The conversion of ammonium salts into nitrates is called_______
putrefaction
denitrification
fixation
nitrification
Correct answer is D
No explanation has been provided for this answer.
Tooth decay is usually caused by___________
undigested and absorbed food
eating a limited amount of sweetened food.
the bacteria ín the mouth that metabolize sugar to acids
eating a lot of proteinous foods
Correct answer is C
No explanation has been provided for this answer.
The digestion of proteins starts in the______
small intestine
stomach
large intestine
mouth
Correct answer is B
No explanation has been provided for this answer.
The major mineral present in the shell of Molluscs is________
Copper
Sodium
Iron
Calcium
Correct answer is D
No explanation has been provided for this answer.
Light is excluded from a water culture experiment in order to________
prevent overheating of the roots
enable the roots to grow straight down
prevent ionization of water molecules
prevent the growth of algae
Correct answer is C
No explanation has been provided for this answer.