Ques:Q: Many objects have color because they contain what? Read this paragraph and choose the correct option from the provided answers: Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow. Choices: - solvents - vitamins - salts - pigments A:

Ans:pigments
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Ques:Q: Pacemaker cells stimulate the spontaneous contraction of cardiac muscle as a functional unit, called a what? Read this paragraph and choose the correct option from the provided answers: 10.7 Cardiac Muscle Tissue Cardiac muscle is striated muscle that is present only in the heart. Cardiac muscle fibers have a single nucleus, are branched, and joined to one another by intercalated discs that contain gap junctions for depolarization between cells and desmosomes to hold the fibers together when the heart contracts. Contraction in each cardiac muscle fiber is triggered by Ca++ ions in a similar manner as skeletal muscle, but here the Ca++ ions come from SR and through voltage-gated calcium channels in the sarcolemma. Pacemaker cells stimulate the spontaneous contraction of cardiac muscle as a functional unit, called a syncytium. Choices: - coenocyte - tapetum - adipocytes - syncytium A:

Ans:syncytium
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Ques:Q: How much space a surface covers is known as what? Read this paragraph and choose the correct option from the provided answers: The area of a surface is how much space it covers. It's easy to calculate the area of a surface if it has a regular shape, such as the blue rectangle in the sketch below. You simply substitute measurements of the surface into the correct formula. To find the area of a rectangular surface, use this formula:. Choices: - Flatness - Lenght - Height - area A:

Ans:area
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Ques:Q: What do you call compounds whose properties are different because their atoms are bonded together in different arrangements? Read this paragraph and choose the correct option from the provided answers: Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH 4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydrocarbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers . Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. Choices: - isotopes - mixtures - ionic compounds - isomers A:

Ans:
isomers
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