Answer:
The research shows that for the cortex to evolve to be large, primates need a longer pregnancy, whereas a longer childhood is needed for a larger cerebellum to evolve. This means it is critical for infants to have the right environment to develop crucial skills.
Explanation:
Answer:
Parotid glands are the largest salivary gland. Each gland is approximately 6 cm long and 3-4 cm wide and can weigh up to 30 grams. They are located within each of our cheeks. In our oral cavity they are responsible for the secretion of about 20% of saliva. This saliva is known as serous i.e. more liquid and fluid. It helps in the first phase of the digestion of food, facilitate mastication "chewing". These glands secrete protein-rich fluid which is a suspension of alpha-amylase enzyme.
Lactase refers to an enzyme that can dissociate lactose sugar into glucose and galactose. This enzyme plays an important role in the digestion of milk that comprises high lactose sugar. In case, if a mutation occurs in the gene codon of lactase, then two possibilities can take place. These are as follows:
1. Loss of mutation: In this case, the person becomes lactose intolerant because of mutation in lactase gene codon. Due to this, there is low mRNA expression and thus low production of the enzyme lactase. This is also known as lactase non-persistent phenotype.
2. Gain in mutation: In this case, the person gain an increase in mRNA expression of the lactase gene, thus more production of lactase takes place than usual. This kind of individual exhibits lactase persistent phenotype.
Answer:
Oxygen molecules in the tissues of the lung diffuse into the blood because the concentration of oxygen in the lung's tissues is more than the concentration of oxygen in the blood.
Explanation:
Diffusion is the movement of molecules from the region of higher concentration of the molecule to the region of lower concentration of the same molecule. Molecules in diffusion move <em>downward the concentration</em> <em>gradient</em> created by difference in concentration between two regions until an <em>equilibrium (equal concentration in the two regions)</em> is established.
Oxygen molecules diffuse into the tissues of the lung when an organism breathes-in during the process of breathing. The molecules in the now oxygen-rich tissues eventually start diffusing into the blood in the lung because the blood passing through the lung is always de-oxygenated or has lower oxygen concentration compared to the tissues of the lung.
Oxygenated blood moves into the heart, pumps round the body by the heart, gets depleted of oxygen and eventually find its way back to the lung where the process is repeated.
Diffusion of oxygen from the tissues of the lung into the blood will keep happening as long as oxygen keeps getting dissolved into the lung's tissues and an equilibrium is yet to be established between the tissues and the blood.
