©THESTAR 2024/2025 ALL RIGHTS RESERVED 10:08PM.
BIO 215 EXAM 1 Questions And Answers
2025 Update.
Identify characteristics of living things that distinguish them from non-living things. -
Answer✔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. - Answer✔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
,©THESTAR 2024/2025 ALL RIGHTS RESERVED 10:08PM.
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. - Answer✔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. - Answer✔Bacteria = Prokaryotes
Archaea = Prokaryotes, many extremophiles
Eukarya = Eukaryotes (Protists, plants, fungi, animals)
Who is credited with redrawing the tree of life into 3 domains? - Answer✔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? - Answer✔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? - Answer✔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
2
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 10:08PM.
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? - Answer✔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. - Answer✔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. -
Answer✔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. - Answer✔Surrounded by lipid-based plasma
membrane
Metabolic machinery
DNA as hereditary information
Ribosome as protein-synthesizing machinery
Convert between the different SI/metric prefixes. Recall the prefixes appropriate for describing
cells, subcellular structures and molecules. Convert between standard notation and scientific
notation. - Answer✔Larger subcellular structures/cells : micrometer (1x10^-6 of a meter)
Smaller subcellular structures ; nanometer (nm) (1x10^-9 of a meter) & Angstrom ( 1/10th of a
nm)
Dalton (Da) - unified atomic mass unit ( commonly used to describe size of proteins) = 1.66 x
10^-24 g
Explain why cell size is limited. - Answer✔Cell size is limited by 2 things: resource availability
and surface area to volume ratio. A cell can be limited by resource availability such as limited
space, nutrients, etc. that keep the cell from growing past a certain size. Surface area to volume
ratio is critical to the metabolism of the cell. As cells increase in size, volume increases
proportionally more than SA, which leads to a lower SA to V ratio. This can lead to a
problematic exchange of substances between cells and their environment, which in turn affects
the localized concentrations of molecules which affects the diffusion rates of molecules which
affects the rates of chemical reactions -- slow reaction rates are BAD for living things.
Explain the strategies cells/organisms can use to overcome the limitations imposed by surface
area:volume constraints. - Answer✔Once a cell reaches a certain size, cell division occurs.
3
BIO 215 EXAM 1 Questions And Answers
2025 Update.
Identify characteristics of living things that distinguish them from non-living things. -
Answer✔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. - Answer✔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
,©THESTAR 2024/2025 ALL RIGHTS RESERVED 10:08PM.
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. - Answer✔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. - Answer✔Bacteria = Prokaryotes
Archaea = Prokaryotes, many extremophiles
Eukarya = Eukaryotes (Protists, plants, fungi, animals)
Who is credited with redrawing the tree of life into 3 domains? - Answer✔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? - Answer✔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? - Answer✔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
2
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 10:08PM.
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? - Answer✔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. - Answer✔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. -
Answer✔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. - Answer✔Surrounded by lipid-based plasma
membrane
Metabolic machinery
DNA as hereditary information
Ribosome as protein-synthesizing machinery
Convert between the different SI/metric prefixes. Recall the prefixes appropriate for describing
cells, subcellular structures and molecules. Convert between standard notation and scientific
notation. - Answer✔Larger subcellular structures/cells : micrometer (1x10^-6 of a meter)
Smaller subcellular structures ; nanometer (nm) (1x10^-9 of a meter) & Angstrom ( 1/10th of a
nm)
Dalton (Da) - unified atomic mass unit ( commonly used to describe size of proteins) = 1.66 x
10^-24 g
Explain why cell size is limited. - Answer✔Cell size is limited by 2 things: resource availability
and surface area to volume ratio. A cell can be limited by resource availability such as limited
space, nutrients, etc. that keep the cell from growing past a certain size. Surface area to volume
ratio is critical to the metabolism of the cell. As cells increase in size, volume increases
proportionally more than SA, which leads to a lower SA to V ratio. This can lead to a
problematic exchange of substances between cells and their environment, which in turn affects
the localized concentrations of molecules which affects the diffusion rates of molecules which
affects the rates of chemical reactions -- slow reaction rates are BAD for living things.
Explain the strategies cells/organisms can use to overcome the limitations imposed by surface
area:volume constraints. - Answer✔Once a cell reaches a certain size, cell division occurs.
3
