__________ are called the powerhouses of the cell?

A. –89.2 °C
B. –86.2 °C
C. –83.2 °C
D. –92.2 °C

A. Convex mirror
B. Concave mirror
C. Plane mirror
D. none of these

Mouth mirror used by a dentist is a concave mirror, to get a magnified reflection of the mouth, without inverting the reflection image. A concave mirror is used to form virtual , upright and magnified images, when the object is positioned within focal point and pole of mirror. This property of concave mirror makes it useful for dentists to view magnified images of tooth and cavity etc.

A. Pepsin
B. Trypsin
C. Gastrin
D. Ptyalin

A. Sugars
B. Hormones
C. Vitamins
D. Minerals

Birth control pills contain synthetic forms of estrogen and progesterone. These synthetic hormones help keep the natural levels of estrogen and progesterone in your body constant so that eggs do not mature and the lining of the uterus never develops enough for a fertilized egg to implant.

A. Ingredients dissolve better in chilled water
B. Chilled water enhances the taste
C. Chilled water attracts more carbon dioxide 
D. Chilled water is more hygienic

A. Eyes
B. Throat
C. Lungs
D. Circulatory system