To separate genomic DNA fragments by size, which of these laboratory methods is most useful?
A. Titration
B. Electrophoresis
C. Filtration
D. Spectrophotometry
Electrophoresis is the most useful laboratory method for separating genomic DNA fragments by size.
Electrophoresis is a technique that uses an electric field to separate charged molecules, such as DNA fragments, based on their size and charge.
Choice A is not correct because titration is a laboratory method used to determine the concentration of a solution.
Choice C is not correct because filtration is a laboratory method used to separate solids from liquids.
Choice D is not correct because spectrophotometry is a laboratory method used to measure the absorbance of light by a solution.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: Which of the following structures is present in both prokaryotic and eukaryotic cells?
A. Cell membrane
B. Golgi apparatus
C. Chloroplasts
D. Endoplasmic reticulum
Answer Explanation
The cell membrane is present in both prokaryotic and eukaryotic cells.
The cell membrane is a thin, flexible barrier that surrounds all cells and separates the inside of the cell from the outside environment.
It is composed of a lipid bilayer and regulates the movement of substances into and out of the cell.
Choice B is incorrect because the Golgi apparatus is not present in prokaryotic cells.
The Golgi apparatus is an organelle found in eukaryotic cells that is involved in modifying, sorting, and packaging proteins and lipids for transport to other parts of the cell or to be secreted outside the cell.
Choice C is incorrect because chloroplasts are not present in prokaryotic cells.
Chloroplasts are organelles found in plant cells and some algae that are responsible for photosynthesis.
Choice D is incorrect because the endoplasmic reticulum is not present in prokaryotic cells.
The endoplasmic reticulum is an organelle found in eukaryotic cells that is involved in protein synthesis and lipid metabolism.
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Q #2: A myocardial infarction affects which of the following blood vessels of the heart?
A. Coronary
B. Aorta
C. Pulmonary
D. Vena cava
Answer Explanation
A myocardial infarction affects the coronary blood vessels of the heart.
A myocardial infarction, commonly known as a heart attack, occurs when blood flow decreases or stops in the coronary artery of the heart, causing damage to the heart muscle 1.
Choice B is incorrect because the aorta is not a blood vessel of the heart.
The aorta is the main artery that carries oxygenated blood from the heart to the rest of the body.
Choice C is incorrect because the pulmonary blood vessels are not affected by a myocardial infarction.
The pulmonary blood vessels carry deoxygenated blood from the heart to the lungs.
Choice D is incorrect because the vena cava is not a blood vessel of the heart.
The vena cava is a large vein that carries deoxygenated blood from the body to the heart.
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Q #3: Which of the following vessels carries oxygenated blood?
A. Superior vena cava
B. Inferior vena cava.
C. Pulmonary artery
D. Pulmonary vein
Answer Explanation
The pulmonary veins are the vessels that carry oxygenated blood from the lungs to the left atrium of the heart.
Choice A is not correct because the superior vena cava carries deoxygenated blood from the upper body to the right atrium of the heart.
Choice B is not correct because the inferior vena cava carries deoxygenated blood from the lower body to the right atrium of the heart.
Choice C is not correct because the pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs.
