Which type of bond connects the hydrogen and oxygen atoms within a water molecule?

Choose the correct option ($T$-true,$F$-false).
$(I)$ Melting point of oil is lower.
$(II)$ All amino acids are acidic.
$(III)$ Lipid is water soluble.
$(IV)$ Enzyme shows its highest activity at a particular temperature.
$I - II - III - IV$

Which of the following is a correct sequence for the appearance of compounds in a cell?

Molecules are always moving. Some molecules move faster than others; . . . . . . is a measure of their average velocity of movement.

Which vitamin is destroyed by ultraviolet rays?

The primary precursor for the production of cholesterol in our body is