Answer:
There are two types of ecological succession:
Primary succession:
Primary succession occurs in areas which were previously devoid of life. There were no organisms living in this area before. For example, lands after new glaciers or volcano eruptions. Firstly, microorganisms begin to habitat this land, followed by plants like lichens, shrubs etc. Finally, complex life evolved from these.
Secondary succession:
Secondary succession arises in areas where life existed before but was destroyed due to natural circumstances like flood, fire etc. Small grasses inhabit this land first which are taken over by trees over period of time.
Answer:
Red blood cells, root hair cells in plants
Explanation:
Red blood cell: it has no nucleus. It offers the cell to carry more hemoglobin
Root hair cells in plants: they have a large cytoplasm which enables them to take water from the soil.
The correct answers are options:
1. Amphibians evolved before land reptiles.
4. Elephants appear in the fossil record after dinosaurs became extinct.
The relative dating is a technique of dating with respect to any past event. In this case, two events are discussed to be occurred in a sequence related to one-another. In the option 1, the amphibians are said to be evolved before reptiles. So, the evolution of the amphibians is relatively dated with the evolution of reptiles. Same in the option 4, the evolution of the elephants is relatively dated with the extinction of the dinosaurs.
Answer:
Explanation:
During exhalation, the diaphragm also relaxes, moving higher into the thoracic cavity. This increases the pressure within the thoracic cavity relative to the environment. Air rushes out of the lungs due to the pressure gradient between the thoracic cavity and the atmosphere.
