Question

question 8 of 10
all multicellular organisms begin as a single cell. within four or five days, that first cell multiplies into a ball - like structure of about 100 cells. what is this structure called?
a. blood
b. placenta
c. blastocyst
d. heart

Explanation:

In human development, a single - cell zygote multiplies and forms a blastocyst, a ball - like structure with about 100 cells within 4 - 5 days. Blood is a body fluid, the placenta is an organ for nutrient exchange later in pregnancy, and the heart is an organ that develops much later.

Answer:

C. Blastocyst