When Were Most of the Existing Lava Plains Formed on the Surface

question 9

Multiple Choice

When were most of the existing lava plains formed on the surface of Mercury?

• A) Never.There is no evidence of lava flows on the surface of Mercury.
• B) When Mercury was first formed,about 4.5 billion years ago
• C) At the end of the era of heavy bombardment,about 3.8 billion years ago
• D) When the crust wrinkled to form the scarps

---

Definitions:

Endocrine Gland

An endocrine gland is a gland that secretes hormones directly into the bloodstream to regulate various bodily functions.

Target Tissue

Specific tissues or cells in an organism that are affected by specific hormones or drugs.

Glucagon

A hormone produced by the pancreas that raises blood glucose levels by promoting the breakdown of glycogen to glucose in the liver.

Gluconeogenesis

A metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.