Answer:
The periosteum is one source of precursor cells which develop into chondroblasts and osteoblasts that are essential to the healing of bone. Other sources of precursor cells are the bone marrow (when present), endosteum, small blood vessels, and fibroblasts.
<span>Cattle and sheep are exposed to lead and zinc when these poisons are in the grass/soil.
Cattle and sheep graze on the grass, and thus they intake these minerals, such as lead and zinc when they come in contact with grass or earth they may eat along with grass. Thus they are exposed to them via eating.
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Answer:
<em>Hello, In all the ecological pyramids, producers (organisms that produce their own food) are found at the lowest trophic level. This trophic level contains the highest amount of energy. The energy in each trophic level of an energy pyramid is just 10 percent of the energy in the level below it. (Why is there less energy available at the top of an energy pyramid than at the bottom?) Less energy is available to organisms in the upper levels because each organism releases some of the chemical energy in food to the air as thermal energy. Less total energy is available with each step up energy pyramid. Hope That Helps!</em>
<span>For bees, their forage or food supply consists of nectar and pollen from blooming plants within flight range</span>
A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment.
