MCAT BIOLOGY -2025/2026- SET OF QUESTIONS AND
CORRECT ANSWERS ALREADY GRADED A+
GUARANTEED PASS
Differences btwn Prokaryotic and Eukaryotic
Membrane bound organelles - in eukaryotes
Ribosomal subunit weights - diff btwn the two
Presence of nucleus - in eukaryotes
Eukaryotic Cell
Uni- or multi- cellular
Membrane bound organelles
reproduce by mitosis
Nucleus
Control center
Surrounded by nuclear membrane/envelope
Nuclear pores in membrane allow selective exchange btwn nucleus and cytoplasm
Stores DNA (associated with histones)
Single celled
Includes: Archaea and Bacteria
No membrane bound organelles
Circular DNA in Nucleoid Region
Have ribosomes
Nucleoid region
Where Prokaryotic DNA is located
Archaea
1
,Domain of unicellular prokaryotes that have cell walls that do not contain
peptidoglycan
Nucleolus
Found inside the nucleus and produces rRNA
Mitochondria
Powerhouse of the cell
Provides ATP for cell, but also apoptosis by releasing enzymes
Replicate independently (have own genes) via binary fission
DNA is circular, self-replicating, double-stranded
Prokaryotic cell
Bacteria
Prokaryotic
Have cell membrane, cytoplasm, and sometimes flagella/fimbriae
Spherical Bacteria
Cocci
Rod-shaped bacteria
Bacilli
Spiral-shaped bacteria
Spirilli
Mutualistic Symbiote
Both humans and bacteria gain something by having bacteria living in us (in our gut)
pathogen or parasite
No benefit from having in the body, in fact make us sick
Gram positive bacteria
appear purple in response to Gram stain; thick layer of peptidoglycan
No outer-membrane, making susceptible to penicillin
2
,Gram negative Bacteria
appear pink in response to Gram stain; thin layer of peptidoglycan
Also have outer membrane containing lippolysaccharides
Lysosomes
Breakdown waste in cell
Trigger apoptosis as well by releasing enzymes (autolysis) that degrade organelles
Have a single membrane which is good for absorbtion and secreiton
Endosomes
transport, package, and sort cell material traveling to and from the membrane
Rough endoplasmic reticulum (RER)
processes and transports proteins made at attached ribosomes
permit translation of proteins destined for secretion directly into lumen
Smooth Endoplasmic Reticulum (SER)
no ribosomes
Lipid synthesis
detoxification of certain drugs/poisons
Transports proteins
Golgi Apparatus
Modifies and packages proteins
Receives material from ER via vesicles
Peroxisomes
Contain hydrogen peroxide
Breakdown long chain fatty acids via beta-oxidation
Microfilaments
Actin filaments are resistant to compression and fracture
3
, Provide support/protection for sell
Can use ATP to generate force for movement w/ myosin
Microtubules
Spiral strands of protein molecules that form a tubelike structure
Provide pathways for motor proteins (kinesin, dynein)
Make up cilia ("hair" on outside of cell) and flagella (tail)
Flagella
tail-like structure made of microtubules
9+2 structure (9 microtubules on outside and 2 inside) in eukaryotes
HAVE TUBULIN
Centrioles
Cell organelle that aids in cell division in animal cells only
Found in centrosomes near nucleus
aid in microtubule organization in mitotic spindle
Structured as nine triplets of microtubules around hollow center
HAVE TUBULIN
intermediate Filaments
involved in cell-cell adhesion
anchor organelles
Help cytoskeleton integrity
Epithelial tissue
Tissue that covers outside of the body and lines organs and cavities.
Forms basement membrane
Constitute the parachyma (functional part of organ)
Can be involved in the absorption and release of material
4
CORRECT ANSWERS ALREADY GRADED A+
GUARANTEED PASS
Differences btwn Prokaryotic and Eukaryotic
Membrane bound organelles - in eukaryotes
Ribosomal subunit weights - diff btwn the two
Presence of nucleus - in eukaryotes
Eukaryotic Cell
Uni- or multi- cellular
Membrane bound organelles
reproduce by mitosis
Nucleus
Control center
Surrounded by nuclear membrane/envelope
Nuclear pores in membrane allow selective exchange btwn nucleus and cytoplasm
Stores DNA (associated with histones)
Single celled
Includes: Archaea and Bacteria
No membrane bound organelles
Circular DNA in Nucleoid Region
Have ribosomes
Nucleoid region
Where Prokaryotic DNA is located
Archaea
1
,Domain of unicellular prokaryotes that have cell walls that do not contain
peptidoglycan
Nucleolus
Found inside the nucleus and produces rRNA
Mitochondria
Powerhouse of the cell
Provides ATP for cell, but also apoptosis by releasing enzymes
Replicate independently (have own genes) via binary fission
DNA is circular, self-replicating, double-stranded
Prokaryotic cell
Bacteria
Prokaryotic
Have cell membrane, cytoplasm, and sometimes flagella/fimbriae
Spherical Bacteria
Cocci
Rod-shaped bacteria
Bacilli
Spiral-shaped bacteria
Spirilli
Mutualistic Symbiote
Both humans and bacteria gain something by having bacteria living in us (in our gut)
pathogen or parasite
No benefit from having in the body, in fact make us sick
Gram positive bacteria
appear purple in response to Gram stain; thick layer of peptidoglycan
No outer-membrane, making susceptible to penicillin
2
,Gram negative Bacteria
appear pink in response to Gram stain; thin layer of peptidoglycan
Also have outer membrane containing lippolysaccharides
Lysosomes
Breakdown waste in cell
Trigger apoptosis as well by releasing enzymes (autolysis) that degrade organelles
Have a single membrane which is good for absorbtion and secreiton
Endosomes
transport, package, and sort cell material traveling to and from the membrane
Rough endoplasmic reticulum (RER)
processes and transports proteins made at attached ribosomes
permit translation of proteins destined for secretion directly into lumen
Smooth Endoplasmic Reticulum (SER)
no ribosomes
Lipid synthesis
detoxification of certain drugs/poisons
Transports proteins
Golgi Apparatus
Modifies and packages proteins
Receives material from ER via vesicles
Peroxisomes
Contain hydrogen peroxide
Breakdown long chain fatty acids via beta-oxidation
Microfilaments
Actin filaments are resistant to compression and fracture
3
, Provide support/protection for sell
Can use ATP to generate force for movement w/ myosin
Microtubules
Spiral strands of protein molecules that form a tubelike structure
Provide pathways for motor proteins (kinesin, dynein)
Make up cilia ("hair" on outside of cell) and flagella (tail)
Flagella
tail-like structure made of microtubules
9+2 structure (9 microtubules on outside and 2 inside) in eukaryotes
HAVE TUBULIN
Centrioles
Cell organelle that aids in cell division in animal cells only
Found in centrosomes near nucleus
aid in microtubule organization in mitotic spindle
Structured as nine triplets of microtubules around hollow center
HAVE TUBULIN
intermediate Filaments
involved in cell-cell adhesion
anchor organelles
Help cytoskeleton integrity
Epithelial tissue
Tissue that covers outside of the body and lines organs and cavities.
Forms basement membrane
Constitute the parachyma (functional part of organ)
Can be involved in the absorption and release of material
4
