WorksheetsAstrobiology
Total questions: 19
Worksheet time: 10mins
A biosignature is...
a chemical that can indicate the presence of life
a place where life can exist
a type of life that does not require oxygen
a living thing that can survive extreme conditions
Animals need oxygen, but many bacteria and microscopic organisms do not. This is because
oxygen helps cells turn food into energy, and larger bodies and brains need lots of energy
oxygen helps cells turn food into energy, and larger bodies and brains do not need lots of energy
carbon dioxide helps cells turn food into energy, and larger bodies and brains need lots of energy
animals can also use chemosynthesis to generate energy
What is one reason we might not recognize life if we find it?
It could have oxygen as a biosignature.
It could have carbon dioxide as a biosignature.
We might not know what to look for, especially if it is very different from Earth life.
It could have complex carbon molecules as a biosignature.
Extraterrestrial (alien) life is likely to be different from Earth life because...
Earth-sized planets in the habitable zone are abundant in the universe
we lack the technology to recognize some potential biosignatures
the conditions on other planets are different from conditions on Earth
it could have oxygen as a biosignature.
Some scientists believe life is abundant in the universe because...
the conditions on other planets are different from conditions on Earth
the chemicals life is made of are abundant in the universe
all life requires liquid water
all life requires a source of energy
Some scientists believe life is abundant in the universe because...
we lack the technology to recognize some potential biosignatures
life arose on Earth soon after the planet formed
all life requires liquid water
all life requires a source of carbon
Phosphine is a biosignature of...
life that does not require carbon
life that does not require liquid water
life that does not require a source of energy
life that does not require oxygen
On Earth, we know of life that can survive without...
carbon
oxygen
liquid water
a source of energy
Some scientists believe life is abundant in the universe because...
we lack the technology to recognize some potential biosignatures
Earth-sized planets in the habitable zone are abundant in the universe
all life requires liquid water
all life requires a source of energy
What are spectra?
complex molecules like proteins
"fingerprints" that indicate the presence of specific gases in a planet's atmosphere
methods used by organisms for obtaining energy in places with no sunlight.
types of life that do not require oxygen
All life as we know it requires...
silicon, carbon, and a source of energy
liquid water, carbon, and a source of energy
oxygen, carbon, and a source of energy
phosphine, oxygen, carbon, and a source of energy
All life as we know it requires... (CHECK ALL CORRECT ANSWERS)
carbon
a source of energy
liquid water
oxygen
non-extreme environments
Chemosynthesis is
obtaining energy from sunlight; often used by plants
obtaining energy from chemicals; often used by microscopic organisms that life in the dark
obtaining energy from eating other organisms; often used by large, complex animals
_________________________ is a very inefficient way of obtaining energy, so it cannot power complex life, only single-celled organisms.
photosynthesis
chemosynthesis
It is highly unlikely that we will find animals that get their energy from
chemosynthesis
eating other animals
eating plants
_________________________ is a method used by microscopic organisms for obtaining energy in places with no sunlight.
photosynthesis
chemosynthesis
eating other organisms
Planets around red dwarf stars might NOT have life because
red dwarf stars are smaller and cooler than our sun
red dwarf stars last a long time, giving life a long time to evolve
red dwarf stars put out bursts of dangerous radiation
red dwarf stars explode a lot
Planets around red dwarf stars might have life because
red dwarf stars are smaller and cooler than our sun
red dwarf stars last a long time, giving life a long time to evolve
red dwarf stars put out bursts of dangerous radiation
red dwarf stars explode a lot
Carbon is a building block of all life as we know it because
carbon is always present where there is liquid water
very complex molecules, like proteins, can be made from carbon
carbon can protect proteins from denaturation
carbon is always present at just-right temperatures
