|
|
Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
Drug abusers experience the following scenario: The pleasure given by their drug (or drugs) of choice is so strong that it is difficult to eradicate even after years of staying away from the substances involved. Certain triggers may cause a drug abuser to relapse. Research shows that long-term drug abuse results in significant changes in brain function that persist long after an individual stops using drugs. It is most important to realize that the same is true of not just illegal substances but alcohol and tobacco as well.
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.
![Intradermal drug administration: (a) cross section of skin showing depth of needle insertion Source:](https://biology-forums.com/gallery/47/medium_46687_08_12_14_4_59_34_19526512.jpeg)
![To search for the Native American family would be fruitless. There are rural, urban, single-parent, ...](https://biology-forums.com/gallery/27/medium_482573_20_04_17_12_17_32_27926142.png)