MCAT Biology Practice
Questions with Verified Latest
2025-2026 Correct Answers
GRADED A+
Cell Theory
- ANS - Four Tenets:
1. All living things are composed of cells
2. The cell is the basic functional unit of life
3. Cells arise only from preexisting cells
4. Cells carry genetic information in the form of DNA
Eukaryotic Cells
- ANS - Contain a true nucleus enclosed in a membrane.
Prokaryotic Cells
- ANS - Do not contain a nucleus.
Organelles
- ANS - Suspended in semifluid cytosol. In eukaryotic cells they
,are membrane bound, allowing for compartmentalization of
functions. The membranes are made of a phospholipid bilayer,
surfaces are hydrophilic, they interact with the environment.
Cytosol
- ANS - Allows for diffusion of molecules throughout the cell.
Nucleus
- ANS - Genetic material is encoded in DNA, organized in
chromosomes. This DNA provides all the genetic material
needed for replication of the cell. It is surrounded by the
nuclear membrane or envelope, which forms a double
membrane. Nuclear pores allow for selective exchange of
material between cytoplasm and the nucleus.
Genetic Material of the Nucleus
- ANS - DNA contains coding regions called genes. Linear DNA
is wound around organizing proteins known as histones, and
further wound into chromosomes.
Nuclear Membrane
- ANS - Contains nuclear pores that allow for selective 2-way
exchange of material between the cytoplasm and the nucleolus
,Nucleolus
- ANS - -Subsection of the nucleus
-Where ribosomal RNA is synthesized
-The darker spot that is 25% of the nucleus
Mitochondria
- ANS - Power plant of the cell. Two layers, inner and outer
membrane. The outer membrane is a barrier between the
cytosol and the inner environment of the mitochondria. The
inner membrane, made up of infoldings called cristae, contains
the molecules and enzymes necessary for the electron
transport chain. The intermembrane space separates them,
creating a matrix between them.
The pumping of protons from the matrix to the intermembrane
space creates a proton-motive force that generates ATP via
protons flowing through and turning ATP synthase (oxidative
phosphorylation). The mitochondria is semiautonomous,
meaning they replicate independently of the the nucleus via
binary fission.
They can kill the cell via release of enzymes that aid in
apoptosis.
, Lysosomes
- ANS - Membrane-bound structures containing hydrolytic
enzymes that are capable of breaking down many different
substrates, including those ingested by endocytosis and
cellular waste products.
The enzymes are sequestered to protect the cell, releasing
these enzymes causes autolysis, resulting in apoptosis...in this
case, the released enzymes directly lead to cell degradation.
Rough Endoplasmic Reticulum (RER)
- ANS - Interconnected membranes that are actually contiguous
with the nuclear envelope. It is folding into complex structures
with a central lumen. The Rough ER is studded with ribosomes
that permit translation of proteins destined for secretion into
the lumen.
Golgi Apparatus
- ANS - Stacked membrane-bound sacs that are transferred
from the ER via vesicles. The Golgi modifies the products via
addition of various groups. It modifies cellular products
thought the introduction of signal sequences, which help
direct the delivery of product to a specific cellular location.
Can also send to lysosomes for degredation
Questions with Verified Latest
2025-2026 Correct Answers
GRADED A+
Cell Theory
- ANS - Four Tenets:
1. All living things are composed of cells
2. The cell is the basic functional unit of life
3. Cells arise only from preexisting cells
4. Cells carry genetic information in the form of DNA
Eukaryotic Cells
- ANS - Contain a true nucleus enclosed in a membrane.
Prokaryotic Cells
- ANS - Do not contain a nucleus.
Organelles
- ANS - Suspended in semifluid cytosol. In eukaryotic cells they
,are membrane bound, allowing for compartmentalization of
functions. The membranes are made of a phospholipid bilayer,
surfaces are hydrophilic, they interact with the environment.
Cytosol
- ANS - Allows for diffusion of molecules throughout the cell.
Nucleus
- ANS - Genetic material is encoded in DNA, organized in
chromosomes. This DNA provides all the genetic material
needed for replication of the cell. It is surrounded by the
nuclear membrane or envelope, which forms a double
membrane. Nuclear pores allow for selective exchange of
material between cytoplasm and the nucleus.
Genetic Material of the Nucleus
- ANS - DNA contains coding regions called genes. Linear DNA
is wound around organizing proteins known as histones, and
further wound into chromosomes.
Nuclear Membrane
- ANS - Contains nuclear pores that allow for selective 2-way
exchange of material between the cytoplasm and the nucleolus
,Nucleolus
- ANS - -Subsection of the nucleus
-Where ribosomal RNA is synthesized
-The darker spot that is 25% of the nucleus
Mitochondria
- ANS - Power plant of the cell. Two layers, inner and outer
membrane. The outer membrane is a barrier between the
cytosol and the inner environment of the mitochondria. The
inner membrane, made up of infoldings called cristae, contains
the molecules and enzymes necessary for the electron
transport chain. The intermembrane space separates them,
creating a matrix between them.
The pumping of protons from the matrix to the intermembrane
space creates a proton-motive force that generates ATP via
protons flowing through and turning ATP synthase (oxidative
phosphorylation). The mitochondria is semiautonomous,
meaning they replicate independently of the the nucleus via
binary fission.
They can kill the cell via release of enzymes that aid in
apoptosis.
, Lysosomes
- ANS - Membrane-bound structures containing hydrolytic
enzymes that are capable of breaking down many different
substrates, including those ingested by endocytosis and
cellular waste products.
The enzymes are sequestered to protect the cell, releasing
these enzymes causes autolysis, resulting in apoptosis...in this
case, the released enzymes directly lead to cell degradation.
Rough Endoplasmic Reticulum (RER)
- ANS - Interconnected membranes that are actually contiguous
with the nuclear envelope. It is folding into complex structures
with a central lumen. The Rough ER is studded with ribosomes
that permit translation of proteins destined for secretion into
the lumen.
Golgi Apparatus
- ANS - Stacked membrane-bound sacs that are transferred
from the ER via vesicles. The Golgi modifies the products via
addition of various groups. It modifies cellular products
thought the introduction of signal sequences, which help
direct the delivery of product to a specific cellular location.
Can also send to lysosomes for degredation
