Answer:
The color of skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis.
ANSWER:
food boxes
plastic bottles few of them
plastic bags
This question is incomplete as the specific food chain is not provided. In general, a food chain will have a primary producer at the base of the chain. This is an organism that is able to utilise a form of energy to convert carbon dioxide in the atmosphere to a carbohydrate. For terrestrial food chains, these are typically plants, who by utilising the energy from the sun, are able to convert carbon dioxide to carbohydrates. The subsequent level in the food chain may be a primary consumer, typically herbivores, that consume plant matter. Subsequent links in the chain would typically be secondary consumers, who would be carnivores, omnivores or decomposers. Carnivores would typically be predators and would be at the apex of the food chain. Energy is lost from one link to the subsequent link in the food chain, through basic respiration and inefficient energy transfer from one link to another. This explains why more resources (land, water and air) are required to grow meat rather than plant matter. More of the sun's energy is available within the lower trophic levels in a food chain, before much of it is lost as energy moves up the food chain. An easy example to illustrate this is that much of the livestock raised in the USA is fed grain. If people rather ate the grain than the livestock, they could obtain all their required energy from a smaller amount of grain then would be needed to raise the meat they require.
Answer:
Las células madre son células que se reproducen constantemente y tienen la capacidad de transformarse en cualquier otro tipo de célula del cuerpo de un organismo. Una célula a partir de la cual pueden crecer todos los tejidos del cuerpo, o una gran parte de ellos, es obviamente una célula extremadamente útil.
Si las células madre se guían en la formación de tejidos sanos y funcionales, entonces, potencialmente, la terapia celular podría aplicarse para muchas enfermedades. De hecho, si las células provienen del propio paciente, en teoría no habrá riesgo de su rechazo (como lamentablemente ocurre con los trasplantes).
Las células madre tienen la capacidad de reproducirse por sí mismas a través del proceso de mitosis celular, para crear copias idénticas (clones) de sí mismas..
Scientists<span> are people who use research and experiments to learn more about the natural world. </span>Scientists<span> use scientific methods to derive knowledge systematically, performing repeatable experiments to ensure that their conclusions are valid and accurate.</span>
