Q: Stirring, surface area, and temperature affect the rate at which what occurs? Read this paragraph and choose the correct option from the provided answers: When you add sugar to a cold drink, you may stir it to help the sugar dissolve. If you don't stir, the sugar may eventually dissolve, but it will take much longer. Stirring is one of several factors that affect how fast a solute dissolves in a solvent. Temperature is another factor. A solid solute dissolves faster at a higher temperature. For example, sugar dissolves faster in hot tea than in ice tea. A third factor that affects the rate of dissolving is the surface area of the solute. For example, if you put granulated sugar in a glass of ice tea, it will dissolve more quickly than the same amount of sugar in a cube. That's because granulated sugar has much more surface area than a cube of sugar. You can see videos of all three factors at these URLs:. Choices: - concentration dissolves - solute freezes - solute fragments - solute dissolves A:
solute dissolves

(Question)
Q: What model of the atom features an electron orbiting a nucleus, forming a closed-current loop and producing a magnetic field with a north pole and a south pole?. Read this paragraph and choose the correct option from the provided answers: Figure 22.13 (a) In the planetary model of the atom, an electron orbits a nucleus, forming a closed-current loop and producing a magnetic field with a north pole and a south pole. (b) Electrons have spin and can be crudely pictured as rotating charge, forming a current that produces a magnetic field with a north pole and a south pole. Neither the planetary model nor the image of a spinning electron is completely consistent with modern physics. However, they do provide a useful way of understanding phenomena. Choices: - hydrogen model - solar model - gravitational model - planetary model A:
(Answer)
planetary model

Ques: Q: What is the term for the hard covering that protects insects, crustaceans, and spiders? Read this paragraph and choose the correct option from the provided answers: Most animals have an exoskeleton, including insects, spiders, scorpions, horseshoe crabs, centipedes, and crustaceans. Scientists estimate that, of insects alone, there are over 30 million species on our planet. The exoskeleton is a hard covering or shell that provides benefits to the animal, such as protection against damage from predators and from water loss (for land animals); it also provides for the attachments of muscles. As the tough and resistant outer cover of an arthropod, the exoskeleton may be constructed of a tough polymer such as chitin and is often biomineralized with materials such as calcium carbonate. This is fused to the animal's epidermis. Ingrowths of the exoskeleton, called apodemes, function as attachment sites for muscles, similar to tendons in more advanced animals (Figure 33.3). In order to grow, the animal must first synthesize a new exoskeleton underneath the old one and then shed or molt the original covering. This limits the animal's ability to grow continually, and may limit the individual's ability to mature if molting does not occur at the proper time. The thickness of the exoskeleton must be increased significantly to accommodate any increase in weight. It is estimated that a doubling of body size increases body weight by a factor of eight. The increasing thickness of the chitin necessary to support this weight limits most animals with an exoskeleton to a relatively small size. The same principles apply to endoskeletons, but they are more efficient because muscles are attached on the outside, making it easier to compensate for increased mass. Choices: - endoplate - endoskeleton - exoplate - exoskeleton A:
Ans: exoskeleton

(Q).
Q: Constriction and dilation allow the circulatory system to change the amount of blood flowing to which body parts? Read this paragraph and choose the correct option from the provided answers: Constriction and dilation allow the circulatory system to change the amount of blood flowing to different organs. For example, during a fight-or-flight response, dilation and constriction of blood vessels allow more blood to flow to skeletal muscles and less to flow to digestive organs. Dilation of blood vessels in the skin allows more blood to flow to the body surface so the body can lose heat. Constriction of these blood vessels has the opposite effect and helps conserve body heat. Choices: - arteries - tissues - muscles - organs A:
(A).
organs

Ques:Q: How do amphibians reproduce? Read this paragraph and choose the correct option from the provided answers: Amphibians reproduce sexually. Fertilization may take place inside or outside the body. Amphibians are oviparous. Embryos develop in eggs outside the mother's body. Choices: - asexually - biologically - they don't - sexually A:

Ans:sexually

Q: Bacterial dna is contained in one circular chromosome, located where? Read this paragraph and choose the correct option from the provided answers: Bacteria lack many of the structures that eukaryotic cells contain. For example, they don't have a nucleus. They also lack membrane-bound organelles, such as mitochondria or chloroplasts. The DNA of a bacterial cell is also different from a eukaryotic cell. Bacterial DNA is contained in one circular chromosome, located in the cytoplasm. Eukaryotes have several linear chromosomes. Bacteria also have two additional unique features: a cell wall and flagella. Choices: - neuron - mucus - cerebellum - cytoplasm A:
cytoplasm