ASTR Life in the Universe Midterm Exam 2

According to current astronomical data, roughly how old is the Universe

14 billion years

According to geological data, earth is how old?

4.5 billion years

order of events:

4.5 billion years ago: the earth formed 3.5 billion years ago: earliest known life on Earth 2 to 2.5 billion years ago: start of GOE 550 million years ago: the Cambrian explosion 2 million years ago: the first hominids evolve

Radio signal from aliens saying" we just received your message from 1939" how far away are they

40 lightyears away

what conditions do scientists suspect caused the sudden Cambrian explosion

All of the above: -organisms became sufficiently complex that more diversity became possible -oxygen reached critical levels necessary to support complex life -climate changes led to the end of snowball Earth

In Contact, what is the name of Hadden's adult theme park?

Babylon

the formation of the universe occurred with an event called the:

Big Bang

In Contact, what major character was killed by sabotage of the Machine?

Drumlin

What is the solution to the faint young sun problem

Earth's early atmosphere had more greenhouse gases than today's atmosphere

According to inorganic carbon cycle, if the amount of CO2 in the atmosphere gets too high

Earth's temp warms, which leads to more rainfall, which converts CO2 into limestone, reducing the amount of CO2 in the atmosphere

Contact characters:

Ellie Arroway- discovered the Message Xi Qiaomu- archaeology Devi Sukhavati- microbiology and astrobiology Vaygay Lunacharsky- russian physicist Abonnema Eda- discovered superunification, the Theory of Everything

the fact that Earth had liquid water and life 3 billion years ago even though the Sun back then had a lower energy output is known as the...

Faint Young Sun Problem

who was burned at the stake in 1600 for suggesting that there might be an infinite number of inhabited worlds in the universe

Giordano Bruno (Italian monk)

which of the following elements was created during Big Bang

Helium and Hydrogen

why can't Earth's water have been on the planet since it formed

High temps and constant bombardment by meteors and planetesimals on the early Earth would have driven any water away

the main chem building blocks of life are C, N, O, and Fe (iron) where are they created?

In nuclear reactions inside stars and exploding stars

which planet has a day/night cycle that lasts 24 hours and 37 min

Mars

contact characters

Palmer Joss- Christian preacher who converted after struck by lightning Ted Arroway- Ellie's father John Staughton- Ellie's step-father Ellie Arroway- radio astronomer and hear of Project Argus David Drumlin- Ellie's first graduate advisor and a highly-respected astronomer known for belittling his colleagues

first true life carried genetic info in...

RNA

Which planets could have methane ice?

Saturn, Uranus and Neptune

based on the cosmic calendar, roughly when did the Sun and the SS form

September 1st

which school of ancient greek thought dominated European science form the Macedonian Empire through the Middle Ages?

The Aristotelian

Ancient Greek school of thought who believe that heavens were made of the same substances than the Earth, so there could be many inhabited worlds in the heavens

The Atomists

In contact, which star is message from

Vega

what happened during Cambrian explosion?

a great variety of complex multicellular life arose

Krypton 85 has a half life of 11 years. Krypton planet explodes in 1945. In 1978, kryptonite to disable superman. How much of the original krypton 85 is left in the chunk of kryptonite

an eighth of it

last common ancestor of all life on earth was most likely closely related to ...

archaea living near deep sea thermal vents

Where did the Earth's present day water most likely come from

asteroids

The science of determining the conditions needed for life, searching for those conditions, and searching for life elsewhere is called

astrobiology

the first life on Earth is most likely to have originated

at deep sea ocean vents

humans and other great apes evolved from lesser primates. Most primates have tails, while great apes do not. According to Darwinian evolution, which of the following must be true

at some point in the past, the absence of a tail provided a slight survival or reproductive advantage for the ancestors of the great apes

origin of life

biogenesis

what info about origin of life came from Murchison meteorite

building blocks of life were common in the early solar system

Organisms that have evolved to survive under severe environmental conditions

extremophiles

True or False: evidence for nebular theory of planet formation is rarely around young stars

false

True or False: if Mars has any water ice left today, it is buried deep beneath the Martian surface and is not accessible

false

A .... is any evidence of past life

fossil

what is a piece of evidence that chloroplasts used to be independent cells incorporated into eukaryotic cells

have their own DNA different to the DNA in cell nucleus

wotf is true concerning humans and Darwinian evolution

humans and chimpanzees share a common ancestor

Geologists call the type of rock that form from cooling and solidification of magma:

igneous rock

first cell-like membranes on Earth were likely

lipids in water that self organized into spheres

Suppose a large asteroid were to hit Earth tomorrow, blasting bacterial rocks into space. If one of those rocks were to impact an icy moon and contaminate its pristine subsurface ocean with living organisms, we would call the process:

lithotranspermia

Curiosity mission has discovered that what planet was once warm enough to sport liquid water on its surface

mars

When two continental plates collide on the Earth's surface, what feature is most likely to form

mountain range

long neck giraffes develop because

natural selection

main mechanism of change in Darwinian evolution

natural selection

where would any life on europa and enceladus most likely be found

near underwater hydrothermal vents

what is one necessary but not sufficient condition to be called "life"

necessary for life to reproduce, but not sufficient as seen in a prion

How many species of humans exist on Earth today?

one

wotf is a leading hypothesis about how Earth got its organic molecules?

organics were brought to the Earth by comets and asteroids

potassium 40 radioactivity decays to argon 40 with a half life of 1.3 billion years, which is parent/daughter

potassium is parent isotope and argon is the daughter isotope

In Contact, what was the first clue that the Message was from an intelligent civilization and not from a natural source of radio waves?

prime numbers, they do not occur naturally in nature

When an unstable element decays spontaneously into another element, we call it

radioactivity

geologists determine the structure of earth's interior by using

seismic wave data

natural selection in humans today

sickle cell amenia

why don't scientists believe silicon based life could exist

silicon bonds are weaker than carbon bonds, so complex molecules are fragile

the abiotic (non-biological) carbon cycle:

stabilizes Earth's temperatures over long periods of time

oldest known fossil on life on Earth

stromatolites

what type of planets formed from dust that had lost its gooey, icy outer coating, when SS was created

terrestrial planets

...so why aren't prions considered to be living organisms

they don't have genes, so they cannot undergo Darwinian evolution

what has happened to most of the CO2 outgassed by volcanoes over Earth's history

transformed into limestone and other carbonate rocks