So Far, the Known Mechanisms of Replication and MRNA Expression

question 26

Multiple Choice

So far, the known mechanisms of replication and mRNA expression define how many fundamental groups of virus species?

• A) five
• B) six
• C) seven
• D) eight
• E) nine

---

Definitions:

Blastula

An early stage of embryonic development in animals, characterized by a sphere of cells surrounding a central fluid-filled cavity.

Morula

Mass of 12 or more cells resulting from the early cleavage divisions of the zygote.

Placenta

An organ that develops in the uterus during pregnancy, providing oxygen and nutrients to, and removing waste from, the fetus.

Trophoblast

A layer of cells surrounding the blastocyst in early development that provides nutrients to the embryo and develops into part of the placenta.