110 Questions
Which type of virus has a DNA genome and uses the host cell's nucleus and machinery for replication and transcription?
DNA virus
What is the function of reverse transcriptase in retroviruses?
Synthesis of cDNA from RNA
What is the characteristic of the lysogenic cycle?
Virus is integrated into host genome
What is the term for the process of RNA-mediated replication and transcription in RNA viruses?
RdRp
Which type of virus has a single-stranded RNA genome and uses its own machinery for replication and transcription?
RNA virus
What is the term for the process where a virus replicates fast and lyses the host cell?
Lytic
What is the characteristic of viroids?
Is a small circular ssRNA
What is the result of protein misfolding in prions?
Decrease in solubility
What is a characteristic of ssRNA(+) viruses?
Uses RdRp for replication
What is a characteristic of bacteriophages?
Has a lytic and lysogenic life cycle
Which type of virus uses RNA genome, replicates with RdRp inside capsid, and does not involve transcription?
ssRNA(+) viruses
What is the characteristic of Retroviruses in terms of genetic material and enzyme?
Contain two copies of dsRNA and reverse transcriptase
Which type of virus has a genome identical to the host's DNA and utilizes the host cell's replication and transcription machinery?
dsDNA viruses
In terms of replication and transcription mechanisms, which group of viruses involves RdRp performing both functions?
ssRNA(–) viruses
What is the primary effect of prion proteins undergoing misfolding?
Conformational change leading to decreased solubility
Which type of virus carries a circular single-stranded RNA without a protective capsid and primarily affects plants except for Hepatitis D in humans?
Viroids
What is the shape of a bacterium classified as cocci?
Spheres
What is the primary function of the flagella in prokaryotic cells?
Chemotaxis
Which type of prokaryotic cell can tolerate oxygen but prefers to grow in its absence?
Aerotolerant anaerobe
What is the characteristic unique to obligate anaerobes?
Dies in the presence of oxygen
What is the process by which bacteria can acquire new genetic information from their environment?
Transformation
What is a characteristic of Archaea that is similar to Eukarya?
Presence of histones
What is the phase of bacterial growth where the cell population remains constant?
Stationary phase
What is the primary function of the Golgi apparatus in eukaryotic cells?
Modification of materials received from the endoplasmic reticulum
Which organelle is responsible for protein translation and secretion in eukaryotic cells?
Rough endoplasmic reticulum
Cilia and flagella found in eukaryotic cells share a similar internal structure. What is this structure?
9+2
What is the primary function of mitochondria in eukaryotic cells?
Cellular respiration and ATP production
What is the primary role of peroxisomes in eukaryotic cells?
Processing and modification of lipids and carbohydrates
Which type of tissue forms the linings of body cavities and organs?
Epithelial tissue
Which type of virus has a single-stranded RNA genome and relies on RdRp for replication but not transcription?
ssRNA(–) virus
During infection, which virus integrates its genetic material into the host genome in the lysogenic cycle?
dsDNA virus
What is the primary characteristic of retroviruses that differentiates them from other viruses?
Reverse transcriptase enzyme
For which type of virus do RdRp enzymes perform both replication and transcription processes as part of their life cycle?
ssRNA(–) viruses
Which class of viruses utilizes the host cell's nucleus and machinery for replication?
dsDNA viruses
What is the primary function of reverse transcriptase enzyme in retroviruses?
Synthesis of cDNA from RNA
Which type of virus carries a circular single-stranded RNA and does not have a protective capsid, affecting primarily plants?
Viroid
What is the primary mechanism by which bacteria can acquire new genetic information from other bacteria?
Conjugation
Which type of prokaryotic cell requires oxygen for survival and cannot live without it?
Obligate aerobes
What is the primary function of the cell wall in prokaryotic cells?
Regulation of osmotic pressure
Which of the following is a type of bacteria with a spiral shape?
Spirilla
Which of the following processes results in the transfer of DNA from the environment to the bacterial cell?
Transformation
Which of the following is the phase of bacterial growth where the cell population remains constant?
Stationary phase
What is the main function of the nucleolus in eukaryotic cells?
Synthesis of rRNA
Which organelle is responsible for lipid synthesis and detoxification in eukaryotic cells?
Smooth endoplasmic reticulum
Which type of prokaryotic cell can switch between using oxygen and using anaerobic respiration?
Facultative anaerobes
Which organelle is responsible for the modification of materials from the ER in eukaryotic cells?
Golgi apparatus
Which type of epithelial tissue forms the linings of body cavities and organs?
Epithelial tissue
What is the primary role of cilia and flagella in eukaryotic cells?
Cell surface movement
Which organelle assists in the pentose phosphate pathway in eukaryotic cells?
Peroxisomes
What is the primary function of RdRp enzyme in RNA viruses?
To replicate RNA genome
Which type of virus has a single-stranded RNA genome and uses its own machinery for replication and transcription?
RNA virus
What is the characteristic of Prions?
Misfolded proteins
What is the primary function of Reverse Transcriptase enzyme in Retroviruses?
To synthesize DNA from RNA
Which type of virus has a double-stranded RNA genome?
dsRNA virus
What is the characteristic of the Lytic cycle?
Virus replicates fast and lyses host cell
What is the term for the structure in prokaryotic cells that contains genetic material?
Nucleoid
What is the term for the process by which bacteria can acquire new genetic information from other bacteria through direct cell-to-cell contact?
Conjugation
What is the characteristic that distinguishes Archaea from Bacteria?
Presence of histones
What is the term for the process by which viruses infect bacterial cells and transfer genetic material?
Transduction
What is the shape of bacteria classified as spirilla?
Spiral
What is the term for the period of bacterial growth where the cell population grows rapidly?
Log phase
What is the primary function of the mitochondria in eukaryotic cells?
Energy production
What is the term for the process of cell death where the cell breaks down and releases hydrolytic enzymes?
Autolysis
What is the function of the rough endoplasmic reticulum in eukaryotic cells?
Protein synthesis
What is the term for the structures composed of tubulin that are involved in motor protein pathways and centrioles in eukaryotic cells?
Microtubules
What is the function of the nucleolus in eukaryotic cells?
rRNA synthesis
What is the name of the enzyme involved in the production of H2O2 in peroxisomes?
Catalase
What is the function of the Golgi apparatus in eukaryotic cells?
Protein modification
What is the primary function of microfilaments (actin rods) in cells?
Muscle contraction and cleavage furrow
What is the primary function of intermediate filaments (keratin, desmin, vimentin, lamins) in cells?
Protection, cell-cell adhesion, and maintain cytoskeleton
What is the process of cell death characterized by release of cytochrome C from the electron transport chain?
Apoptosis
What is the process of cell death where the cell breaks down and releases hydrolytic enzymes?
Autolysis
What is the function of intermediate filaments (keratin, desmin, vimentin, lamins) in maintaining cell structure?
All of the above
Which structural component of the cytoskeleton is primarily responsible for maintenance of overall cell shape?
Intermediate Filaments
What type of anaerobe can only grow and reproduce in the absence of oxygen?
Obligate anaerobe
Which type of viruses contains a single strand of positive-sense RNA as their genetic material?
ssRNA(+) viruses
Which shape of bacteria refers to those that are rod-shaped?
Bacilli
Which type of epithelium is also known as 'pavement epithelium' due to its flat, scale-like cells?
Squamous
Which type of bacteria has a thick layer of peptidoglycan in its cell wall?
Gram-positive
What type of bacteria can survive in the presence of oxygen, but cannot use it for metabolism?
Aerotolerant anaerobe
Which genetic element can integrate itself into the host bacterium's genome?
Episome
What is a vesicle that pinches off from the membrane during endocytosis?
Endosome
What type of viral genome uses RdRp enzyme for replication and transcription?
Single-stranded RNA
Which organelle is responsible for generating energy in eukaryotic cells?
Mitochondria
Which prokaryotic cell type cannot survive in the presence of oxygen?
Obligate anaerobe
Which organelle is responsible for protein translation and secretion in eukaryotic cells?
Rough endoplasmic reticulum
What is the main function of flagella in a cell?
To generate force for cell movement
What is the role of histone proteins in eukaryotic cells?
To wind DNA into a more compact form
What is the primary function of peroxisomes?
To contain and break down hydrogen peroxide
What is the region of the cell where centrioles are found?
Centrosome
What is the function of cilia in a cell?
To move materials along the cell's surface
What is the characteristic of facultative anaerobes?
They can switch between anaerobic and aerobic metabolism
What is a chromosome?
A DNA molecule with some or all of the genetic information of a cell
What is a centriole composed of?
Microtubules
What is the shape of a bacterium classified as spirilli?
Long thin spirals
What does it mean for an organelle to be semiautonomous?
It can perform a couple of functions on its own independently from the cell
What is the primary characteristic of columnar epithelium?
Long, thin, column shaped cells
What does it mean to be a eukaryotic cell?
To have nuclei and membrane bound organelles
What is the primary characteristic of cuboidal epithelium?
Cube shaped cells
What does it mean to be a female bacterium?
To accept conjugation bridge and genetic info from the donor male
What is the primary characteristic of squamous epithelial cells?
Flat, scale-like cells
What is unique about the ribosomes found in mitochondria?
They are similar in size to prokaryotic ribosomes
What is the primary function of connective tissue in the body?
To provide a framework for epithelial cells to carry out their function
What is the function of lysosomes?
To digest both foreign material and damaged organelles
What is the function of the mitochondrial outer membrane?
To serve as a selective barrier between the cytosol and the mitochondrial inner environment
What is the function of the hook?
To connect the filament and the basal body to facilitate motion
What is the function of the nucleolus?
To synthesize ribosomal RNA
What is the order of taxonomy from most general to most specific?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What is the mitochondrial matrix?
The space inside the mitochondrion's inner membrane
What is the function of the nucleus?
To act as the control center of the cell
Study Notes
Cell Theory
- All organisms are made up of cells
- Cells are the basic functional unit of life
- Cells come from pre-existing cells
- Cells carry genetic information (DNA)
Eukaryotic Cells
Nucleus
- Double-layered envelope containing DNA
- Nucleolus synthesizes rRNA
Mitochondria
- Outer membrane, intermembrane space, inner membrane, matrix
- Proton-motive force: H+ pumped from matrix to intermembrane space
- Apoptosis via release of cytochrome C from ETC
Endoplasmic Reticulum
- Rough ER: studded ribosomes, translates secreted proteins
- Smooth ER: lipid synthesis, detoxification, protein transport
Golgi Apparatus
- Modifies materials from ER
Peroxisomes
- H2O2 production to break down VLCFA
- Assists in phospholipid synthesis and pentose phosphate pathway
Cytoskeleton
- Microfilaments (actin rods): protection, muscle contraction, cleavage furrow
- Microtubules (tubulin tubes): motor protein pathway, centrioles, cilia (cell surface movement), flagella (overall cell movement)
- Intermediate filaments (keratin, desmin, vimentin, lamins): cell-cell adhesion, maintain cytoskeleton, cell rigidity, anchor organelles
Types of Tissues
Epithelial
- Lines body/cavities and forms parenchyma
- Squamous, cuboidal, columnar
- Simple, pseudostratified, stratified
Connective
- Supports body and forms framework for epithelia, forms stroma
- Secretes collagen/elastin to form ECM
- Cardiac (more info in Cardiovascular System)
- Nervous (more info in Nervous System)
Prokaryotic Cells - Bacteria
Structure
- Cocci (spheres), bacilli (rods), spirilla (spiral)
- Single circular chromosome in nucleoid
- Envelope (cell wall and plasma membrane)
- Gram staining
- Flagella (filament, hook, basal body → chemotaxis)
O2 Requirement
- Obligate aerobes (no oxygen → death)
- Facultative anaerobes (switch between O2 or no O2)
- Microaerophiles (tolerates only low amounts of oxygen)
- Aerotolerant anaerobes (can tolerate oxygen)
- Obligate anaerobes (oxygen → death)
Recombination
- Transformation (acquired from environment)
- Conjugation (transferred between bacteria)
- Transduction (acquired by viruses)
Growth Stages
- Lag phase
- Log phase
- Stationary phase
- Death phase
Archaea (compared to bacteria)
Similarities
- Singular circular chromosome
- Similar structure (no LPS/PDG)
- Binary fission
Differences
- Start translation with methionine, histones, and similar RNA pol to eukaryotes
Viruses
Virions (nucleocapsid)
- DNA viruses (DNA genome, nucleus, host machinery)
- dsDNA (identical to host DNA)
- Host replication and transcription
- ssDNA
- Host replication and transcription
- RNA viruses (RNA genome, cytoplasm, own machinery)
- dsRNA (occurs in eukaryotes if targeted)
- Replication w/ RdRp inside capsid, no transcription
- ssRNA(+)
- Replication w/ RdRp, no transcription
- ssRNA(-)
- RdRp performs replication and transcription
Retroviruses
- Two copies of ssRNA, has reverse transcriptase → cDNA from RNA
Life Cycle (bacteriophages only)
- Lytic (virulent, virus replicates fast and lyses host cell)
- Lysogenic (temperate, virus integrated into host genome)
Other
-
Viroids (small circular ssRNA w/ no capsid, affects plants except for Hep.D in humans)
-
Prions (misfolded proteins, α helices to β-pleated sheets → solubility ↓, degradation ↓)### Bacterial Shapes
-
Cocci bacteria are shaped like small spheres.
-
Spirilli bacteria are shaped like long thin spirals.
Mitochondria
- Mitochondria are semiautonomous, meaning they can perform some functions independently of the cell.
- Mitochondria contain their own genes in the form of circular DNA strands.
- Mitochondria have their own ribosomes, similar in size to prokaryotic ribosomes.
- Mitochondria can divide independently of the cell as a whole through binary fission.
Epithelial Cells
- Columnar Epithelium is composed of long, thin, column-shaped cells.
- Cuboidal Epithelium is composed of cube-shaped cells.
- Squamous Epithelium is composed of flat, scale-like epithelial cells.
Cell Types
- Eukaryotic cells are cells that have nuclei and membrane-bound organelles.
Bacterial Sex
- A female bacterium (F-) does not have a sex factor plasmid.
- Female bacteria accept the conjugation bridge and genetic info from the donor male.
- A male bacterium has a sex factor plasmid, which is used for conjugation.
Test your knowledge on cell theory, eukaryotic cells, and cellular structures as covered in the MCAT Biology Section 1. Topics include the basic principles of cell theory, the structure and functions of eukaryotic cells, and key cellular organelles.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
