how is the density of a substance calculated

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. How is the density of a substance calculated?

A. Mass / Volume
B. Volume / Mass
C. Mass x Volume
D. None of the above

Correct answer: A

Rationale: The density of a substance is calculated by dividing the mass of the substance by its volume. The formula for density is Density = Mass / Volume. This calculation allows us to determine how much mass is present in a given volume of a substance, making option A the correct choice. Choice B (Volume / Mass) is incorrect because density is defined as mass per unit volume, so mass should be the numerator. Choice C (Mass x Volume) is incorrect as this would result in a different unit of measurement and not represent density. Choice D (None of the above) is incorrect as there is a specific formula for calculating density, which is mass divided by volume.

2. What is the product of translation from an RNA template?

A. DNA
B. Lipid
C. Polypeptide
D. Carbohydrate

Correct answer: C

Rationale: Translation is the process by which the genetic information carried by mRNA is decoded to synthesize a polypeptide chain. This essential process occurs at the ribosomes within the cell. The product of translation from an RNA template is a polypeptide, not DNA, lipid, or carbohydrate. DNA is involved in transcription, lipids are not directly produced in translation, and carbohydrates are not synthesized through translation. Therefore, the correct product resulting from translation from an RNA template is a polypeptide, making choice C, 'Polypeptide,' the correct answer.

3. DNA has both a 'sense' and 'antisense' strand. What is true about the antisense strand?

A. It runs 5' to 3'.
B. It runs 3' to 5'.
C. It is used in replication.
D. It is the direction in which DNA is stored.

Correct answer: B

Rationale: The correct answer is B. The antisense strand runs 3' to 5', which is opposite to the direction of the sense strand. It serves as the template strand for transcription, where an RNA molecule is synthesized complementary to the antisense strand. Choice A is incorrect because the antisense strand runs in the opposite direction. Choice C is incorrect as the antisense strand is primarily involved in transcription, not replication. Choice D is incorrect as the direction of DNA storage is not determined by the antisense strand.

4. What is a monohybrid cross, and what is the ratio of dominant to recessive gene manifestation?

A. A cross involving two traits, 9:3:3:1
B. A cross involving one trait, 3:1
C. A cross involving two traits, 1:2:1
D. A cross involving one trait, 1:1

Correct answer: B

Rationale: A monohybrid cross is a genetic cross involving one trait. The ratio of dominant to recessive gene manifestation in the offspring is typically 3:1 when both parents are heterozygous. This ratio is the genotypic ratio, not just the phenotype ratio, where the dominant allele is present in 3 out of 4 offspring, and the recessive allele is present in 1 out of 4 offspring. Choice A is incorrect because it describes a dihybrid cross ratio. Choice C is incorrect as it represents the genotypic ratio for a monohybrid cross involving incomplete dominance. Choice D is incorrect as it does not reflect the typical ratio for a monohybrid cross.

5. What are the building blocks of proteins?

A. Sugars
B. Fatty acids
C. Amino acids
D. Nucleotides

Correct answer: C

Rationale: Proteins are macromolecules made up of long chains of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to carry out various functions in the body. Sugars (choice A) are the building blocks of carbohydrates, fatty acids (choice B) are the building blocks of lipids, and nucleotides (choice D) are the building blocks of nucleic acids like DNA and RNA. Therefore, the correct answer is amino acids (choice C), as they are specifically responsible for protein synthesis.