Answer:
a
Explanation:
this is because it is sharing in the food that is meant for the organism
Blood first enters the heart's right atrium. A muscle contraction forces the blood through the tricuspid valve into the right ventricle. When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery. Then it travels to the lungs
EARTH'S PROTECTIVE SHIELD. Earth is surrounded by invisible gases that form a thin protective blanket that we call the atmosphere. It contains the oxygen that we breath as well as other important gases such as nitrogen, carbon dioxide, water vapor, and ozone.
The evolution of the peppered moth evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial revolution .The frequency of dark-coloured moths increased at that time, an example of industrial mellaniam. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin natural selection in action, and remains as a classic example in the teaching of evolution.