What is the term for the developing human from about nine weeks after conception to birth, capable of hearing sounds and reacting to light?

What is the term for the developing human from about nine weeks after conception to birth, capable of hearing sounds and reacting to light?

• A. Fetus
• B. Embryo
• C. Zygote
• D. Gastrula

Answer: (A)

The key idea is the developmental stage that starts when most major structures are formed and the fetus begins to mature and respond to stimuli. From about the ninth week after conception until birth, the developing human is called a fetus. At this point, the nervous system and sense organs are sufficiently developed to allow responses to external stimuli, such as sounds and light, which fits the description given. Zygote refers to the fertilized egg from conception until implantation, a very early stage. Embryo describes the stage from fertilization up to roughly eight weeks, before major organ development is complete. Gastrula is an even earlier embryonic stage during gastrulation.

The key idea is the developmental stage that starts when most major structures are formed and the fetus begins to mature and respond to stimuli. From about the ninth week after conception until birth, the developing human is called a fetus. At this point, the nervous system and sense organs are sufficiently developed to allow responses to external stimuli, such as sounds and light, which fits the description given.

Zygote refers to the fertilized egg from conception until implantation, a very early stage. Embryo describes the stage from fertilization up to roughly eight weeks, before major organ development is complete. Gastrula is an even earlier embryonic stage during gastrulation.