Correct Answers With Verified Solutions, 100% Correct.
Updated Fall 2024/2025.
Operator
The "switch" is a segment of DNA called an operator usually positioned within the promoter
Operon
the entire stretch of DNA that includes the operator, the promoter, and the genes that they control
Repressor
A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter
site
Corepressor
a molecule that cooperates with a repressor protein to switch an operon off
Inducer
A specific small molecule that inactivates the repressor in an operon.
Cell Differentiation
the process by which a cell becomes specialized for a specific structure or function.
Cytoplasmic Determinants
Maternal substances in egg that influence the course of early development.
Oncogenes
are cancer-causing genes in some types of viruses.
Proto-oncogenes
the corresponding normal cellular genes that are responsible for normal cell growth and division.
Tumor Suppressor Genes
normally help prevent uncontrolled cell growth
Tumor-suppressor proteins
Repair damaged DNA
Control cell adhesion
Act in cell-signaling pathways that inhibit the cell cycle
Virus
, an infectious particle consisting of genes packaged in a protein coat
Capsid
The protein shell that encloses a viral genome. It may be rod-shaped, polyhedral, or more complex in
shape.
Capsids are built from protein subunits called?
Capsomeres
What is the lytic cycle?
a phage replicative cycle that culminates in the death of the host cell
what does the lytic cycle produce?
new phages and lyses (breaks open) the host's cell wall, releasing the progeny viruses.
Virulent Phage
A phage that reproduces only by the lytic cycle.
The lysogenic cycle
replicates the phage genome without destroying the host
Prophage
the viral DNA that is embedded in the host cell's DNA
What happens when the cell divides in the lysogenic cycle?
it copies the phage DNA and passes the copies to daughter cells
Temperate Phages
Phages that use both the lytic and lysogenic cycles
There are two key variables used to classify viruses that infect animals
An RNA or DNA genome
A single-stranded or double-stranded genome
Provirus
The viral DNA that is integrated into the host genome
Vaccines
harmless derivatives of pathogenic microbes that stimulate the immune system to mount defenses
against the harmful pathogen
Plant viruses spread disease in two major modes: