HIV infects and destroys helper T cells, and hIV, the human immunodeficiency virus, is a retrovirus. Given these facts, what does the human immunodeficiency virus destroy among the following options: - B cells  - bacteria  - helper T cells  - animals  - epidermis and dermis  - critical organs  - an organism's body  - cancer cells
helper T cells

Cell division is how organisms grow and repair themselves, and humans are complex organisms. Given these facts, what uses cell division to grow and repair themselves among the following options: - animals  - humans  - plants  - trees  - volume  - battery cells  - ferns  - density
humans

Amutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring, and mutations are accidental alterations of the genetic code in a cell. Given these facts, what can appear due to accidental alterations of the genetic code in a cell among the following options: - symptoms  - hyperthyroidism  - Plastic cell membranes  - Metallic DNA  - Groupings of nano-cells  - New traits  - disease  - viruses
New traits

Blood pH may become unbalanced if the rate of breathing is too fast or too slow, and mammals breathe with lungs. Given these facts, what may become unbalanced if the lungs are working too fast or too slow among the following options: - Decibels  - hair on head  - air pressure  - gasoline levels  - Acids  - energy usage  - brain chemistry  - blood pH
