What human body system is the spinal cord in?

1. which of the following is correct regarding opiates/opioids: a. they all have a natural component as a starting pointb. they have low addiction possibilitiesc. methadone binds to some of the same receptorsd. a and care correcte. all are correct

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

Which cell organelle is the site for photosynthesis? a. chloroplast b. endoplasmic reticulum c. golgi apparatus d. lysosome