Autotrophs and Hetrotrophs
Answer and explanation;
-Stem cells, Adult stem cells and skin cells , have a similarities and they may also differ in a number of ways.
-A stem cell has not gone through the process of differentiation, so they have the potential to become any type of cell.
-Adult skin cells have gone through differentiation and cannot become another type of cell. Same case applies to the skin cells, they have already undergone differentiation;
-Similarity; The cells that are taken from the same person would have the same DNA.
-Difference; The skin cells and the adult stem cells have already gone through differentiation, whereas embryonic stem cells have not. The different genes that the types of cells have are turned on and off causing the differences.
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.
Hello! the answer is B.Gametangium
Developing Nations currently produce about 2600 kcal of food per person per day. The growth in food consumption around the world has been accompanied by a significant structural changes and a shift in the diet away from the staple foods such as roots and tubers towards more livestock products and vegetable oils.
