Many mountains have a tree line, which is an imaginary line above which trees will not grow. Hypothesize why some mountains have tree lines and what the trees at the tree line might look like.

Hemoglobin is the compound in red blood cells that carries oxygen to the body. the distribution of hemoglobin in women in g/dl of blood is approximately normally distributed with mean 14 and standard deviation 1. too little hemoglobin, and you're anemic. 2. too much, and (unless you live at high altitudes), you can have other problems.

What is an endocrine function? (apex) a. esophageal glands release mucus into the esophagus b. salivary glands release saliva into mouth c. swear glands release sweat to the skin d. the pineal gland releases melatonin into the bloodstream

The chromosomal structure that limits the number of cell divisions of a cell is the the chromosomal structure that limits the number of cell divisions of a cell is the kinetochore telomere histones centromere