Hydroxyapatite is the major component of bone that contributes to its hardness.
Answer:
B. hormone
Explanation:
The endocrine system involves many organ systems and hormones, many of which are still being investigated and understood.
Orbicularis oris
The orbicularis oris muscle is positioned surrounding the mouth and within the labia. It acts to control the movement of the lips.
Answer:
Eukaryotic cells have a true nucleus, which means the cell's DNA is surrounded by a membrane. Therefore, the nucleus houses the cell's DNA and directs the synthesis of proteins and ribosomes, the cellular organelles responsible for protein synthesis. ... In eukaryotes, chromosomes are linear structures.
Explanation:
Chameleons, those shade-shifting, intricately camouflaged lizards that can change color in response to environmental or behavioral influences. Since the oldest lineages of chameleons are all from Madagascar, scientists believe they evolved on the island and spread out from there. As far as paleontologists can tell, the first chameleons evolved shortly after the extinction of dinosaurs 65 million years ago. Unlike other animals that change color, such as the squid and octopus, chameleons do not modify their hues by accumulating or dispersing pigments within their skin cells, the researchers found. Instead, the lizards rely on structural changes that affect how light reflects off their skin, the researchers said. Although chameleons are believed to have originated in Africa or Madagascar, the oldest known fossil, 26 million years old, is Chamaeleo caroliquarti from western Bohemia.