<span>DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.</span>
Answer:
Species are adapted to their environments. By understanding the interactions within an ecosystem, scientists can develop an understand of how populations evolve (develop gradually) in response to their environment.
Answer:
Due to the earth's rotation and the gravitational pull of the moon.
The correct answer is:
D
.Villi in the small intestine have thin-walled capillaries to make the absorption of nutrients more efficient.
Explanation:
The small intestines are well adjusted for absorbing nutrients during digestion by being very long, having villi and microvilli that enlarge surface area, using muscular contractions to move and mix food, and raising and housing digestive enzymes and bile that aid the breakdown of food. The inner surface of the small intestine is not flat but thrown into circular folds, which not only enhance surface area but aid in preparing the ingesta by acting as baffles. Villi: the mucosa makes multitudes of ridges which project into the lumen and are satisfied with epithelial cells.
