MCAT Exam ANSWER KEY 2025/ 2026
resolution differentiate close objects
magnification increase size
eyepiece magnification 10x
objective magnification 4x,10x,20x, 100x
-all living things composed of cells
-cell=basic functional unit of life
Cell Theory -cells from other cells only
-cells have DNA (parent-->daughter cells)
total magnification eyepiece x objective
controls light
diaphragm (microscope) image contrast
-commonly used dye
hematoxylin -shows nucleic acids (DNA,RNA)
how does the dye hematoxylin binds to the negative sugar-phosphate backbone
show nucleic acids?
-living organisms
-differences in refractive indices among different subcellular
phase contrast microscope structures
-atomic level
-samples must be sliced thinly and impregnated with heavy metals
electron microscope for contrast
prokaryotes before nuclei (no nuclei)
eukaryotes after nuclei
types of prokaryotes bacteria and blue-green algae
-unicellular
-no nucleus or membrane bound organelles
prokaryote characteristics -cell wall in all
-ability to carry other pieces of DNA
What type of genetic material is -single circle molecule of DNA
-within nucleoid region
present within prokaryotes?
-circular DNA
-small
plasmids -few genes
-replicate independently
cocci spherical bacteria
bacilli rod-shaped bacteria
how do antibacterials work? tend to attack bacterial specific structures
,MCAT Exam ANSWER KEY 2025/ 2026
-protists, fungi, plants, and animals
-cell walls in fungi and plants
Eukaryote characteristics -nucleus
-unicellular or multicellular
-actin filaments
-intermediate filaments
cytoskeleton proteins -microtubules
Smallest cytoskeleton proteins actin filaments
largest cytoskeleton proteins microtubules
-hydrophobic nonpolar tail
-hydrophilic polar head
phospholipid bilayer -cholesterol molecules
purpose of cholesterol in regulate fluidity
phospholipid bilayer
-control entry/exit
transport proteins -polar molecules and ions allowed through
-CAMs
-allow cells to recognize each other
cell adhesion molecule purpose -proper cell differentiation and development
-double membrane
nucleus membrane -nuclear membrane/envelope
purpose of nucleolus ribosomal RNA synthesized (rRNA)
-protein production
Ribosomes -free and bound types
Endoplasmic Reticulum -production and sorting of materials from cell
smooth ER purpose lipid synthesis and detox drugs/poisons
rough ER purpose protein production
Golgi structure membrane bound sacs
-receives from smooth ER
golgi purpose -repackages to cell surface via secretory vescicles
-'garbage dumps'
-receives from endosomes
-uses hydrolytic enzymes at lowered pH
-break down materials
lysosomes -remove old cell components and replace
-can cause autolysis
autolysis cell suicide
,MCAT Exam ANSWER KEY 2025/ 2026
powerhouse
-2 layers
mitochondria -semi-autonomous
-inherited only from the mother
outer-walls
2 layers of mitochondria inner-electron transport chain
what is the purpose of cristae on increase surface area
mitochondria?
own genes
semi-autonomous -replicate independently
-peroxisomes
types of microbodies -glyoxysomes
-create hydrogen peroxide
-break down fats
peroxisomes -catalyze detox
-germinating plants
glyoxysomes -convert fats to sugars
-in plants and algae
-powerhouse
-contain chlorophyll
chloroplasts -generation of energy
-own DNA
plant cell wall composition cellulose
fungi cell wall composition chitin
animal cell wall composition no cell wall!!
-specialized microtubules
-spindle formation
centrioles -no membrane
-in animals not in plants
-rods of actin
-muscular contraction with interaction with myosin
microfilaments -movement of materials within cell membrane
-hollow
-polymers of tubulin
-throughout cell
microtubules -transport and structural support
-structural basis for cilia and flagella
intermediate fillaments integrity of cytoskeleton
-water movement
osmosis -low solute to high solute
, MCAT Exam ANSWER KEY 2025/ 2026
-solute inside of cell greater than surrounding
hypotonic solution -causes cell to swell
hypertonic solution -solute inside of cell less than surrounding
-large
What types of materials are -polar
impermeable to membrane? -charged
pinocytosis endocytosis of fluids and small particles
phagocytosis ingestion of large molecules
-small
Molecules through simple -nonpolar
diffusion -e.g. O2, CO2
-large
Molecules through facilitated -nonpolar
diffusion -e.g. glucose
-polar
Molecules through active -ions
transport -e.g. Na+,Cl-,K+
-cover body
-line cavities
Epithelial tissue -protection, absorption, secretion, and sensation
-supports body
connective tissue -bone, cartilage, tendons, ligaments, adipose tissue, blood
-cell signaling
nervous tissue -coordinated control
muscle tissue -skeletal, smooth, cardiac
-acellular
-nucleic acids with protein coat
viruses characteristics -has capsid
-
-circular or linear
-single or double stranded
genetic info of viruses -DNA or RNA
obligate intracellular parasites express and replicate within a cell
virions new copies of DNA
capsid protein coat
-viruses that target bacteria
Bacteriophages -inject genetics only not entire body
endothermic requires energy (heat)
resolution differentiate close objects
magnification increase size
eyepiece magnification 10x
objective magnification 4x,10x,20x, 100x
-all living things composed of cells
-cell=basic functional unit of life
Cell Theory -cells from other cells only
-cells have DNA (parent-->daughter cells)
total magnification eyepiece x objective
controls light
diaphragm (microscope) image contrast
-commonly used dye
hematoxylin -shows nucleic acids (DNA,RNA)
how does the dye hematoxylin binds to the negative sugar-phosphate backbone
show nucleic acids?
-living organisms
-differences in refractive indices among different subcellular
phase contrast microscope structures
-atomic level
-samples must be sliced thinly and impregnated with heavy metals
electron microscope for contrast
prokaryotes before nuclei (no nuclei)
eukaryotes after nuclei
types of prokaryotes bacteria and blue-green algae
-unicellular
-no nucleus or membrane bound organelles
prokaryote characteristics -cell wall in all
-ability to carry other pieces of DNA
What type of genetic material is -single circle molecule of DNA
-within nucleoid region
present within prokaryotes?
-circular DNA
-small
plasmids -few genes
-replicate independently
cocci spherical bacteria
bacilli rod-shaped bacteria
how do antibacterials work? tend to attack bacterial specific structures
,MCAT Exam ANSWER KEY 2025/ 2026
-protists, fungi, plants, and animals
-cell walls in fungi and plants
Eukaryote characteristics -nucleus
-unicellular or multicellular
-actin filaments
-intermediate filaments
cytoskeleton proteins -microtubules
Smallest cytoskeleton proteins actin filaments
largest cytoskeleton proteins microtubules
-hydrophobic nonpolar tail
-hydrophilic polar head
phospholipid bilayer -cholesterol molecules
purpose of cholesterol in regulate fluidity
phospholipid bilayer
-control entry/exit
transport proteins -polar molecules and ions allowed through
-CAMs
-allow cells to recognize each other
cell adhesion molecule purpose -proper cell differentiation and development
-double membrane
nucleus membrane -nuclear membrane/envelope
purpose of nucleolus ribosomal RNA synthesized (rRNA)
-protein production
Ribosomes -free and bound types
Endoplasmic Reticulum -production and sorting of materials from cell
smooth ER purpose lipid synthesis and detox drugs/poisons
rough ER purpose protein production
Golgi structure membrane bound sacs
-receives from smooth ER
golgi purpose -repackages to cell surface via secretory vescicles
-'garbage dumps'
-receives from endosomes
-uses hydrolytic enzymes at lowered pH
-break down materials
lysosomes -remove old cell components and replace
-can cause autolysis
autolysis cell suicide
,MCAT Exam ANSWER KEY 2025/ 2026
powerhouse
-2 layers
mitochondria -semi-autonomous
-inherited only from the mother
outer-walls
2 layers of mitochondria inner-electron transport chain
what is the purpose of cristae on increase surface area
mitochondria?
own genes
semi-autonomous -replicate independently
-peroxisomes
types of microbodies -glyoxysomes
-create hydrogen peroxide
-break down fats
peroxisomes -catalyze detox
-germinating plants
glyoxysomes -convert fats to sugars
-in plants and algae
-powerhouse
-contain chlorophyll
chloroplasts -generation of energy
-own DNA
plant cell wall composition cellulose
fungi cell wall composition chitin
animal cell wall composition no cell wall!!
-specialized microtubules
-spindle formation
centrioles -no membrane
-in animals not in plants
-rods of actin
-muscular contraction with interaction with myosin
microfilaments -movement of materials within cell membrane
-hollow
-polymers of tubulin
-throughout cell
microtubules -transport and structural support
-structural basis for cilia and flagella
intermediate fillaments integrity of cytoskeleton
-water movement
osmosis -low solute to high solute
, MCAT Exam ANSWER KEY 2025/ 2026
-solute inside of cell greater than surrounding
hypotonic solution -causes cell to swell
hypertonic solution -solute inside of cell less than surrounding
-large
What types of materials are -polar
impermeable to membrane? -charged
pinocytosis endocytosis of fluids and small particles
phagocytosis ingestion of large molecules
-small
Molecules through simple -nonpolar
diffusion -e.g. O2, CO2
-large
Molecules through facilitated -nonpolar
diffusion -e.g. glucose
-polar
Molecules through active -ions
transport -e.g. Na+,Cl-,K+
-cover body
-line cavities
Epithelial tissue -protection, absorption, secretion, and sensation
-supports body
connective tissue -bone, cartilage, tendons, ligaments, adipose tissue, blood
-cell signaling
nervous tissue -coordinated control
muscle tissue -skeletal, smooth, cardiac
-acellular
-nucleic acids with protein coat
viruses characteristics -has capsid
-
-circular or linear
-single or double stranded
genetic info of viruses -DNA or RNA
obligate intracellular parasites express and replicate within a cell
virions new copies of DNA
capsid protein coat
-viruses that target bacteria
Bacteriophages -inject genetics only not entire body
endothermic requires energy (heat)
