Question

a(n) _________ is a one-celled organism formed by the union of a sperm and an egg.
a. zygote
b. blastocyst
c. embryo
d. fetus

please select the best answer from the choices provided

a
b
c
d

Explanation:

Identify the biological term for a fertilized egg

The question asks for the name of the one-celled organism formed by the union of a sperm and an egg.

Evaluate the given options

• A. zygote: A single cell formed by the fusion of a male gamete (sperm) and a female gamete (egg). This matches the definition.
• B. blastocyst: A multi-cellular structure formed later in the germinal stage, consisting of an inner cell mass and an outer layer.
• C. embryo: The developing organism from about two weeks after fertilization through the eighth week.
• D. fetus: The developing organism from nine weeks after conception until birth.

Select the correct option

Option A is the correct term.

Answer:

• A. zygote (Correct answer)
• B. blastocyst
• C. embryo
• D. fetus