Q: In scientific investigations, descriptive statistics are useful for summarizing the characteristics of large what? Read this paragraph and choose the correct option from the provided answers: The girls in the picture above make up a small samplethere are only four of them. In scientific investigations, samples may include hundreds or even thousands of people or other objects of study. Especially when samples are very large, it's important to be able to summarize their overall characteristics with a few numbers. That's where descriptive statistics come in. Descriptive statistics are measures that show the central tendency, or center, of a sample or the variation in a sample. Choices: - organisms - questions - tissues - samples A:
samples

(Question)
Q: Shark teeth likely evolved from the jagged scales that cover their skin, called what? Read this paragraph and choose the correct option from the provided answers: Chondrichthyes: Cartilaginous Fishes The clade Chondrichthyes is diverse, consisting of sharks (Figure 29.11), rays, and skates, together with sawfishes and a few dozen species of fishes called chimaeras, or "ghost" sharks. " Chondrichthyes are jawed fishes that possess paired fins and a skeleton made of cartilage. This clade arose approximately 370 million years ago in the early or middle Devonian. They are thought to be descended from the placoderms, which had skeletons made of bone; thus, the cartilaginous skeleton of Chondrichthyes is a later development. Parts of shark skeleton are strengthened by granules of calcium carbonate, but this is not the same as bone. Most cartilaginous fishes live in marine habitats, with a few species living in fresh water for a part or all of their lives. Most sharks are carnivores that feed on live prey, either swallowing it whole or using their jaws and teeth to tear it into smaller pieces. Shark teeth likely evolved from the jagged scales that cover their skin, called placoid scales. Some species of sharks and rays are suspension feeders that feed on plankton. Choices: - heterotroph scales - hook scales - pinworm scales - placoid scales A:
(Answer)
placoid scales

Ques: Q: Nuclear reactors use fission reactions to vaporize water, producing steam to drive a turbine and generate what? Read this paragraph and choose the correct option from the provided answers: Nuclear reactors use fission reactions to vaporize water. The resulting steam is used to drive a turbine, which generates electricity. Choices: - light - oil - fuel - electricity A:
Ans: electricity

(Q).
Q: What happens to an animal's telomeres as it ages? Read this paragraph and choose the correct option from the provided answers: As cells divide, their chromosomes get shorter. This is because the telomeres, the DNA sequences at both ends of a chromosome, lose material every time the DNA is replicated. The older the animal is, the shorter its telomeres will be, because of the number of cell cycles the cells have been through This is a natural part of aging. So, what happens to the clone if its transferred nucleus is already fairly old? Will the shortened telomeres affect its development or lifespan? The answer is still unclear. But starting a new organisms with "old" DNA with shortened telomeres is bound to have some effects, at least in some clones. Some cloned animals may be affected, others may not. Dolly the sheep's chromosomes did have shorter telomere lengths than normal. This means that Dolly's cells were aging faster than the cells from a normal sheep. Choices: - divide - lengthen - multiply - shorten A:
(A).
shorten

Ques:Q: The product of a wave's wavelength and its frequency is what? Read this paragraph and choose the correct option from the provided answers: The product of a wave's wavelength () and its frequency (), , is the speed of the wave. Thus, for electromagnetic radiation in a vacuum: c = 2.998 10 8 ms 1 = Wavelength and frequency are inversely proportional: As the wavelength increases, the frequency decreases. The inverse proportionality is illustrated in Figure 6.3. This figure also shows the electromagnetic spectrum, the range of all types of electromagnetic radiation. Each of the various colors of visible light has specific frequencies and wavelengths associated with them, and you can see that visible light makes up only a small portion of the electromagnetic spectrum. Because the technologies developed to work in various parts of the electromagnetic spectrum are different, for reasons of convenience and historical legacies, different units are typically used for different parts of the spectrum. For example, radio waves are usually specified as frequencies (typically in units of MHz), while the visible region is usually specified in wavelengths (typically in units of nm or angstroms). Choices: - trough - velocity - amplitude - speed A:

Ans:speed

Q: Nonmetal structures contain what type of bonds? Read this paragraph and choose the correct option from the provided answers: Structures of the Nonmetals The structures of the nonmetals differ dramatically from those of metals. Metals crystallize in closely packed arrays that do not contain molecules or covalent bonds. Nonmetal structures contain covalent bonds, and many nonmetals consist of individual molecules. The electrons in nonmetals are localized in covalent bonds, whereas in a metal, there is delocalization of the electrons throughout the solid. The noble gases are all monatomic, whereas the other nonmetal gaseshydrogen, nitrogen, oxygen, fluorine, and chlorinenormally exist as the diatomic molecules H2, N2, O2, F2, and Cl2. The other halogens are also diatomic; Br2 is a liquid and I2 exists as a solid under normal conditions. The changes in state as one moves down the halogen family offer excellent examples of the increasing strength of intermolecular London forces with increasing molecular mass and increasing polarizability. Oxygen has two allotropes: O2, dioxygen, and O3, ozone. Phosphorus has three common allotropes, commonly referred to by their colors: white, red, and black. Sulfur has several allotropes. There are also many carbon allotropes. Most people know of diamond, graphite, and charcoal, but fewer people know of the recent discovery of fullerenes, carbon nanotubes, and graphene. Descriptions of the physical properties of three nonmetals that are characteristic of molecular solids follow. Choices: - prevalent - polymeric - gravitational - covalent A:
covalent