MCB 150 Unit 1 2024/2025 Exam
Questions and Verified Answers |
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Genus - 🧠ANSWER ✔✔species scheme is still used, but 2 kingdoms
(animals and plants) wasn't enough to explain fungi microbes, etc
prokaryote - 🧠ANSWER ✔✔those without a "kernel" / nucleus
eukaryote - 🧠ANSWER ✔✔those with a kernel/nucleus
a typical prokaryotic cell - 🧠ANSWER ✔✔-Nucleoid (usually a single
chromosome): not surrounded by a membrane
-Cytoplasmic membrane: serves role of cytoplasmic membrane and other
internal membranes in eukaryotes, ribosomes in there
-Cell wall (usually but not always present)
-Ex: rod shaped bacteria
eukaryote - 🧠ANSWER ✔✔-Compartmentalization
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,.inside of cell separated into distinct compartments called organelles (note:
this list is representative not exhaustive)
~mitochondrion
~nucleus
~lysosome
~golgi apparatus
~cytoplasmic membrane
~endoplasmic reticulum
• Animal cell
~plants have cell walls and chloroplasts
• ex: human
until 1977, organisms were thought to fall into 2 superkingdoms -
🧠ANSWER ✔✔• Prokaryotes, without a nuclear membrane and membrane
bound organelles
• Eukaryotes, with a nuclear membrane and membrane bound organelles
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,• Physical/structural characteristics are useful for cruse classifications but
to understand true evolutionary relationships ("tree of life", common
ancestor), it's necessary to look at their genomes and biochemical systems
In 1977 Carl Woese and co-workers here at Illinois compared the
sequences in different species of molecules (small subunit ribosomal
RNAs) which are essential component of every cell's machinery for
synthesizing proteins (compare sequences to see how closely related
organisms were)
-Why these ribsomal RNAs? - 🧠ANSWER ✔✔o Evolutionarily ancient
o Found in all organisms
o Same function in all organisms (does same thing in all organisms)
o Highly conserved (sequences very similar; evolved slowly) which is an
indication of how important they are
• Conclusion: "prokaryotes" are actually 2 distinct groups of organisms
~(EU)Bacteria:
~Archea: - 🧠ANSWER ✔✔~EU)BACTERIA: true bacteria like E. Coli; found
everywhere
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STATEMENT. ALL RIGHTS RESERVED
, ~ARCHEA: "ancient" prokaryotes; first discovered in extreme habitats that
resemble early earth
-Extreme heat, pressure, acids, salts, gases, etc
~Conclusion: archeal rRNA sequences than to bacterial rRNA sequences
Revised tree of life was created with 3 domains rather than 2
superkingdoms - 🧠ANSWER ✔✔-Eukarya and archea branched together
then bacteria; all have common ancestor
-Despite physically resembling bacteria (they are both prokaryotes), in most
molecular processes archea are more similar to humans than they are to E
coli
-Bacteria and archea more structurally similar but not genetically!!
-When woese did his work, few genomes available, today 12,274 complete
genomes due to horizontal gene transfer (more common for bacteria and
archea to share genes versus eukarya
No two species are identical structurally and biochemically, but they are all
made up of one or more cells - 🧠ANSWER ✔✔~Life requires a structural
compartment separate from the external environment in which molecules
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 4
STATEMENT. ALL RIGHTS RESERVED
Questions and Verified Answers |
Already Graded A+
Genus - 🧠ANSWER ✔✔species scheme is still used, but 2 kingdoms
(animals and plants) wasn't enough to explain fungi microbes, etc
prokaryote - 🧠ANSWER ✔✔those without a "kernel" / nucleus
eukaryote - 🧠ANSWER ✔✔those with a kernel/nucleus
a typical prokaryotic cell - 🧠ANSWER ✔✔-Nucleoid (usually a single
chromosome): not surrounded by a membrane
-Cytoplasmic membrane: serves role of cytoplasmic membrane and other
internal membranes in eukaryotes, ribosomes in there
-Cell wall (usually but not always present)
-Ex: rod shaped bacteria
eukaryote - 🧠ANSWER ✔✔-Compartmentalization
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 1
STATEMENT. ALL RIGHTS RESERVED
,.inside of cell separated into distinct compartments called organelles (note:
this list is representative not exhaustive)
~mitochondrion
~nucleus
~lysosome
~golgi apparatus
~cytoplasmic membrane
~endoplasmic reticulum
• Animal cell
~plants have cell walls and chloroplasts
• ex: human
until 1977, organisms were thought to fall into 2 superkingdoms -
🧠ANSWER ✔✔• Prokaryotes, without a nuclear membrane and membrane
bound organelles
• Eukaryotes, with a nuclear membrane and membrane bound organelles
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 2
STATEMENT. ALL RIGHTS RESERVED
,• Physical/structural characteristics are useful for cruse classifications but
to understand true evolutionary relationships ("tree of life", common
ancestor), it's necessary to look at their genomes and biochemical systems
In 1977 Carl Woese and co-workers here at Illinois compared the
sequences in different species of molecules (small subunit ribosomal
RNAs) which are essential component of every cell's machinery for
synthesizing proteins (compare sequences to see how closely related
organisms were)
-Why these ribsomal RNAs? - 🧠ANSWER ✔✔o Evolutionarily ancient
o Found in all organisms
o Same function in all organisms (does same thing in all organisms)
o Highly conserved (sequences very similar; evolved slowly) which is an
indication of how important they are
• Conclusion: "prokaryotes" are actually 2 distinct groups of organisms
~(EU)Bacteria:
~Archea: - 🧠ANSWER ✔✔~EU)BACTERIA: true bacteria like E. Coli; found
everywhere
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 3
STATEMENT. ALL RIGHTS RESERVED
, ~ARCHEA: "ancient" prokaryotes; first discovered in extreme habitats that
resemble early earth
-Extreme heat, pressure, acids, salts, gases, etc
~Conclusion: archeal rRNA sequences than to bacterial rRNA sequences
Revised tree of life was created with 3 domains rather than 2
superkingdoms - 🧠ANSWER ✔✔-Eukarya and archea branched together
then bacteria; all have common ancestor
-Despite physically resembling bacteria (they are both prokaryotes), in most
molecular processes archea are more similar to humans than they are to E
coli
-Bacteria and archea more structurally similar but not genetically!!
-When woese did his work, few genomes available, today 12,274 complete
genomes due to horizontal gene transfer (more common for bacteria and
archea to share genes versus eukarya
No two species are identical structurally and biochemically, but they are all
made up of one or more cells - 🧠ANSWER ✔✔~Life requires a structural
compartment separate from the external environment in which molecules
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY 4
STATEMENT. ALL RIGHTS RESERVED
