The answer is that Both aid in the expansion and relaxation of lungs. Diaphragm and the rib muscles are vital in the breathing process. During inhalation the intercostal muscles contract, expanding the ribcage, the diaphragm contracts, pulling downwards to increase the volume of the chest, pressure inside the chest is lowered and air is sucked into the lungs. During exhalation the intercostal muscles relax, the ribcage drops inward and downwards, the diaphragm relaxes, moving back upwards, decreasing the volume of the chest, the pressure inside the chest increases and air is forced out.
Answer: False
Explanation:
Protozoans are not the organism that fix nitrogen for the plants. The organism that fix nitrogen to convert it into a form which can be used by plants are known as diazotrophs.
These are bacteria and archae that fix nitrogen gas found in the atmosphere into more usable form such as ammonia.
These organism can grow without any external source of fixed nitrogen. Example: Rhizobia and azospirillium.
Answer:
Saudi Arabia, Russia, the United States, and Iran
Explanation:
Answer:
C. disruptive natural selection
Explanation:
Disruptive selection is a type of natural selection in which extreme phenotypes are favored over intermediate phenotypes in a population. Environmental change is a major factor that can bring about disruptive selection. The individuals with the extreme phenotypes adapt well and are able to survive in the particular environment, while those individuals with intermediate phenotypes would hardly survive or be greatly reduced in number.
The gray rock outcrops and the brown soils of the Island favors the survival of mice with brown and gray fur color respectively. The fur colors of these two extreme phenotypes in the population of mice, have helped both varieties against Hawks as their main predators, hence establishing their existence on the Island.
