Use the table below to answer the question.

Object	Mass	Time of Fall
A	5.0g	2.0sec
B	5.0g	1.0sec
C	30.0g	0.5sec

D

35.0g

1.5sec

Which of the following conclusions is supported by the data?

A. A substance with a pH of 3 is not more alkaline but more acidic than a substance with a pH of 4. The pH scale measures how acidic or basic a substance is, with lower numbers being more acidic and higher numbers being more alkaline.

B. A substance with a pH of 3 is indeed 10 times more acidic than a substance with a pH of 4.

The pH scale is logarithmic, meaning each whole pH value below 7 is ten times more acidic than the next higher value.

C. A substance with a pH of 3 is not more alkaline but more acidic than a substance with a pH of 4, and the difference is not two times but ten times in terms of hydrogen ion concentration.

D. While a substance with a pH of 3 is more acidic than a substance with a pH of 4, the scale is logarithmic, so it is not simply two times more acidic, but ten times more acidic.

A. Uracil is a nucleotide that is unique to RNA. It is one of the four nitrogenous bases found in RNA molecules and replaces thymine, which is found in DNA. In RNA, uracil binds with adenine during the formation of RNA strands. Its structure is similar to that of thymine, but it lacks a methyl group on the carbon at position 5.

B. Thymine, on the other hand, is found only in DNA. It is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. Thymine is the DNA counterpart of uracil and pairs with adenine through two hydrogen bonds. In the DNA double helix, thymine helps to stabilize the nucleic acid structures with its pairing with adenine.

C. Guanine is a nucleotide that is found in both DNA and RNA. It is one of the five standard nucleobases and pairs with cytosine with three hydrogen bonds. Guanine is essential for the structure of both DNA and RNA due to its complementary pairing, which helps to maintain the integrity of the genetic information.

D. Adenine is also a nucleotide present in both DNA and RNA. It is one of the two purine nucleobases used in forming nucleotides of the nucleic acids. In DNA, adenine binds to thymine with two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, adenine binds to uracil instead.

A. The kidneys are a pair of bean-shaped organs located in the posterior part of the abdomen.

They are primarily responsible for filtering blood, removing waste products, and excess substances through the urine. The kidneys maintain overall fluid balance, regulate and filter minerals from blood, and create hormones that help produce red blood cells, promote bone health, and regulate blood pressure.

B. The liver, while it does process nitrogenous waste, its primary role is to detoxify chemicals and metabolize drugs. The liver secretes bile that ends up back in the intestines and also makes proteins important for blood clotting and other functions.

C. The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in the digestion of fats. It does not remove nitrogenous waste from the body.

D. The large intestine absorbs water and salts from the material that has not been digested as food, and is passed from the small intestine. It also stores waste products until they're excreted. It is not directly involved in the removal of nitrogenous waste.

A. Plasma cells are specialized white blood cells that produce antibodies, which are proteins that can bind to and help neutralize pathogens like bacteria and viruses.

B. Helper T-cells play a crucial role in the immune system by activating and directing other immune cells, including B-cells to produce antibodies and cytotoxic T-cells to kill infected cells. They recognize foreign antigens presented by antigen-presenting cells and release cytokines that stimulate the immune response.

C. Cytotoxic T-cells, also known as killer T-cells, directly attack and destroy cells that have been infected by viruses or have become cancerous. They are part of the adaptive immune response and are important for eliminating intracellular pathogens.

D. Natural killer cells are a type of lymphocyte that can kill virus-infected cells and tumor cells without prior sensitization to them. They are part of the innate immune system and provide a rapid response to virally infected cells and a degree of immune memory.

A. The rectum is the final section of the large intestine, terminating at the anus. It functions as a temporary storage site for feces before they are expelled from the body.

B. The jejunum is the second part of the small intestine, located between the duodenum and the ileum. It is specialized for the absorption of nutrients during digestion.

C. The cecum is a pouch connected to the junction of the small and large intestines. The vermiform appendix extends from the cecum, and although its function in humans is not entirely clear, it is believed to play a role in the immune system.

D. The ischium is not part of the digestive system; it is one of the three bones that make up the pelvis. It is important for sitting and is connected to the lower limbs.

A. The cervical canal is the narrow passage through the cervix, connecting the vagina to the uterus. It is not typically the site of fertilization but rather serves as a gateway for sperm to enter the uterus and subsequently the Fallopian tubes where fertilization can occur.

B. The ovary is the female reproductive organ that produces eggs, or ova. While it is crucial for providing the egg, it is not the location where fertilization takes place.

C. The Fallopian tube, also known as the uterine tube or oviduct, is the site where fertilization usually occurs. After ovulation, the egg is captured by the fimbriae at the end of the Fallopian tube and is transported towards the uterus. If sperm are present in the Fallopian tube, fertilization can occur here.

D. The uterus is the muscular organ where the fertilized egg implants and develops into a fetus. However, it is not the typical site of fertilization; this process usually occurs in the Fallopian tubes before the zygote travels to the uterus for implantation.

A. The nucleus is the command center of a eukaryotic cell, containing most of the cell's genetic material and regulating gene expression to control cell growth, division, and differentiation.

B. Lysosomes are membrane-bound organelles that contain enzymes for digesting macromolecules, old cell parts, and foreign invaders, acting as the waste disposal system of the cell.

C. Mitochondria are known as the powerhouses of the cell. They are responsible for producing adenosine triphosphate (ATP), the cell's main energy-carrying molecule, through a process called cellular respiration.

D. Centrioles are cylindrical structures that are involved in the organization of microtubules during cell division, playing a crucial role in the formation of the spindle fibers that separate chromosomes during mitosis and meiosis.

A. Identifying routes for future climbs is a valid reason for an expedition, but it does not directly address the historical context of the 1924 expedition.

B. Measuring oxygen levels at high elevations is a scientific endeavor that can be conducted without the specific context of replicating an earlier climb.

C. By taking the same route, in the same season, and with similar materials and equipment as the 1924 expedition, the mountaineer is likely attempting to understand the variables and challenges faced by the original team, which could provide insights into the reasons behind the failure of that expedition.

D. Demonstrating the efficacy of modern technology in making climbing safer is a plausible objective, but it does not require the replication of the conditions of the 1924 expedition. Modern expeditions typically use current technology and techniques to enhance safety, rather than deliberately using outdated methods.

A. Melanocytes are specialized cells located in the basal layer of the epidermis. They are responsible for producing melanin, the pigment that gives skin its color. Melanocytes transfer pigment granules to adjacent keratinocytes, which then distribute the pigment throughout the epidermis, providing protection against ultraviolet radiation.

B. Keratinocytes are the most prevalent cell type in the epidermis, the outermost layer of the skin. While they receive pigment granules from melanocytes, they do not transfer them; instead, they integrate the pigment into their own structure, contributing to skin color and protection.

C. Langerhans cells are a type of dendritic cell found in the epidermis. They are part of the immune system and are involved in the body's defense mechanisms. They do not participate in the transfer of pigment granules.

D. Merkel cells are sensory cells located in the basal layer of the epidermis. They are associated with nerve endings and are involved in the sensation of touch. Merkel cells are not involved in the transfer of pigment granules to other cells.

A. The browning of an apple slice is caused by the enzyme polyphenol oxidase, which is present in the apple, not the lemon juice.

B. This acidic environment can denature the polyphenol oxidase enzyme in the apple, rendering it inactive and thus preventing the browning reaction.

C. The browning is a result of a chemical reaction, and dilution would not prevent the reaction from occurring.

D. The browning is due to the formation of melanin, which are pigments resulting from the enzymatic reaction. Lemon juice's acidity affects the enzyme responsible for this reaction, not the pigments themselves.