In Which Region of the Hertzsprung-Russell Diagram Does a Newly

question 203

Multiple Choice

In which region of the Hertzsprung-Russell diagram does a newly formed protostar first appear when it begins to shine at visible wavelengths?

• A) bottom right corner; very low luminosity because it is both small and cool
• B) center of the main sequence since all protostars begin their lives at this position and move up or down the diagram, depending on their mass as time passes
• C) right side; relatively large luminosity because of its size but cool temperature
• D) top left corner; at the top of the main sequence, down which it will progress with time

---

Definitions:

Antrum

Cavity of an ovarian follicle filled with fluid containing estrogen.

Prostatic Urethra

The portion of the urethra that runs through the prostate gland, involved in the excretion of urine in males.

Seminal Vesicles

Glands in the male reproductive system that produce and secrete fluid that is a major component of semen.

Peristaltic Contractions

Wave-like muscle contractions that move food through the digestive tract.