Second hand smoke is more dangerous than smoke inhaled

Maintaining a healthy weight allows the respiratory system to work more effectively because a. oxygen is being delivered more adequately. b. the heart does not have to pump as forcefully. c. the capillaries are constricted. d. the lung capacity allows for small amounts of air.

Which of the following is characteristic of the lytic cycle? a) viral dna is incorporated into the host genome.b) the viral genome replicates without destroying the host.c) a large number of phages are released at a time.d) the virus—host relationship usually lasts for generations.

What nutrients prevent osteoporosis? a. all vitamins and minerals b. calcium, vitamins c, d, and k, and magnesium c. protein d. carbohydrates