Answer:
three evolutionary lines
Explanation:
The Hox genes are master developmental genes found in animals, which are involved in the regulation of development by specifying the body plan of an embryo along the head-tail axis. Recently, several research groups studied the assortment of the Hox genes in three different marine organisms: 1- a priapulid worm (an unsegmented marine worm), 2- a brachiopod (phylum Brachiopoda), and 3- a polychaete worm (related to earthworms). Then, these research groups combined their research efforts to compare the assortment of the Hox genes observed in these species to those observed in previously studied animals including, among others, mice, fruit flies and sea urchins. From this combined study, researchers concluded that the animal kingdom can be divided into three primary evolutionary lineages.
Hawks typically eat mouses, voles, rats, squirrels, and rabbits.<span />
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A bacterium called Vibrio cholerae causes cholera infection. The deadly effects of the disease are the result of a toxin the bacteria produces in the small intestine. The toxin causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).
B. Four bonds
Carbon usually form covalent bond and can form ionic or other bonds sometimes. Carbon needs four electrons to be stable so the max of bonds a single carbon atom can form is four