ap bio unit 1 A

30% adenine in RNA strand. how much thymine?

0 percent

A feature of organic compounds NOT found in inorganic compounds is the presence of

Carbon atoms covalently bonded to each other

A researcher measured the temperature at which two different samples of double-stranded DNA denature (separate into single strands). Sample 1 denatured at a significantly lower temperature than sample 2 did. Based on the data, the researcher claims that the DNA in sample 2is composed of a higher percentage of guanine and cytosine than the DNA in sample 1 is.Which of the following best supports the researcher's claim?

Guanine-cytosine pairs denature at a higher temperature because they have more hydrogen bonds between them than adenine-thymine pairs do.

Which of the following is responsible for the cohesive property of water?

Hydrogen bonds form between the oxygen atom of one water molecule and a hydrogen atom of another water molecule

A typical bag of fertilizer contains high levels of nitrogen, phosphorus, and potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area?

Nitrogen will be incorporated into nucleic acids.

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ?

Nucleic acid #1 contains adenine-thymine base pairs, whereas nucleic acid #2 does not.

which of the following statements best describes how organisms how organisims such as rabbits obtain the carbon necessary for building biological molecules?

Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules

Which of the following best describes the hydrolysis of carbohydrates?

The addition of water molecule breaks a covalent bond between sugar monomers

Figure 1 represents a common process that occurs in organisms.Figure 1. Structural formula for a common biological reactionWhich of the following is an accurate description of the process shown in Figure 1 ?

The formation of a covalent peptide bond in a dehydration synthesis reaction

Humans produce sweat as a cooling mechanismto maintain a stable internal temperature. Whichof the following best explains how the propertiesof water contribute to this physiological process?

The high heat of vaporization of waterallows the body to remove excess heatthrough a phase change of water fromliquid to gas

Which of the following best describes how amino acids affect the tertiary structure of a protein?

The interactions of the different R -groups with other R -groups and with their environment determine the tertiary structure of the protein.

Water and ammonia interact to form hydrogen bonds, as represented in the figure. Which statement best helps explain the formation of the hydrogen bond represented in the figure?

The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

A mutation in the gene coding for a single-polypeptide enzyme results in the substitution of the amino acid serine, which has a polar R group, by the amino acid phenylalanine, which has a nonpolar R group. When researchers test the catalysis of the normal enzyme and the mutated enzyme, they find that the mutated enzyme has much lower activity than the normal enzyme does.

The substitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does.

The diagram shows how water can adhere to the xylem in the stems of plants, which contributes to water movement in the plant. Which of the following best explains how water is able to move upward from the roots of a plant, through its xylem in the stem, and out to the leaves?

Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and with the walls of the xylem.

what carries genetic code

nucleic acids

which of the following best describes the structures of carbohydrates?

they occur as monomers, chains of monomers, and branched structures