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.
Answer: D. The kinds of organisms that lived there long ago.
Explanation: Finding fossils in an area can help us learn about the kinds of organisms that lived there long ago. The fossil leave traces behind about what type of animal lived there and who the animal was.
The answer would be C because iron is magnetic
Answer:
Arrows :
It shows how energy and nutrients are transferred from plants (producers) to herbivores and carnivores and through to decomposers. ... The arrows in the food chain below depict the direction in which energy and nutrients flow, i.e. the arrow always points from the eaten to the eater.
Greatest amount of energy transferred: Grass aka Autotrophs.
A sequence of living organisms which involves the transfer of food energy from producers, through a series of organisms with repeated eating and being eaten is called food chain. Each level or step in a food chain where the transfer of energy takes place is called trophic level. According to the pyramid of energy, the energy content is maximum in autotrophs or producers. Autotrophs are the plants which prepare their food by photosynthesis. They are the primary producers and primary source of food energy. The flow of energy is unidirectional from producer to consumer level. The energy decreases at each trophic level of the food chain, as part of the energy is lost as heat and major part of the energy is liberated during respiration for use in various activities. Only 10% of the energy of previous trophic level is received by next trophic level, as proposed by 10 percent law of Lindeman.
