exam 1 Flashcards
(32 cards)
What are the six attributes of life?
(GOCERR) Grow order consume energy evolve reproduce Response to Environment
What are abiotic entities that have each of the 6?
Growth: Volcano Order: crystal Consume Energy: fires Evolve: computer virus Reproduce: virus Environment: solar panels
what entails higher intelligence.
self-awareness, critical thinking/higher problem solving, religion, abstract thought, math, art, fashion, politics., Transmit and receive signals from interstellar distances, Tendency to control the environment
Drake equation and be able to provide some relevant parameters. What are the potential implications of Drake equation calculations.
- Framework that has both positive and negative for trying to answer the question of are we alone in the universe/galaxy
- A statistical argument, but not a good argument
What is unique about the octopus brain?
- it’s dispersed throughout its tentacles
- two thirds of the animal’s neurons are in its arms
Understand how the notion of infinity would impact our estimates of life in the universe.
- it would essentially provide infinite opportunities for life to exist (including intelligent life)
- If I buy an infinite amount of lottery tickets, then I will win trillions and trillions of times
Be able to address Olber’s Paradox.
- If every line of site ends in a star, why is the sky dark at night? The riddle is known as Olbers’ Paradox
- Since the universe is relatively young, the light from the most distant stars has not reached us.
- If you looked far enough, you would always see a star in the galaxy
What is the observable universe?
A spherical region of the universe comprising everything that can in principle be observed from Earth, given the age of the universe and the amount of time needed for the light from distant objects to reach us.
What are the main constituents of a cell?
water, inorganic ions, and carbon containing molecules
Why do we think carbon is essential to life? Know both arguments for carbon and against silicon.
- Carbon makes stronger bonds than alternative versatile elements, like silicon
- On Earth’s surface, silicon is 1000x more abundant than carbon. Yet all life on Earth is carbon-based. This makes us think that there is something special about carbon.
Know the basic molecules that comprise life.
PLCN (Please lord capture nazis) Proteins (amino acids) Lipids (fats) Carbohydrates (sugars) Nucleic Acids (DNA)
What is meant by the chirality of a molecule and how does that tie into the origin of Life?
- Mirror images- almost the same but not
- We were made out of left handed amino acids
- Means we broke off of a similar ancestor
- We came from one original point
Specifically where do we find sulfur?
Sulfur deposits are found naturally in areas around hot springs and in volcanic regions. It is also widely found in nature as iron pyrites.
What is the “7th” essential element? Where is it used?
- Selenium
- Selenium can replace sulfur in some cases
Why is arsenic poisonous? What was faulty about the Mono Lake experiment? What would be the implications if arsenic based life was discovered?
- They looked at an organism in the lake that was just immune to arsenic, but they thought that arsenic could replace phosphorus
- The implication would have been that arsenic could replace phosphorus and we could create life with arsenic, but we cannot
When did the planet earth form?
4.5 billion years ago
Late heavy bombardment?
Around 4 billion years ago, material left over from planet formation slammed into Earth. These bombardments may have brought water to the young planet.
When do we estimate that life arose on our planet and how do we go about narrowing that down? Know the different lines of evidence.
- Life formed about 4 billion years ago. Oldest evidence is stable isotope anomalies about 3.8 billion years ago.
- Has to have been after 4.2 GYA and before 3.5 GYA
When do we estimate that life arose on our planet and how do we go about narrowing that down? Know the different lines of evidence.
- Life formed about 4 billion years ago. Oldest evidence is stable isotope anomalies about 3.8 billion years ago.
- Has to have been after 4.2 GYA and before 3.5 GYA
- Shark Bay Australia looks like life when it started/ they have stromatolites
What is ALH84001? What are its implications?
- Fragments from a martian meteorite
- Possibly bringing life from Mars (panspermia) because life can survive deep within the rock (?)
- If there was life - then lead to chirality (of amino acids)
- Possibly not the same origin of life, which is a huge deal
- (It’s hard to see whats a fossil on mars and what’s life)
Describe the Miller-Urey experiment. What did they do? What were its results? What did it prove?
- 1950s experiment that used the theory that Earth’s earliest atmosphere should have been oxygen-free and they hypothesized that sunlight-fueled chemical reactions could have led to the spontaneous creation of organic molecules.
- They started making very simple molecules
- Hitting them with a spark
Explain the RNA world hypothesis? What attributes of RNA make it a likely candidate for the earliest forms of life?
- Chains of RNA may have been the first thing to replicate and evolve
- Candidate for life: RNA can start their own replications or creations of proteins
- Can create cell
- Mutations in RNA produce ribozymes which guide chemical reactions in their environment
Explain the steps necessary to go from a prebiotic soup to the first protocell.
- Lab experiment: amino acids are placed in liquid water on a type of a clay surface thought to exist in early Earth.
- Result: RNA chains naturally generate on the clay. Some of these develop membranes around them and peel off the clay
- RNA can naturally form (in a short time) and create the makings of a cell wall
- Start with soup (methane, immonia, cyanide… ) and Spark to create RNA molecules
- Cycle of freeze thaw or clay catalysts to increase molecules to create self replicating RNA
- RNA insert into lipid membrane
- Replace RNA and DNA with proteins
What is a cell? Why is it important to life?
- They are the basic structures of all living organisms
- They take in nutrients and carry out functions necessary for life
- They are the building blocks of life, the smallest unit of life that can replicate independently
- All cells have a membrane that separates the outside world from the living matter inside
- Cells contain hereditary information that are transmitted to the next generation of cells
