotting flesh?
-Another example is why fish were in ponds that had been dried up the previous season. How did they come to be in the pond, did they arise from the mud under the pond?
Redi
Jar filled with meat covered with netting (italian)
Redi’s experiment in 1668 was about observing flies after he noticed the different developmental forms of flies. He observed that small maggot-type insects turned into sturdy oval cases. These cases will eventually have flies emerge from them. Redi also looked at maggots and how they seemed to show up where many adult flies had landed before. His observations made him question if flies were actually spontaneously generated from rotting meat or flesh. Redi created an experiment to test his theory that meat that had no adult flies contaminating it would also keep free of maggots. He covered jars filled with meat with a type of netting and filled other jars with meat and no netting over top.
Spallanzani
Meat Broth in flask (italian)
Lazzaro Spallanzani created an experiment to test the hypothesis that spontaneous generation in fact did occur in microorganisms. He hypothesized that microorganisms were not formed in the air like some thought, but that they were formed from other microorganisms. He knew that they grew well in food so he decided to test how they grow in a flask filled with meat broth. Spallanzani had thought that even though they grow in food very well, if he boiled the bone broth all the microorganisms would be killed in and on the flask. He filled up multiple flasks with broth and boiled them until they were steaming. He then closed half of the flasks and left the other half of them to stay open. The broth that was sealed remained clear and didn’t have any microorganisms inside. The flasks that were left open became cloudy and filled up with microorganisms again. In conclusion of his experement he believed that boiled broth only became contaminated by the microorganisms in the air that entered into the flask.
Pasteur
Meat broth in flask with curved neck. (French)
In the 1800s the idea that spontaneous generation existed was very controversial, and the Paris Academy of Science offered a prize to whoever could clear up whether or not spontaneous generation was a thing. Louis Pasteur accepted the challenge and won the prize. He made a flask with a curved neck on it that still allowed air to flow into the flask. But it wouldn’t allow for microorganisms and other particles to flow into it. The body of the flask was filled with bone broth and boiled and then sat for a year and the broth always stayed clear and never got cloudy. After a year Pasteur broke off the neck of the bottle exposing the broth to air and all the particles within it. The next day the broth had become cloudy and was infested with microorganisms. Pasteur concluded that this was caused by the microorganisms in the air. This ended the theory of spontaneous generation.
Anaerobic
Cells that require none or very minimal oxygen gas.
Aerobic
Cells that require oxygen gas.
Prokaryotic Cells
A single cellular organism that doesn’t have a nucleus and membrane-bound organelles.
Eukaryotic Cells
A cell that does have a nucleus and membrane bound organelles.
Autotrophs
An organism that uses energy to combine and create organic molecules from inorganic substances
Heterotrophs
An organism that acquires organic food molecules by eating other organisms or their by-products
Lynn Margulis and how the first eukaryotes evolved
In the late 1900s, Lynn Margulis proposed what might have started as an invasion became a successful and beneficial relationship called Endosymbiosis. This relationship is beneficial for both parties. She thought that the aerobic (cells that require oxygen) prokaryote eventually gave rise to the modern mitochondria.
Evidence that shows mitochondria were once free-living cells.
The mitochondria (and chloroplasts) replicate independently from the rest of their cell. The mitochondria (and chloroplasts) also contain their own genes that are different from the genes within their cells. These genes are found within the mitochondria (and chloroplasts) in a circular piece of DNA, they are arranged with characteristics of prokaryotic, although not eukaryotic DNA.
Nicolaus Sterno
Law of superposition in 1669 (Danish)
He stated that many layers of rock and soil were created on top each other by water and wind. The layer at the bottom was the oldest and the layer on the top would be the newest. His theory helps give the history of Earth.
Jean Baptiste de Lamarck
Theory of evolution (French)
Hypothesized that traits acquired over a lifetime are passed onto offspring. It also hypothesized that structures could be formed through repeditive use and structures could be lost through lack of use.
