Mechanical stress applied to bone increases osteoblast activity in bone tissue, and the removal of mechanical stress decreases osteoblast activity.
Explanation:
Osteoblasts are cells , that are produced in the bone marrow and are responsible for formation of bones and bone matrix.
Whenever a mechanical stress is applied on the bones , a series of reactions are triggered. As a result the activities of osteoblast increases to synthesize more and more bone matrix to provide strength.
Again on the other hand a decrease in mechanical causes a decrease in the activities of the osteoblasts.
Answer:
Thymine
Explanation:
Nitrogen base found in DNA not RNA
"Have a good day." - Nahiku
Skeletal muscle just attach to the skeleton of the body by itself.
It’s is reproduced by fragmentation,budding or producing spores hope it helps!
Lets understand the given passage.
An ecologist <u>observes that the diet of a bird species consists primarily of large grass seeds</u> (as opposed to smaller grass seeds or the seeds of other herbaceous plants found in the area).
<u>He hypothesizes that the birds are choosing the larger seeds because they have a higher concentrations of nitrogen than do other types of seeds at the site</u><u>.</u>
<u>To test the hypothesis, the ecologist compares the large grass seeds with the other types of seeds, and the results clearly show that the large grass seeds do indeed have a much higher concentration of nitrogen.</u>
No, he cannot conclude that the birds select the larger grass seeds because of their higher concentrations of nitrogen. The hypothesis testing done by the ecologist is incomplete as he failed to set up a control in the experiment. The control would have been the birds feeding on large seeds that lack or are low on nitrogen content. This will establish a relation between the bird's diet and the size of the seeds and the nitrogen content of the seeds. It could be true that birds do not care about the nitrogen content but simply prefer larger seed sizes.
Another problem associated with his field experiment is the failure in noting the beak sizes of the birds. The beak size and shape enable a bird to break and eat seeds. Larger beaks fail at breaking open smaller seeds. This observation would add bird beak size as another variable of the experiment.
