Viruses

Front

Virus Noun

---

[vy-rus]

Back

Virus

---

A nonliving particle of proteins and nucleic acids that reproduces by infecting living cells and using their cellular machinery.

---

Example: This diagram shows the main parts of a virus: the viral genome (genetic material), the capsid (a protective protein coat), and an outer envelope.

Front

Capsid Noun

---

[kap-sid]

Back

Capsid

---

The protective protein coat that surrounds the genetic material, either DNA or RNA, of a virus particle.

---

Example: This diagram shows the structure of a virus, where the capsid is the outer protein shell that protects the genetic material (DNA) inside.

Front

Lytic Infection Noun

---

[lit-ik in-fek-shun]

Back

Lytic Infection

---

A viral reproductive cycle where a virus enters a cell, makes copies, and causes the host cell to burst.

---

Example: This diagram shows the lytic cycle, where a virus attaches to a host cell, replicates inside, and then bursts the cell (lysis) to release many new viruses.

Front

Bacteriophage Noun

---

[bak-teer-ee-oh-fayj]

Back

Bacteriophage

---

A specialized type of virus that specifically targets, infects, and reproduces within bacteria as its host organism.

---

Example: This diagram shows the structure of a bacteriophage, a type of virus that infects bacteria, labeling its main parts like the head, tail, and nucleic acid.

Front

Lysogenic Infection Noun

---

[ly-so-jen-ik in-fek-shun]

Back

Lysogenic Infection

---

A viral cycle where viral DNA integrates into the host's DNA, replicating with it without immediately destroying the cell.

---

Example: This diagram shows a virus inserting its DNA into a host cell, where it integrates and is copied with the cell, illustrating a lysogenic infection.

Front

Prophage Noun

---

[pro-fayj]

Back

Prophage

---

The genetic material of a bacteriophage that has been incorporated into the genome of its bacterial host cell.

---

Example: A virus injects its genetic material (blue) into a bacterium, which then integrates into the bacterium's own DNA (grey) to become a prophage.

Front

Retrovirus Noun

---

[reh-tro-vy-rus]

Back

Retrovirus

---

An RNA virus that replicates by transcribing its RNA into DNA, which is then inserted into the host's genome.

---

Example: This diagram shows the structure of a retrovirus, labeling key parts like the outer envelope, viral RNA, and the special enzyme reverse transcriptase.

Front

Vaccine Noun

---

[vak-seen]

Back

Vaccine

---

A preparation of weakened or inactivated pathogens used to stimulate an immune response and provide immunity against a disease.

---

Example: This image shows vials of a vaccine, which is a substance used to stimulate the body's immune system to produce protection against a specific disease.

Front

Parasite Noun

---

[par-uh-sahyt]

Back

Parasite

---

An organism that lives on or in a host organism, deriving nutrients at the host's expense and causing harm.

---

Example: This diagram shows the life cycle of a tick, a parasite that requires different animal hosts, including humans, to survive and reproduce through its stages.