To separate genomic DNA fragments by size, which of these laboratory methods is most useful?

A. Filtration

B. Spectrophotometry

C. Titration

D. Electrophoresis

Answer Explanation:

One of the most common techniques for separating DNA fragments by size is electrophoresis. Electrophoresis is a process that uses an electric field to move charged molecules through a porous gel matrix. The gel acts as a sieve, allowing smaller molecules to move faster and farther than larger ones. By applying a dye to the DNA samples and loading them into wells at one end of the gel, the DNA fragments can be visualized as bands after electrophoresis. The distance of each band from the well indicates the size of the corresponding DNA fragment.

Therefore, the Correct Answer is D.

Q #1: Testosterone is categorized as which of the following types of hormones?

A. Progestin

B. Androgen

C. Aldosterone

D. Estrogen

Answer Explanation

Testosterone is a hormone that belongs to the class of androgens, which are responsible for the development and maintenance of male characteristics. Androgens are synthesized from cholesterol and can be converted into other types of hormones, such as estrogens and progestins. Aldosterone is a different type of hormone that regulates the balance of salt and water in the body.
Q #2: In the following data table of an experiment carried out at 4° C (39.2° F) over 4 hours, which of the following options represents the dependent variable? Solution in bag Solution outside bag Bag mass change (g) water water   -0.2 20% sucrose   water   +2.4   40% sucrose   water   +4.3   60% sucrose   water   +5.8  

A. Duration

B. Temperature

C. Sucrose concentrations

D. Bag mass change

Answer Explanation

The dependent variable is the variable that is measured or observed in an experiment. It is the variable that changes as a result of the independent variable, which is the variable that is manipulated or controlled by the experimenter. In this case, the dependent variable is the bag mass change, because it depends on the sucrose concentrations in the bag and outside the bag. The other variables, such as duration, temperature, and sucrose concentrations, are independent variables that are set by the experimenter.
Q #3: Which of the following glands synthesizes antidiuretic hormone?

A. Pancreas

B. Pineal gland

C. Hypothalamus

D. Thymus

Answer Explanation

Antidiuretic hormone (ADH) is a peptide hormone that regulates the water balance in the body by increasing the reabsorption of water by the kidneys. ADH is synthesized by the hypothalamus, a part of the brain that controls many functions, such as appetite, sleep, and body temperature. ADH is then stored and released by the posterior pituitary gland, which is located at the base of the brain.

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To separate genomic DNA fragments by size, which of these laboratory methods is most useful?

More Questions on TEAS 7 Science

Q #1: Testosterone is categorized as which of the following types of hormones?

Answer Explanation

Answer Explanation

Q #3: Which of the following glands synthesizes antidiuretic hormone?

Answer Explanation

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