If two people have vaginal sex standing up, then pregnancy is not possible because the sperm will just fall out. Myth
Fact

Some viruses can be crystallized and their structures analyzed. one such virus is yellow mottle virus, which infects beans. this virus has a single-stranded rna genome containing about 6300 nucleotides. its capsid is 25-30 nm in diameter and contains 180 identical capsomeres.if the yellow mottle virus begins its infection of a cell by using its genome as mrna, which of the following would you expect to be able to measure? a) replication rateb) transcription ratec) translation rated) formation of new transcription factors

Viruses use the host's machinery to make copies of themselves. however, some human viruses require a type of replication that humans do not normally have. for example, humans normally do not have the ability to convert rna into dna. how can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires? a) the virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles.b) the viral genome codes for specialized enzymes not in the host.c) the virus infects only those cells and species that can perform all the replication roles necessary.d) viruses can stay in a quiescent state until the host cell evolves this ability.

Explain why hiv is a life-threatening sti.