FREE PAX Science Questions and Answers
Which blood vessel carries oxygenated blood back to the heart?
Explanation:
Generally speaking, veins carry deoxygenated blood and arteries carry oxygenated blood, but there are exceptions. The pulmonary veins carry oxygenated blood from the lungs to the left side of the heart, and the pulmonary arteries carry deoxygenated blood from the right side of the heart to the lungs. The aorta takes oxygenated blood away from the left side of the heart and distributes it throughout the body. The superior vena cava returns unoxygenated blood back to the right side of the heart, to then be distributed through the lungs and reoxygenated.
What are the characteristics of the person with genes from possibility 1?
Explanation:
Possibility 1 corresponds to a person with the TR gene combination, which means the person is tall with red hair.
What is the mass (in grams) of 1.0 mol oxygen gas?
Explanation:
The mass of 1.0 mol oxygen gas is 32 grams. The molar mass of oxygen can be obtained from the periodic table. In most versions of the table, the molar mass of the element is directly beneath the full name of the element. There is a little trick to this question. Oxygen is a diatomic molecule, which means that it always appears in pairs. In order to determine the mass in grams of 1.0 mol of oxygen gas, then, you must double the molar mass. The listed mass is 16, so the correct answer to the problem is 32.
Which of the following is the most likely pH of a solution containing many hydroxide ions (OH-) and few hydrogen ions (H+)?
Explanation:
A solution that contains more hydroxide ions than hydrogen ions is a base, and bases have a pH greater than 7, so the only possible answer is choice D, 9.
What will happen to light waves as they hit a convex lens?
Explanation:
When light waves hit a convex lens, they are refracted and converge. A convex lens curves or bulges with the middle being thicker and the edges thinner. A magnifying glass is an example. Light rays are refracted by different amounts as they pass through the lens. After light rays pass through, they converge at a point called the focus. An object viewed with a magnifying glass looks bigger because the lens bends the rays inward. Choice B would indicate a concave lens as it would cause the light to be refracted and diverge.
Light is not reflected in this case, so neither choice C nor D would be applicable.
Suzanne is exploring contraception options. She is sexually active with her long-term partner but does not plan on having children for the foreseeable future, so she would prefer a long-lasting and low-maintenance method. She also would rather use a nonhormonal contraceptive. Which type of contraception is the most appropriate for her preferences?
Explanation:
A copper IUD is a 99 percent effective non-hormonal contraception that lasts up to 12 years. It is the most appropriate option since Suzanne would like a long-term solution that requires little maintenance. While progestin implants are equally effective and last up to five years, implants release the hormone progestin to prevent ovulation and obstruct sperm by thickening cervical mucus. Depo-Provera shots - also called Depo shots or birth control shots—are also 99 percent effective. However, birth control shots must be administered every three months. Female or internal condoms are less than 80 percent effective and must be used every time that a couple has sexual intercourse. Similarly, male condoms must be used every time but are slightly more effective (approximately 87 percent effective). Condoms are the only contraceptive option of those listed that also prevent STD transmission.
Which of the following is exchanged between two or more atoms that undergo ionic bonding?
Explanation:
An ionic bond forms when one atom donates an electron from its outer shell, called a valence electron, to another atom to form two oppositely charged atoms.
Jessica goes to the gym locker room after completing her workout and finds a woman lying on the ground. After she checks the scene for safety, she checks for responsiveness, breathing, and bleeding. The woman does not appear to be conscious or breathing, and Jessica cannot feel her pulse. Jessica calls 911 and places the woman on her back. Jessica is not CPR-certified. What is the next step the 911 operator should direct Jessica to take?
Explanation:
The first step a person should take when encountering a scenario like this is to call 911 and follow the dispatcher's instructions. Usually, the second step is to find an AED as it can help to guide a trained or untrained person through CPR, monitor vital signs, and administer shocks if necessary. In this situation, After checking for responsiveness, breathing, and pulse and calling 911, Jessica would most likely be guided by the operator through the use of an AED. AEDs are intended to be usable by anyone, even if the individual is not CPR-certified. The American Heart Association recommends that an untrained person administer hands-on CPR. Hands-only CPR consists of chest compressions delivered at a rate of 100 beats per minute and a depth of two inches. Blind swipes of the mouth to remove foreign objects are no longer encouraged due to the risks for further lodging the object into the airway. Conventional CPR consists of giving two breaths after every 30 compressions.
During which phase is the chromosome number reduced from diploid to haploid?
Explanation:
During meiosis I, the chromosome number is reduced from diploid to haploid. Interphase is the period of the cell cycle that occurs in between divisions of the cell. In meiosis, the homologous chromosomes in a diploid cell separate, reducing the number of chromosomes in each cell by half. Mitosis is the phase of cell division in which the cell nucleus divides. The S phase is the part of the mitotic cycle in which DNA is synthesized.
Which of the following correctly describes the trait LI, if "L" represents tallness and "|" represents shortness?
Explanation:
The trait LI describes the genotype of the person or the traits for the genes they carry. It is heterozygous because it contains a dominant gene and a recessive gene. Tallness is the phenotype of the person or the physical expression of the genes they carry because L for tallness is the dominant gene.
The adrenal glands are part of the:
Explanation:
The adrenal glands are part of the endocrine system. They sit on the kidneys and produce hormones that regulate salt and water balance and influence blood pressure and heart rate.