Immunodeficiency occurs when the immune system is not working properly, and hIV, the human immunodeficiency virus, is a retrovirus. Given these facts, what causes the immune system to not work properly among the following options: - HIV - lack - DDT - p53 - antibiotics - h2o - memory cells - HPV
HIV

Mutations that lead to cancer usually occur in genes that control the cell cycle, and cancer is an example of a mutation in cells. Given these facts, what usually occur in genes that control the cell cycle among the following options: - Leptospirosis - competition - A Greek letter - a mutation in cells - Plant reproduction - biological diversity - resistance - resistance activities
a mutation in cells

Hitting an object causes the particles in that object to vibrate, and by it's nature, a vibration is a frequency wave . Given these facts, what does hitting an object cause among the following options: - frequency waves - harmful substances - Electrical energy - chemical reaction - friction - Movement - heat energy - chemical changes
frequency waves