Module 4: Introduction to Life Science (2nd Grading) Flashcards
It is the hypothesis that LIFE exists throughout the Universe, distributed by space dust, meteoroids, asteroids, comets, planetoids and also by spacecraft carrying unintended contamination by microorganisms.
Panspermia
What does Pan and Sperma mean in Ancient Greek?
- Pan - meaning “All”
- Sperma - meaning “Seed”
Impact-Expelled Rocks from a planet’s surface serve as transfer vehicles for spreading biological material from “one solar system to another.”
Lithopanspermia (Interstellar Panspermia)
Impact-Expelled Rocks from a planet’s surface serve as transfer vehicles for spreading biological material from “one planet to another within the same solar system.”
Ballistic Panspermia (Interplanetary Panspermia)
The intentional spreading of the seeds of life to other planets by an advanced extraterrestrial civilization.
The intentional spreading of the seeds of life from Earth to other planets by humans.
Directed Panspermia
It is the oldest theory that explains the beginning of life.
It shows that life appears from non living things.
It also proposes that the first life-forms generated were very simple and through a gradual process became increasingly complex.
It was the most popular explanation on how life began.
The great majority of learned people believed that animals of all
sizes did not have to have parents.
Abiogenesis (Spontaneous Generation Theory)
A British Philosopher agreed that the spontaneous generation was an acceptable belief.
“To question that beetles and wasps were generated in cow dung is to question reason, sense, and experience.”
Sir William David Ross
An Italian Physician disagreed with this idea and challenged abiogenesis.
He explained through his experiment that life did not came from nonliving things but from living things.
Francesco Redi
An Italian Scientist, who conducted another experiment to Discredit Abiogenesis.
He boiled a broth containing meat and vegetables in clean glass containers.
He concluded in his experiment that life entered in the open flask is the reason life grow.
Abbe Lazarro Spallanzani
Their experiment was based on the proposed type of atmosphere and major elements present in early earth.
Urey-Miller Experiment (Urey-Miller Hypothesis)
They provided proof that Amino Acids and other simple organic matter can be formed with the right ingredients.
Proposed that amino acids can be synthesized outside living systems.
They conducted experiments in which a gas mixture containing; hydrogen, ammonia, methane and water vapor was subjected to electric spark.
It yielded aldehydes, amino acids and carboxylic acids.
Stanley Miller & Harold Urey
This theory suggests that life arose gradually from inorganic molecules, with “Building Blocks” like amino acids forming first and then combining to make complex polymers.
Oparin-Haldane Hypothesis (Alexander Oparin & John Burdon Sanderson Haldane - J.B.S Haldane)
The first life-forms appeared in the warm, primitive ocean.
It obtains nutrients from the compounds in existence on early Earth.
Heterotrophic
It generates food and nutrients from sunlight or inorganic materials.
Autotrophic
It is microscopic spontaneously formed spherical aggregates of lipid molecules that are held together by electrostatic forces and that may have been precursors of cells.
Coacervates
It is the protective layer of the cell from its environment.
In the form of lipids.
Cell Membrane
It is the first formation of a cell.
Lipids
This type of cell cannot survive with an oxygenated environment which is ideal in early Earth.
Cells with No Nucleus.
Anaerobic Prokaryotes
It produced large amounts of oxygen in the atmosphere through photosynthesis in a vast ocean.
It is the oldest life fossil found in a 3.5 billion year rock.
Cyanobacteria (Photosynthetic Eubacteria)
It is the most common bacteria that are found everywhere like disease causing bacteria and bacteria that causes decay.
Eubacteria
