Blood flows to the brain through the internal carotid and vertebral arteries and away from the brain through the internal jugular vein. The internal carotid artery supplies the brain, while the external carotid nourishes other portions of the head, such as the face, skull, scalp and the meninges. The vertebral arteries provide supply to the upper spinal cord, brainstem, cerebellum, and the posterior part of the brain.
Answer and explanation;
-Strong acids and bases are defined as compounds that completely ionize in water or aqueous solution. Weak acids and bases only partially dissociate.
A strong acid will fully dissociate in water to form H+ ions.
HCl + H2O---> H3O+ + Cl-
This reaction is non-reversible. After dissolution, only a very very minute concentration of HCl itself remains in the solution, as most of the diluted HCl has dissolved into ions.
Ka = [H+] [Cl-] / [HCl]
The same applied for bases. The only difference is that the base dissociates to form OH- ions instead.
Strong and weak bases will depend likewise on whether the reaction is reversible.
A strong base will completely dissociate to give more OH- ions.
An example of a strong base;
NaOH + H2O ---> Na+ + OH- + H2O
Kb = [Na+] [OH-] / [NaOH]
Ans.
Human reproduction involves release of sperm (male gamete) and egg (female gamete) and their fusion to form zygote that develops into embryo. In females, an egg is released each month as a part of a monthly cylce, called menstrual cycle. The release of egg is termed as ovulation, in which tiny eggs are send into the fallopian tubes for fertilization.
Hence, the correct answer is 'a). an adult female usually releases an egg from an ovary each month.'
Yeast food is sugar and its concentration affect yeast’s growth and activity. The process by which yeast metabolize sugar is called fermentation. A sugar concentration that is not very high (up to 3%), increase the fermentation rate. But, with over 3% sugar, the fermentation rate no longer increases. Above 6%, sugar actually decreases the rate because it begins to dehydrate the yeast cells. This effect is called crenation.
