Running Head: GEOMICROBIOLOGY HOMEWORK
1
Geomicrobiology
Student's Name
Course Name and Number
Instructor's Name
Assignment Due Date
, GEOMICROBIOLOGY HOMEWORK 2
Geomicrobiology
Homework
1. (10 points) Both methanogens and cyanobacteria are autotrophic, which one do
you think is more likely to be found on Mars and why? Hints: Consider the
presence of water, types of rocks on Mars.
I think methanogens are more likely to be found in mars. The reason is that they live
in marshes and swamps and use hydrogen as their source of energy. Besides,
methanogens are non-photosynthetic, do not require oxygen and can survive extreme heat
which makes them ideal for surviving on Mars.
2. (10 points) What are some evidence for and against the biogenicity of Earth’s
oldest trace fossils preserved in oceanic crust? (Lecture 13)
Some of the proof of biogenicity of Earth’s fossils preserved in the ocean crust
includes the tubular textures, spiral textures and granular textures observed in the ocean
crust. Besides, abiotic glass alteration was also observed in the ocean crust.
One of the evidence against the biogenicity is that the samples lacked chemical
biomarkers. The other evidence is that it was hard to find the most distinctive signature
fossils. Also, apparent titanite replacement and crustal ages differ substantially.
3. (10 points) Give three types of extremophiles (including names) and describe
what extreme conditions they are resistant to?
The first type of extremophile is known as acidophilus and it includes some bacteria,
archaea, and eukaryotes. Acidophiles use both active and passive specialized mechanisms
to regulate their levels of pH. The passive mechanisms involve the secretion of biofilm to
prevent molecules from diffusing into the cell. The second type is alkaliphiles whose pH
1
Geomicrobiology
Student's Name
Course Name and Number
Instructor's Name
Assignment Due Date
, GEOMICROBIOLOGY HOMEWORK 2
Geomicrobiology
Homework
1. (10 points) Both methanogens and cyanobacteria are autotrophic, which one do
you think is more likely to be found on Mars and why? Hints: Consider the
presence of water, types of rocks on Mars.
I think methanogens are more likely to be found in mars. The reason is that they live
in marshes and swamps and use hydrogen as their source of energy. Besides,
methanogens are non-photosynthetic, do not require oxygen and can survive extreme heat
which makes them ideal for surviving on Mars.
2. (10 points) What are some evidence for and against the biogenicity of Earth’s
oldest trace fossils preserved in oceanic crust? (Lecture 13)
Some of the proof of biogenicity of Earth’s fossils preserved in the ocean crust
includes the tubular textures, spiral textures and granular textures observed in the ocean
crust. Besides, abiotic glass alteration was also observed in the ocean crust.
One of the evidence against the biogenicity is that the samples lacked chemical
biomarkers. The other evidence is that it was hard to find the most distinctive signature
fossils. Also, apparent titanite replacement and crustal ages differ substantially.
3. (10 points) Give three types of extremophiles (including names) and describe
what extreme conditions they are resistant to?
The first type of extremophile is known as acidophilus and it includes some bacteria,
archaea, and eukaryotes. Acidophiles use both active and passive specialized mechanisms
to regulate their levels of pH. The passive mechanisms involve the secretion of biofilm to
prevent molecules from diffusing into the cell. The second type is alkaliphiles whose pH
