Answer:
Option (4).
Explanation:
Respiratory system may be defined as the system involves in the exchange of gases between the tissue, lungs and the outside environment. The respiratory system involves nose, mouth, larynx, trachea, lungs, brochi, alevoli and alveolar ducts.
The oxygen is inhaled in the body and carbon dioxide is exhaled out from the body. The oxygen is transferred into the blood stream by binding of oxygen with hemoglobin. The oxygen is diffused in to body due to the partial pressure difference of oxygen and carbon dioxide.
Thus, the correct answer is option (4).
The answer is B The crust provides raw materials necessary for life.
No, predators do not only kill the old and sick prey. They will go after any of the prey, including the strong ones and the children. The reason they often go after the old and sick prey is because they're easier to pick off, whether they are on their own or in a pack. Predators will go after any one of the members of their prey, but prefer the old and/or sick as it requires less energy.
Mutation is the primary cause of all genetic variation. Mutation is important as the first step in evolution, as it produces a new sequence of DNA for a particular gene, producing a new allele. Recombination, through intragenic recombination, may also generate a new DNA sequence (a new allele) for a particular gene.
False.
It can either be called Dependent or Independent variable.
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