The order of flow of oxygen within the human body may be described simply. Oxygen first is inhaled through the nasal cavity and then passes through the trachea, through the bronchi and into the lungs. In the lungs, the oxygen is passed into the blood stream through the alveoli and then is carried to the heart. The heart pumps this oxygenated blood throughout the body, primarily to organs and muscle cells, where it is consumed in respiration and is converted to carbon dioxide and excreted.
Answer:
D. the nucleus contains the protons and neutrons which takes up most of the mass of the atom
Explanation:
The nitrogenous bases Adenine form two hydrogen bonds with thymine and the cytosine form three hydrogen bonds with the guanine. Simply, A combines with T and G combines with the C. It is often called as a complementary base pairing because of each base pair bonds only with its specific complementary base partner in a DNA molecule.
Explanation:
The animals that remain active during the day are called the diurnal while animals that remain active during night are called the nocturnal.
As per the question we can distinguish organisms and plants and see their behavior during the day as well as during night. Diurnal are organisms that activate during the day, while the organisms that activate during the night are called the nocturnal. Among the animals, nocturnal animals are bats, mouse, hedgehog, etc. The appearance of the nocturnal animals is due to the following three factors :
-- to avoid heat
-- to hunt
-- to mate
