To accurately measure the density of a series of small irregular solids made of plastic, wood, fibreglass, and glass, a student will need which of the following laboratory tools?

An efferent neuron that is responsible for releasing a neurotransmitter that stimulates a muscle cell to contract is a motor neuron ². Motor neurons carry signals from the brain to the peripheral nervous system in order to initiate an action. The neurotransmitter acetylcholine (ACh) is released by motor neurons at the neuromuscular junction in skeletal muscle, causing the muscle to contract ³.

The other options are incorrect because they do not accurately describe the type of neuron responsible for releasing a neurotransmitter that stimulates a muscle cell to contract. Interneurons are found within the central nervous system and facilitate communication between sensory and motor neurons. Sensory neurons carry information from sensory receptors to the central nervous system. Neuroglia are support cells for neurons and do not transmit nerve impulses.

The correct answer is a. Nuclei. Genetic information describing the characteristics of an organism is found in the nuclei of its cells. The nucleus contains the organism's DNA, which carries the genetic information that determines its traits.

b. Membranes are structures that surround and enclose cells and organelles, but they do not contain genetic information.

c. Cilia are hair-like structures that protrude from the surface of some cells and are involved in movement, but they do not contain genetic information.

d. Ribosomes are organelles that are involved in protein synthesis, but they do not contain genetic information.

The triple point of a substance is the temperature and pressure at which the substance exists simultaneously in solid, liquid, and gas phases ¹. In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.

The other options are not correct because they do not accurately describe the triple point of a substance. Sol, gel, and plasma are not phases that coexist at the triple.

The parotid gland is an exocrine gland that secretes saliva into the mouth. Exocrine glands secrete their products into ducts that carry the secretions to the body's surface or into body cavities. The other options are endocrine glands, which secrete hormones directly into the bloodstream. The pineal gland secretes melatonin, the parathyroid glands secrete parathyroid hormone, and the pituitary gland secretes several hormones that regulate various bodily functions.

The correct answer is a. Soap’s dual polar and nonpolar nature helps bond oil and water. Soap is an emulsifier, which means that it has both polar and nonpolar regions. The polar regions of soap molecules are atracted to water, while the nonpolar regions are atracted to oil and grease. This allows soap to bond with both water and oil, helping to remove dirt and grime from surfaces.

B. Soap’s acidity does not cause grime to precipitate into the water.

C. Soap does not have enzymatic action that helps to dissolve grime into small particles.

D. Soap’s texture does not physically scour grime off surfaces.

The correct answer is d. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. The pH scale is a logarithmic scale, which means that each change of one pH unit represents a tenfold change in the hydrogen-ion concentration. A substance with a pH of 3 has a hydrogen-ion concentration that is 10 times greater than that of a substance with a pH of 4.

A. A substance with a pH of 3 is not two times more alkaline than a substance with a pH of 4.

B. A substance with a pH of 3 is not 10 times more alkaline than a substance with a pH of 4.

C. A substance with a pH of 3 is not two times more acidic than a substance with a pH of 4.

The correct answer is a. Storage of minerals. Bones serve as a storage site for minerals such as calcium and phosphorus. These minerals are essential for various bodily functions and can be released from the bones into the bloodstream when needed.

b. Detoxification of alcohol is not a function of bone. This process occurs primarily in the liver.

c. Secretion of hormones is not a function of bone. Hormones are produced and secreted by glands such as the pituitary gland, thyroid gland, and adrenal glands.

d. Production of otoliths is not a function of bone. Otoliths are small calcium carbonate structures found in the inner ear of fish and other vertebrates that help with balance and hearing.

The apocrine gland is a component of the integumentary system that secretes pheromones. Pheromones are chemical signals that are released by an individual and can affect the behavior or physiology of other individuals of the same species.

The other options are not components of the integumentary system that secrete pheromones. The fossa ovalis is a depression in the interatrial septum of the heart, the seminiferous tubule is a structure in the testes where sperm are produced, and the dermal papilla is a structure at the base of a hair follicle that provides nutrients to the hair.

The correct answer is c. Data are biased by the methodology. The researcher's data should be rejected because they are biased by the methodology used to gather them. By only using a small net, the researcher excluded all large birds from the study. This means that the data do not accurately represent the average wing strength of all birds found in the American Northwest.

A. The data contradicting the control group is not a reason to reject the data in this case.

B. The data being different than expected is not a reason to reject the data in this case.

D. The data not being able to be displayed graphically is not a reason to reject the data in this case.

Air resistance could be greater for A than for B.

Since both objects have the same mass but different times of fall, it suggests that there could be differences in air resistance affecting their fall rates. Object A took longer to fall, indicating that it might have experienced more air resistance compared to Object B.