The aveolus is surrounded by capillaries. So capillaries carry deoxygenated blood to the alveolus where the oxygen from the alveolus diffuses into the blood in the capillaries. The deoxygenated blood is now oxygenated and is carried out of the lung via capillaries that then merge into the pulmonary vein.
In other words, alveolus does not have oxygenated blood it just puts oxygen into the deoxygenated blood hat this brought in.
To help your immune system prepare for diseases
They have more access to development, large factories, and more cars. industrialized nations frequently have a higher population
Answer: For flowering plants, fertilization occurs through a process known as double fertilization. Unlike most plants, double fertilization enables the new seed to grow into a new plant and have a food source to begin growing. Double fertilization occurs within the female part of a plant, the pistol.
explanation: When pollen is formed by the anther, or male part of a plant, it will blow in the wind or attach to an organism that carries it to the top of the pistol, known as the stigma. Once the pollen attaches to the stigma, the pollen germinates and forms a pollen tube that extends into the ovary. Once formed, two sperm cells will be released and fertilize both the egg and the two polar nuclei of the plant to form the zygote and endosperm, respectfully.