Plant cells have a cell wall, but animals cells do not. Cell walls provide support and give shape to plants. Plant cells have chloroplasts, but animal cells do not. ... Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present.
Bird migrations began with the recession of the glaciers during the ice age. You will notice a great increase in insects in the spring time and early summer.The birds moved North to take advantage of this increase in the food supply that followed the warming in the spring and early summer. Their reproductive organs temporarily developed so they could lay eggs and raise a family. Look at the early flush of Night crawlers in the moist times of the early rains. By mid summer most of the insects have matured, mated and died. Their eggs have hatched and turned to larva and moved underground until next spring. The shortening of the days causes the reproductive functions to decrease and signals the birds that the food will soon become scarce. They move back to the area that makes it the easiest to find food and avoid freezing. which of course is the warmer climates nearer the equator. Not all birds move past the Tropics at approximately 30 degrees. Some like Chickadees may move down from Mi or Mn or Canada only as far south as Indiana. Some migrations may be quite short. For example from the mountains down to the plains. They don't generally reproduce in the warmer winter climes they migrate to. In the spring time they migrate along paths of the retreating glaciers. As the climate warms away from the tropics the birds follow the emerging insects etc to the birds selected breeding grounds.with increased insects and longer days to feed the hatching's. It is necesary to understand why they move to cooler climates in the summer to under stand why they move to eh warmer ones in the fall. As the days shorten the food supply dwindles and the babies have fledged. They move to warmer climates in winter to rest and refuel for the next years migration.
Antibodies bind to the antigens on the surface of disease agents. If some sort of fluorescent tag is added to the antibody it would make the disease agent be identifiable either under a microscope or with other Instruments because it would bind to the antigens on the surface of the disease agents and make them glow a certain color. I hope that this is the answer that you were looking for and it has helped you.
Answer: <u>Sinks towards the outer core
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Explanation: The material which is less dense, means it is lighter in weight. Such substances tend to move more towards the crust of the Earth, whereas the heavier substances like iron, is more towards the core or centre of the Earth. This is because heavier substances tend to sink deeper. That’s why the light elements are found in the crust section of the Earth.
