Use the table below to answer the question.

Which of the following conclusions is supported by the data?

Object	Mass (g)	Time of fall (sec)
A	5.0	2.0
B	5.0	1.0
C	30.0	0.5
D	35.0	1.5

 

 

The myelin sheath is a protective membrane that wraps around parts of certain nerve cells.

Its fatty-protein coating provides protective insulation for your nerve cell like the plastic insulation covering that encases the wires of an electrical cord ².

This allows the electrical impulses to travel quickly and efficiently between one nerve cell and the next. The other options are incorrect because they do not describe the functions of the myelin sheath.

Regeneration, sensory perception, and nutrition are not functions performed by the myelin sheath for a nerve cell.

When a muscle cell is stimulated by a nerve impulse, calcium ions are released from the sarcoplasmic reticulum into the cytoplasm. The calcium ions bind to the troponin complex, which is a protein that regulates the interaction between actin and myosin filaments. The binding of calcium to troponin causes a conformational change that exposes the binding sites for myosin on the actin filaments. This allows the myosin heads to attach to the actin and pull the filaments past each other, resulting in muscle contraction.

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. 100,000. 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 pH 4 solution has a hydrogen-ion concentration that is 10^5 (or 100,000) times greater than that of a pH 9 solution.

a. 0.00001 is the hydrogen-ion concentration of a pH 9 solution as compared with a pH 4 solution.

b. 5 is the difference in pH units between a pH 4 solution and a pH 9 solution.

d. 50 is not the correct answer.

The result of using a catalyst in a chemical reaction is that the reaction is completed in a shorter amount of time ¹. A catalyst is a chemical substance that affects the rate of a chemical reaction by altering the activation energy required for the reaction to proceed ¹. This process is called catalysis ¹. A catalyst provides an alternative pathway for the reaction, one that has a lower activation energy than the uncatalyzed pathway .

The other options are not correct because they do not accurately describe the result of using a catalyst in a chemical reaction. A more desirable product is not necessarily formed, a greater amount of heat energy is not necessarily released by the reaction, and the yield of product is not necessarily increased as a result of using a catalyst.

The correct answer is c. Lacteal vessels. Lipids absorbed in the small intestine will first enter lacteal vessels, which are small lymphatic vessels located in the villi of the small intestine. These vessels transport the absorbed lipids to the lymphatic system, where they eventually enter the bloodstream.

a. Veins and b. Arteries are blood vessels that transport blood throughout the body. Lipids absorbed in the small intestine do not directly enter these vessels.

d. Interstitial spaces are spaces between cells and tissues that contain interstitial fluid. Lipids absorbed in the small intestine do not directly enter these spaces.

Both digestion and absorption happen in the small intestine ¹. Digestion is the process by which food is broken down into small molecules that the body can absorb and use for energy, growth, and repair ¹. The final products of digestion are absorbed from the digestive tract, primarily in the small intestine ¹.

The other options are not correct because they do not accurately describe where both digestion and absorption happen in the digestive system. The gallbladder stores bile produced by the liver, but does not play a direct role in digestion or absorption. The esophagus transports food from the mouth to the stomach, but does not play a direct role in digestion or absorption. The stomach plays a role in digestion by churning food and mixing it with gastric juices, but most absorption occurs in the small intestine.

The correct answer is b. Spectrophotometer. A spectrophotometer is a tool that can be used to measure the turbidity of a liquid by measuring the transmission of light through the sample. Turbidity is a measure of the cloudiness or haziness of a liquid caused by the presence of suspended particles. A spectrophotometer measures the amount of light that passes through the sample and compares it to the amount of light that passes through a reference sample to determine the turbidity.

a. A centrifuge is a tool used to separate components of a mixture based on their densities, not to measure

turbidity.

c. A microdensitometer is a tool used to measure the optical density of an image, not to measure turbidity.

d. An electrophorometer is a tool used to separate charged particles based on their size and charge, not to measure turbidity.

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.

The doctor refuses to prescribe antibiotics to the patient because the illness is caused by a virus. The common cold is a viral infection of the upper respiratory tract. Antibiotics are not effective against viral infections and are only used to treat bacterial infections.

The other options are not correct because they do not accurately describe the cause of the common cold and sore throat. Fungus, protist, and bacteria are not the pathogens responsible for causing the common cold.