Answer the following question given this paragraph: The chemical reactions that regulate the levels of CO2 and carbonic acid occur in the lungs when blood travels through the lung's pulmonary capillaries. Minor adjustments in breathing are usually sufficient to adjust the pH of the blood by changing how much CO2 is exhaled. In fact, doubling the respiratory rate for less than 1 minute, removing "extra" CO2, would increase the blood pH by 0.2. This situation is common if you are exercising strenuously over a period of time. To keep up the necessary energy production, you would produce excess CO2 (and lactic acid if exercising beyond your aerobic threshold). In order to balance the increased acid production, the respiration rate goes up to remove the CO2. This helps to keep you from developing acidosis. The body regulates the respiratory rate by the use of chemoreceptors, which primarily use CO2 as a signal. Peripheral blood sensors are found in the walls of the aorta and carotid arteries. These sensors signal the brain to provide immediate adjustments to the respiratory rate if CO2 levels rise or fall. Yet other sensors are found in the brain itself. Changes in the pH of CSF affect the respiratory center in the medulla oblongata, which can directly modulate breathing rate to bring the pH back into the normal range. Hypercapnia, or abnormally elevated blood levels of CO2, occurs in any situation that impairs respiratory functions, including pneumonia and congestive heart failure. Reduced breathing (hypoventilation) due to drugs such as morphine, barbiturates, or ethanol (or even just holding one's breath) can also result in hypercapnia. Hypocapnia, or abnormally low blood levels of CO2, occurs with any cause of hyperventilation that drives off the CO2, such as salicylate toxicity, elevated room temperatures, fever, or hysteria. Q: What is the term for abnormally low blood levels of carbon dioxide? Choices: - spirogyra - hepatitis - trichina - hypocapnia A:
hypocapnia
(Question)
Answer the following question given this paragraph: The DNA of a chromosome is encoded with genetic instructions for making proteins. These instructions are organized into units called genes . Most genes contain the instructions for a single protein. There may be hundreds or even thousands of genes on a single chromosome. Q: What are the organized instructions within dna for making proteins called? Choices: - clones - genomes - replicants - genes A:
(Answer)
genes
Ques: Answer the following question given this paragraph: By losing an electron, the sodium atom becomes a sodium ion. It now has more protons than electrons and a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na + . Q: Ions can be formed when atoms lose what other particles? Choices: - neutrons - protons - shells - electrons A:
Ans: electrons
(Q).
Answer the following question given this paragraph: Elements are pure substances that make up all matter, so each one is given a unique name. The names of elements are also represented by unique one-, two-, or three- letter symbols. Q: Elements are pure substances that make up what? Choices: - some matter - Objects - Solids - all matter A:
(A).
all matter
Ques:Answer the following question given this paragraph: A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14. Q: Is an acid lower or higher than 7 on the ph scale? Choices: - exactly 7 - higher than 7 - twice as much as 7 - lower than 7 A:

Ans:lower than 7
Ques:Answer the following question given this paragraph: The brains of all mammals have a unique layer of nerve cells covering the cerebrum. This layer is called the neocortex (the pink region of the brains in Figure above ). The neocortex plays an important role in many complex brain functions. In some mammals, such as rats, the neocortex is relatively smooth. In other mammals, especially humans, the neocortex has many folds. The folds increase the surface area of the neocortex. The larger this area is, the greater the mental abilities of an animal. Q: What is the unique layer of nerve cells covering the cerebrum in mammals' brains called? Choices: - the midbrain - the neural - cerebral cortex - the neocortex A:

Ans:
the neocortex