The testing of a hypothesis in duplicate with only one factor being different
controlled experiment
2. an assumed explanation for a problem
hypothesis
3. a recognized means of inquiry to provide scientific answers to questions
scientific method
4. supported by evidence gathered over a period of time
theory

sex cells are usually half's then they find another half and make a fertilize egg

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.