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. Skeletal muscles are not autorhythmic; this term refers to the ability to generate a rhythmical electrical impulse without the need for nervous stimulation, which is a characteristic of cardiac muscles.

B. Cardiac muscles contain intercalated discs, which are unique structural formations that allow for the rapid transmission of electrical impulses between cardiac cells. This feature is not found in skeletal muscles, which are composed of individual muscle fibers that are controlled voluntarily.

C. Cardiac muscles are involuntary, meaning they function without conscious control, which is necessary for the continuous pumping action of the heart. In contrast, skeletal muscles are under voluntary control, allowing for movement of the body in response to conscious decisions.

D. Skeletal muscles are not found in the viscera; they are attached to bones and are responsible for body movements. Cardiac muscles, on the other hand, are located in the heart, which is not in the cranium but in the thoracic cavity. The term 'viscera' refers to the internal organs in the main cavities of the body, especially those in the abdomen, not the cranium.

A. This option changes the population, which could introduce new variables related to gender differences in metabolism or physical performance.

B. This option introduces another variable by using two different energy drinks, which could have different ingredients and effects.

C. This option changes the distance run, which could affect the endurance aspect rather than the speed.

D. To best support the conclusion that energy drinks increase the speed of running in women, it would be most effective to conduct a controlled experiment where a variable is changed while others are kept constant. By giving half of the women water and the other half the energy drink, researchers can directly compare the effects of the energy drink against a baseline (water), which has no enhancing properties on running speed. This comparison would help to isolate the effect of the energy drink on running performance

A. Methane molecule (CH4) consists of one carbon atom forming four covalent bonds with four hydrogen atoms.

B. Ammonia molecule (NH3) involves one nitrogen atom forming three covalent bonds with three hydrogen atoms.

C. Chlorine molecule (Cl2) is made up of two chlorine atoms sharing a single covalent bond between them.

D. Water molecule (H2O) has one oxygen atom forming two covalent bonds with two hydrogen atoms.

A. When water dissolves sugar, it is a physical change rather than a chemical reaction. The water molecules surround the sugar molecules and allow them to disperse throughout the solution, but the chemical structure of neither the water nor the sugar changes.

B. When water reacts with sodium metal, it is indeed a chemical reaction. This reaction is quite vigorous and exothermic, producing hydrogen gas and sodium hydroxide. The reaction can be represented by the chemical equation 2Na + 2H2O 2NaOH + H2. This is a classic example of a single displacement reaction where the metal takes the place of hydrogen in water.

C. Boiling water to produce steam at 100° C (212° F) is a physical change. Here, the water is changing its state from liquid to gas due to the input of heat. However, the molecular structure of water H2O remains the same before and after boiling.

D. The separation of water and oil when combined is also a physical process. This occurs because water is polar, meaning it has a slight charge difference across its molecule, while oil is non-polar and does not mix with water. This difference in polarity leads to the formation of separate layers, with oil typically floating on top of the water due to its lower density, but no chemical reaction occurs between the two substances.

A. Both endocrine and exocrine glands produce secretions that affect target cells, but the way they deliver these secretions to the target cells is different. Endocrine glands release hormones directly into the bloodstream, which then travel to the target cells, while exocrine glands secrete their products into ducts that lead directly to the target areas.

B. Nerve innervation refers to the supply of nerves to a particular part of the body or organ.

While nerve innervation can influence the activity of glands, it is not the primary distinguishing feature between endocrine and exocrine glands.

C. The biochemical nature of the secretions can vary widely among different glands, but this is not the main characteristic that differentiates endocrine from exocrine glands. Both can produce a variety of biochemical substances, including enzymes, hormones, and other compounds.

D. This is the key difference between endocrine and exocrine glands. Endocrine glands are ductless and release their hormones directly into the bloodstream, allowing them to be transported throughout the body. In contrast, exocrine glands have ducts through which they release their secretions to the surface of an organ or tissue, or to the outside of the body.

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. Monosaccharides are the simplest form of carbohydrates and serve as the building blocks for more complex carbohydrates but are not considered macromolecules.

B. Proteins are large, complex molecules that play many critical roles in the body. They are required for the structure, function, and regulation of the body's tissues and organs. Proteins are made up of one or more long chains of amino acids, which are the building blocks of proteins. This makes them biological macromolecules.

C. Amino acids are organic compounds that combine to form proteins. They are the basic building blocks of proteins but are not macromolecules themselves.

D. Nucleic acids, such as DNA and RNA, are biopolymers essential to all known forms of life. They are macromolecules because they are composed of thousands of smaller units called nucleotides, but in this context, proteins are the more fitting example of a biological macromolecule.

A. The rate of fall is affected by mass of the object, since object D and C fall at a faster rate than A. However it is important to consider other factors such as shape and size of the object.

B. Although objects A and B have the same mass, they do not fall at the same rate, as evidenced by their different times of fall.

C. The data does not support the conclusion that greater mass leads to a faster fall. Object C, with a mass of 30.0g, falls in 0.5sec, while object D, with a greater mass of 35.0g, falls in a longer time of 1.5sec.

D. A and B have the same mass but have different rates of fall. This indicates that air resistance is greater for A, hence the slower rate of fall.

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.

A. 5’ TCGUTCGCU 3’: This sequence is incorrect because it contains 'U', which is a base found in RNA, not DNA. DNA contains the base 'T' for thymine, not 'U' for uracil.

B. 5’ UCGAUCGCA 3’: This option is also incorrect for the same reason as option A; it includes 'U', indicating it is an RNA sequence, not a DNA sequence.

C. 3’ AGCTAGCGT 5’: This sequence is simply the original strand read in the opposite direction, not the complementary strand.

D. 3’ TCGATCGCA 5’: This is the correct complementary DNA sequence. In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). Therefore, for the original DNA sequence 5' AGCTAGCGT 3', the complementary strand must read 3' TCGATCGCA 5', with each base pairing correctly according to the rules of base pairing in DNA. This sequence is antiparallel to the original, as indicated by the 3' and 5' ends, which is a key characteristic of DNA structure.