Answer:
Hilum.
Explanation:
Hilum may be defined as the type of the depression or the fissure and may present in kidney known as kidney hilum, present on spleen and the lungs. This is also known as hilus.
The hilum marks the entry and exit of the nerves and the blood vessels. The lung hilum is a triangular like depression through which the blood vessels, capillaries and the nerves enter and leave in the lungs and connects the other organ of the body.
Thus, the correct answer is option (d).
Starvation.
Disease.
Weather.
Lack of mate.
Offspring dying.
Hunting.<span />
Respiratory system and the cardiovascular system
The number of amino acids that will be in the polypeptide chain produced by the normal DNA or MRNA sequence is usually 30 amino acids. Although the number of amino acids depends on the function of the generated DNA or RNA. The types of amino acids also differ depending on the function.