Compare the productivity of terrestrial and aquatic ecosystems against the percent of Earth’s surface area they occupy.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.

voluntary muscles are controlled by the cerebellum.