Radioactive Isotopes Are Biological Tools That Are Often Used To

question 56

Multiple Choice

Radioactive isotopes are biological tools that are often used to:

• A)measure the size of fossils.
• B)detect brain tumors.
• C)build up a store of calcium in a cell.
• D)increase the pH of blood.

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Definitions:

Germinal Stage

The initial phase of prenatal development that spans from conception to the implantation of the embryo in the uterine wall.

Blastocyst

An early stage in human embryonic development that consists of a sphere of cells surrounding a fluid-filled cavity and the cluster of cells from which the embryo develops.

Embryonic Stage

The period in prenatal development from the second to the eighth week after fertilization, during which major organs and structures of the organism begin to develop.

Fetal Stage

The developmental period in pregnancy from the ninth week after fertilization until birth, when significant growth and maturation of the fetus occur.