Answer: C. Birds moving south when the weather gets colder
Seasonal change is the change in season due to change in abiotic factors like weather conditions, sunlight availability, wind direction etc. Seasons change from summer to winter, winter to summer, summer to spring etc. These seasonal changes affect the life of biological communities including plants and animals. Some organisms adapt to changing seasonal conditions but others completely avoid them by migrating to other places where weather conditions are suitable for their survival. Therefore, birds moving south when the weather gets colder is because of seasonal change as birds cannot tolerate cold weather conditions.
Answer:
A. Respiration
Explanation:
The process in which oxygen atoms are made available to the cell of animals is called cell respiration. In cell respiration the food molecules undergo process which is called food oxidization, that make it available to be absorbed by the animal cell.
The nervous system<span> is like a highway along which </span>your <span>brain sends and receives information about what is happening in the body and around it. This highway is made up of billions of nerve cells, or neurons (say new-rons) which join together to make </span>nerves<span>. A nerve is a fibre that sends impulses through the body.</span>