Valves in veins are formed of the tunica media. cause venous blood flow to go in only one direction. are found only in the largest veins. make the use of a skeletal muscle pump unnecessary for venous blood flow. are the leading cause of high blood pressure.

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

ya the other dude is right

linnaeus is the father of taxonomy, which is the system of classifying and naming organisms. one of his contributions was the development of a hierarchical system of classification of nature. today, this system includes eight taxa: domain, kingdom, phylum, class, order, family, genus, and species.

point counts

mark brainliest!