BIOLOGY 181 STUDY GUIDE 2025/2026 QUESTIONS AND
ANSWERS GRADED A+
✔✔Isotonic: - ✔✔Inside and Outside solutions are isotinic when there is an equal
amount of solutes inside and outside the mebrane
✔✔Channel Proteins: - ✔✔integral protiens
SELECTIVE
-only specific ions/molecules can pass
through
NO energy input
✔✔Carrier Protiens: - ✔✔NO energy input
GLUT-1
✔✔Mitosis: - ✔✔Definition: Somatic cells, Nuclear division,
Outcome: 2 IDENTICAL daughter cells
✔✔Chromosomes: - ✔✔Tightly packed DNA around proteins (histones)
Encodes the cell's genetic information
✔✔Homologous Chromosomes - ✔✔Chromosomes that have the same sequence of
genes and the same structure
✔✔Sister Chromatids: - ✔✔Both chromatid copies in a replicated chromosome
genetically identical material
✔✔Phases of the Cell Cycle and What Happens in Each: - ✔✔Prophase: nuclear
envelope disappears chromosomes condense
Metaphase: chromosomes line up in the middle of the cell
Anaphase: the chromatids are pulled apart
Telophase: nuclear envelope forms again
✔✔Cell Cycle Checkpoints: - ✔✔Major decisions: to continue or stop
-pass G1 if nutrients are available, right size, DNA is NOT physically damaged
-pass G2 if DNA is UN-damaged, chromosomes replicated successfully, activated MPF
is present
-M-Phase chromosomes kinetochores must be attached to the spindle apparatus and
sister chromosomes must have been separated successfully
✔✔What is the mitosis promoting factor?
How do you turn it off/on? - ✔✔MPF: 2 subunits -cyclin, cyclin dependent kinase
Regulatory protein
Induces mitosis
ACTIVATION: late in G2 another enzyme removes 1 phosphate
, DEACTIVATION: during anaphase MPF cyclin is destroyed
✔✔What Is Cancer? - ✔✔Cell Cycle Error
Uncontrolled division -checkpoint failure
✔✔When is a tumor benign/malignant? - ✔✔Benign Tumor: Non-invasive (non-
cancerous) do not spread
Malignant Tumor: Invasive (cancerous) spread to adjacent tissues
✔✔Metastasis: - ✔✔Secondary tumor formation
✔✔DNA: - ✔✔DNA: deoxyribonucleic acid,
double helix,
the most stable molecule,
info storage & passage,
symmetric,
Hydrophilic backbone,
hydrophilic inside
phosphodiester & hydrogen bonds
✔✔RNA: - ✔✔RNA: ribonocleic acid,
Single strand primary structure
sugar-phosphate
nitrogenous bases
comlex
distinct 3-D shape
can make copies of itself
✔✔Difference B/W DNA & RNA?
Which is more stable? - ✔✔DNA is more stable,
RNA is more reactive, Uracil instead of Thymine, more versatile, more functions,
✔✔What is the secondary structure of DNA? - ✔✔Double Helix
# of purines = # of pyrimidines
✔✔What is antiparallel configuration? - ✔✔pairing antiparallel strands 5'-3' and A<=>T
C<=>G
✔✔How are nucleotide bases paired? - ✔✔A<=>T
C<=>G
✔✔Semiconservative Replication: - ✔✔daughter molecules each cnsits of one old and
new strand of DNA
✔✔What Direction is DNA/RNA Synthesized? - ✔✔5'-3'
ANSWERS GRADED A+
✔✔Isotonic: - ✔✔Inside and Outside solutions are isotinic when there is an equal
amount of solutes inside and outside the mebrane
✔✔Channel Proteins: - ✔✔integral protiens
SELECTIVE
-only specific ions/molecules can pass
through
NO energy input
✔✔Carrier Protiens: - ✔✔NO energy input
GLUT-1
✔✔Mitosis: - ✔✔Definition: Somatic cells, Nuclear division,
Outcome: 2 IDENTICAL daughter cells
✔✔Chromosomes: - ✔✔Tightly packed DNA around proteins (histones)
Encodes the cell's genetic information
✔✔Homologous Chromosomes - ✔✔Chromosomes that have the same sequence of
genes and the same structure
✔✔Sister Chromatids: - ✔✔Both chromatid copies in a replicated chromosome
genetically identical material
✔✔Phases of the Cell Cycle and What Happens in Each: - ✔✔Prophase: nuclear
envelope disappears chromosomes condense
Metaphase: chromosomes line up in the middle of the cell
Anaphase: the chromatids are pulled apart
Telophase: nuclear envelope forms again
✔✔Cell Cycle Checkpoints: - ✔✔Major decisions: to continue or stop
-pass G1 if nutrients are available, right size, DNA is NOT physically damaged
-pass G2 if DNA is UN-damaged, chromosomes replicated successfully, activated MPF
is present
-M-Phase chromosomes kinetochores must be attached to the spindle apparatus and
sister chromosomes must have been separated successfully
✔✔What is the mitosis promoting factor?
How do you turn it off/on? - ✔✔MPF: 2 subunits -cyclin, cyclin dependent kinase
Regulatory protein
Induces mitosis
ACTIVATION: late in G2 another enzyme removes 1 phosphate
, DEACTIVATION: during anaphase MPF cyclin is destroyed
✔✔What Is Cancer? - ✔✔Cell Cycle Error
Uncontrolled division -checkpoint failure
✔✔When is a tumor benign/malignant? - ✔✔Benign Tumor: Non-invasive (non-
cancerous) do not spread
Malignant Tumor: Invasive (cancerous) spread to adjacent tissues
✔✔Metastasis: - ✔✔Secondary tumor formation
✔✔DNA: - ✔✔DNA: deoxyribonucleic acid,
double helix,
the most stable molecule,
info storage & passage,
symmetric,
Hydrophilic backbone,
hydrophilic inside
phosphodiester & hydrogen bonds
✔✔RNA: - ✔✔RNA: ribonocleic acid,
Single strand primary structure
sugar-phosphate
nitrogenous bases
comlex
distinct 3-D shape
can make copies of itself
✔✔Difference B/W DNA & RNA?
Which is more stable? - ✔✔DNA is more stable,
RNA is more reactive, Uracil instead of Thymine, more versatile, more functions,
✔✔What is the secondary structure of DNA? - ✔✔Double Helix
# of purines = # of pyrimidines
✔✔What is antiparallel configuration? - ✔✔pairing antiparallel strands 5'-3' and A<=>T
C<=>G
✔✔How are nucleotide bases paired? - ✔✔A<=>T
C<=>G
✔✔Semiconservative Replication: - ✔✔daughter molecules each cnsits of one old and
new strand of DNA
✔✔What Direction is DNA/RNA Synthesized? - ✔✔5'-3'
