BIO 215 EXAM 1 EXAM WITH 100%
DETAILED CORRECT ANSWERS
2025/2026 STUDY SET
Identify characteristics of living things that distinguish them from non-living things. - CORRECT
ANSWERS There are 9 characteristics of living things that distinguish them from non-
living things.
1. Organization
2.Evolution of populations
3. DNA
4. Reproduction
5. Response to environment
6. Metabolism
7. Homeostasis
8. Contain one or more cells.
Give a brief overview of the historical events that contributed to modern cell biology. Recall the
associated names and dates involved in the events discussed in class. - CORRECT ANSWERS
Cells were first observed in 1665 by Robert Hooke. He is credited with coining the term "cell" in
Micrographia. After 1665 there were not many discoveries in cell biology because they were limited by
optical instruments (limited resolving power of microscopes & a lack of detail) and their way of thinking
(more observation, less asking 'why').
1830's there was advancement in optics & in 1831, Robert Brown described the nucleus.
1838 : Schleiden & Schwann put forth the 'Cell Theory'.
Cell Theory - Schwann (1839)
,1) The cell is the unit of structure, physiology, and organization in living things.
2) The cell retains a dual existence as a distinct entity and a building block in the construction of
organisms. 3) Cells form by free-cell formation, similar to the formation of crystals
#3 was wrong and revised by Virchow in 1855. Replaced #3 with "All cells arise from only preexisting
cells".
Summarize the currently accepted cell theory. - CORRECT ANSWERS 1) The cell is a unit
of structure, physiology, and organization in living things
2)The cell retains a dual existence as a distinct entity and a building block in the construction of
organisms.
3)All cells arise from only preexisting cells
Describe the 3 domains of life. - CORRECT ANSWERS Bacteria = Prokaryotes
Archaea = Prokaryotes, many extremophiles
Eukarya = Eukaryotes (Protists, plants, fungi, animals)
Who is credited with redrawing the tree of life into 3 domains? - CORRECT ANSWERS
Carle Woese & George Fox.
Describe the evidence used to reclassify organisms into the 3 domains. Why were rRNA gene sequences
used for to analyze phylogenetic relationships? - CORRECT ANSWERS Carle and Woese
and George Fox redrew phylogenetic relationships based on analysis of rRNA gene sequences.
They used rRNA because
1) all cells require rRNA
2) they change very slowly over time (not much room for variation bc their sequence is so closely related
to its function). Bc of this, any slight changes in sequence reflect an evolutionary "step." rNA can be used
to establish evolutionary relationships between all species.
3) conserved regions enable easy in virto replication
, What information did we learn from the analysis of the rRNA gene sequences pioneered by Woese and
Fox? - CORRECT ANSWERS There were two separate prokaryote groups (Bacteria and
Achaean domains) that were actually very different from each other, although before that they had
always been grouped together bc they are prokaryotes.
Suggested that eukaryotes and archaea are actually more closely related to each other than to bacteria
Allowed a better understanding of how protists should be organized
Revealed how incorrect it was to classify them all together in one kingdom
Some protists are not even closely related at all
What is a protist? Why is it no longer correct to classify all protists together into one phylogenetic
group? - CORRECT ANSWERS A diverse grouping of eukaryotic organisms. Many diverse
lineages of various eukaryotic organisms. Can be unicellular or multicellular. They are so diverse that
they are not closely related enough to group them into one group.
Are viruses considered living organisms? Why or why not? Explain. - CORRECT ANSWERS
No, they do not exhibit multiple characteristics of living things. These characteristics are :
growth/development, response to environment, metabolism, homeostasis, and they do not contain one
or more cells.
Describe the fundamental differences between eukaryotic and prokaryotic cells. - CORRECT ANSWERS
Prokaryotes lack the internal complexity seen in Eukaryotes and are on average much smaller than
eukaryotes. They also lack a nucleus but instead have a "nucleoid region."
Eukaryotic cells have a nucleus and various membrane bound organelles. They are also much larger than
prokaryotes on average.
Describe the structural features shared by all cells. - CORRECT ANSWERS Surrounded by
lipid-based plasma membrane
Metabolic machinery
DNA as hereditary information
Ribosome as protein-synthesizing machinery
DETAILED CORRECT ANSWERS
2025/2026 STUDY SET
Identify characteristics of living things that distinguish them from non-living things. - CORRECT
ANSWERS There are 9 characteristics of living things that distinguish them from non-
living things.
1. Organization
2.Evolution of populations
3. DNA
4. Reproduction
5. Response to environment
6. Metabolism
7. Homeostasis
8. Contain one or more cells.
Give a brief overview of the historical events that contributed to modern cell biology. Recall the
associated names and dates involved in the events discussed in class. - CORRECT ANSWERS
Cells were first observed in 1665 by Robert Hooke. He is credited with coining the term "cell" in
Micrographia. After 1665 there were not many discoveries in cell biology because they were limited by
optical instruments (limited resolving power of microscopes & a lack of detail) and their way of thinking
(more observation, less asking 'why').
1830's there was advancement in optics & in 1831, Robert Brown described the nucleus.
1838 : Schleiden & Schwann put forth the 'Cell Theory'.
Cell Theory - Schwann (1839)
,1) The cell is the unit of structure, physiology, and organization in living things.
2) The cell retains a dual existence as a distinct entity and a building block in the construction of
organisms. 3) Cells form by free-cell formation, similar to the formation of crystals
#3 was wrong and revised by Virchow in 1855. Replaced #3 with "All cells arise from only preexisting
cells".
Summarize the currently accepted cell theory. - CORRECT ANSWERS 1) The cell is a unit
of structure, physiology, and organization in living things
2)The cell retains a dual existence as a distinct entity and a building block in the construction of
organisms.
3)All cells arise from only preexisting cells
Describe the 3 domains of life. - CORRECT ANSWERS Bacteria = Prokaryotes
Archaea = Prokaryotes, many extremophiles
Eukarya = Eukaryotes (Protists, plants, fungi, animals)
Who is credited with redrawing the tree of life into 3 domains? - CORRECT ANSWERS
Carle Woese & George Fox.
Describe the evidence used to reclassify organisms into the 3 domains. Why were rRNA gene sequences
used for to analyze phylogenetic relationships? - CORRECT ANSWERS Carle and Woese
and George Fox redrew phylogenetic relationships based on analysis of rRNA gene sequences.
They used rRNA because
1) all cells require rRNA
2) they change very slowly over time (not much room for variation bc their sequence is so closely related
to its function). Bc of this, any slight changes in sequence reflect an evolutionary "step." rNA can be used
to establish evolutionary relationships between all species.
3) conserved regions enable easy in virto replication
, What information did we learn from the analysis of the rRNA gene sequences pioneered by Woese and
Fox? - CORRECT ANSWERS There were two separate prokaryote groups (Bacteria and
Achaean domains) that were actually very different from each other, although before that they had
always been grouped together bc they are prokaryotes.
Suggested that eukaryotes and archaea are actually more closely related to each other than to bacteria
Allowed a better understanding of how protists should be organized
Revealed how incorrect it was to classify them all together in one kingdom
Some protists are not even closely related at all
What is a protist? Why is it no longer correct to classify all protists together into one phylogenetic
group? - CORRECT ANSWERS A diverse grouping of eukaryotic organisms. Many diverse
lineages of various eukaryotic organisms. Can be unicellular or multicellular. They are so diverse that
they are not closely related enough to group them into one group.
Are viruses considered living organisms? Why or why not? Explain. - CORRECT ANSWERS
No, they do not exhibit multiple characteristics of living things. These characteristics are :
growth/development, response to environment, metabolism, homeostasis, and they do not contain one
or more cells.
Describe the fundamental differences between eukaryotic and prokaryotic cells. - CORRECT ANSWERS
Prokaryotes lack the internal complexity seen in Eukaryotes and are on average much smaller than
eukaryotes. They also lack a nucleus but instead have a "nucleoid region."
Eukaryotic cells have a nucleus and various membrane bound organelles. They are also much larger than
prokaryotes on average.
Describe the structural features shared by all cells. - CORRECT ANSWERS Surrounded by
lipid-based plasma membrane
Metabolic machinery
DNA as hereditary information
Ribosome as protein-synthesizing machinery
