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.
Water molecules have covalent bonds. Each molecule consists of two hydrogen and oxygen covalent bonds. However, when water molecules are placed together, as they are normally, the hydrogen atoms in each molecule can form hydrogen bonds with the oxygen atom of other molecules.
An oven mitt is used to take the tray out of the oven because its insulated, or padded.
Answer:plate tectonics
Explanation: Because plate tectonics moved around the continents and they were moved to different locations which caused the climate change
Answer:
Explanation:
Proteins are involved in almost every function of cell and inside the body and each protein is specific for its role. Some of them are
1) Protein constitute major part of structure of cell. Proteins are major constituent of cell membrane along with lipids.
2) Enzymes which are proteins in nature catalyze all the important chemical reactions inside and outside the cell e.g transporting material across the cell, synthesizing and repair of DNA
3) Hormones which are proteins play important role in the regulation of metabolic reactions inside the cell
4) Regulation of cell division is performed by DNA-associated proteins
5) Proteins plays important role in storage of iron inside the cells
6) Proteins can be stored as fats inside the body and used as energy when needed by cells for its metabolic activities.
