I would chose the 4th one because biome is made up of a bunch of little biospheres
The answer is A. I'm sure about this
1. Family 2. Order 3. Class 4. Kingdom
Two types of genes play a major role in regulating the cell cycle. Genes called proto-oncogenes encourage cell division. Proteins produced by these genes act like accelerators stimulating the cell to grow and divide. In contrast, genes called tumor-suppressor genes inhibit cell division.
DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode.
