In fetal life, the lungs are not expanded, so most of the blood from the right ventricle is shunted from the pulmonary artery to the aorta through the patent ductus arteriosus. With a few breaths the lungs expand, and blood flows from right ventricle to pulmonary artery into the lungs. Withdrawal of circulating prostaglandin from the mother plus bradykinins released from the expanding lung of the infant cause the ductus to close over a few minutes to hours. The closed ductus remains as the ligamentum arteriosum.
Answer and Explanation:
<em>IMPORTANT NOTE: Due to technical problems, you will find t</em><em>he answer and the complete explanation</em><em> in the attached file.</em>
Answer:
a. Centromere
A centromere is a specialised DNA sequence of a chromosome that links pair of sister chromarids (a dyad)
Answer:
the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.
Answer:
Slow-twitch
Explanation:
Red meat is rich in slow-twitch muscle fibers. The slow-twitch muscle fibers are rich in myoglobin and blood capillaries. They also have many large mitochondria to generate ATP by aerobic respiration.
These fibers are slow-twitch fibers as the ATPase in myosin head carries out the hydrolysis of ATP at a slower rate causing a slower contraction cycle.
Slow-twitch fibers appear red due to a large amount of myoglobin and a rich network of blood vessels. They are capable of prolonged contractions and are fatigue resistant.
