1) A cellular structure that is visible with an electron microscope but not with a light microscope is a) a nucleus. b) a ribosome. c) a chloroplast. d) a mitochondrion. 2) Several environments in which you are more likely to find archaea than bacteria are a) fresh water, hot springs, basic environments, and phosphorus-containing environments. b) salt water, hot springs, acidic environments, and sulfur-containing environments. c) fresh water, hot springs, basic environments, and sulfur-containing environments. d) salt water, hot springs, acidic environments, and phosphorus-containing environments. Solution 1. Nucleus, chloroplast and mitochondria are visible under a light microscope. But the detailed study of these structures requires an electron microscope. Ribosomes are still smaller structures that are present in the cytoplasm. They are visible only under an electron microscope. Therefore, option B is correct. 2. Archaea is the organism which lives in extremely harsh environments like marshlands, oceans, hot springs, salt lakes. They are also found in sulfur springs or deep sea thermal vents. This is because they can sustain higher temperatures and pH levels that of sulfuric acid. Therefore, option B is correct. Archaea are mostly found in salt water, hot springs, acidic environments, and sulfur containing environments..

1. 1) A cellular structure that is visible with an electron microscope but not with a light microscope
is
a) a nucleus.
b) a ribosome.
c) a chloroplast.
d) a mitochondrion.
2) Several environments in which you are more likely to find archaea than bacteria are
a) fresh water, hot springs, basic environments, and phosphorus-containing environments.
b) salt water, hot springs, acidic environments, and sulfur-containing environments.
c) fresh water, hot springs, basic environments, and sulfur-containing environments.
d) salt water, hot springs, acidic environments, and phosphorus-containing environments.
Solution
1. Nucleus, chloroplast and mitochondria are visible under a light microscope. But the detailed
study of these structures requires an electron microscope.
Ribosomes are still smaller structures that are present in the cytoplasm. They are visible only
under an electron microscope.
Therefore, option B is correct.
2. Archaea is the organism which lives in extremely harsh environments like marshlands, oceans,
hot springs, salt lakes.
They are also found in sulfur springs or deep sea thermal vents. This is because they can sustain
higher temperatures and pH levels that of sulfuric acid.
Therefore, option B is correct.
Archaea are mostly found in salt water, hot springs, acidic environments, and sulfur containing
environments.