Smallpox viruses can replicate only inside a human cell. Human influenza viruses can replicate in human cells and in the cells of pigs and some other animals. How might this difference influence the success of vaccination programs?

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

answerpalpalis group;

in addition to being able to metabolize, grow, digest food, and excrete wastes, what other functions must an organism perform if it is to survive? survival also depends on the ability to maintain one's boundaries, to move, to respond to stimuli, and to reproduce. oxygen is a survival need.