B, because a scientific theory is not yet proven.
In several ways, the scientific method is similar to medical diagnosis:
In medical diagnosis, the state of the patient's health is being observed. This involves examining the patient and performing measurements like taking temperature and blood pressure, or analysing blood and urine sample.A possible explanation or hypothesis, such as the presence of a specific disease, is then proposed.
The hypothesis is tested. This involves treating the patient for the condition, for example, by administering a medicine.The patient is observed again to determine whether the proposed explanation and the treatment based on it were correct. If the symptoms disappear, the diagnosis (hypothesis) is confirmed; is not another explanation may be necessary.
Answer:
Plants and animals both are living organisms that are directly dependent on the air. The air is comprised of various gases with definite proportions such as 78% of nitrogen, 21% of O₂, 0.9% of argon, 0.03% of CO₂, and other minor gases.
Oxygen (O₂) is the main gas that is essential for life to exist. Without this gas, no organisms can survive.
The organisms inhale oxygen (O₂) gas and exhale carbon dioxide (CO₂) gas.
These gases play an important role in the lives of plants and animals as it helps in carrying out the process of respiration. This process is essential in order to generate energy in the body of the organisms where the food particles (commonly known as sugar) are disintegrated by the cells. This is how an organism respire by inhaling O₂ gas and exhaling CO₂ gas.
The right answer is inversion.
Inversion is a genetic mutation characterized by the end-to-end reversal of a portion of chromatid on a chromosome.
In other words, it is a double break then it is replaced after rotation of 180 ° of a chromosome segment (backward insertion).
We distinguish :
Paracentric inversions: The centromere in the chromosome is not included in the inversion.
Pericentric inversions: The centromere is included in the inversion which transforms a metacentric chromosome into an acrocentric chromosome.
Microorganisms such as bacteria can be removed by disinfection. Certauns substances called biocides are addes to water to make it pure. Purification can also be done by UV-light .
