If a portion of a strand of DNA bases reads 3’TCGATCGCA 5’, what would the sequence of bases on the complementary strand read?
A. 5’AGCTAGCGT 3’
B. 3’ TCGUTCGCU 5’
C. 3’ AGCTAGCGT 5’
D. 5’ GGUTACTAC 3’
The sequence of bases on the complementary strand of DNA would read 5’AGCTAGCGT 3’ (Choice A). In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The complementary strand is also antiparallel to the original strand, meaning that it runs in the opposite direction with the 5' end matching up with the 3' end of the original strand.
The other options do not accurately represent the complementary sequence of bases or the antiparallel orientation of the strands.
BONUS:
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: For which of the following reasons does a chloride ion have a negative charge?
A. It gained an electron
B. It lost an electron.
C. It lost a proton.
D. It gained a proton.
Answer Explanation
A chloride ion has a negative charge because it gained an electron. When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons. In the case of a chloride ion, the neutral chlorine atom gains an electron to become a negatively charged chloride ion.
The other options are incorrect because they do not result in a negative charge. Losing an electron would result in a positive charge. Losing or gaining a proton would change the identity of the atom and is not related to the formation of a chloride ion.
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Q #2: Which of the following functions does the myelin sheath perform for a nerve cell?
A. Insulation
B. Regeneration
C. Sensory perception
D. Nutrition
Answer Explanation
The myelin sheath is a protective membrane that wraps around parts of certain nerve cells.
Its fatty-protein coating provides protective insulation for your nerve cell like the plastic insulation covering that encases the wires of an electrical cord ².
This allows the electrical impulses to travel quickly and efficiently between one nerve cell and the next. The other options are incorrect because they do not describe the functions of the myelin sheath.
Regeneration, sensory perception, and nutrition are not functions performed by the myelin sheath for a nerve cell.
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Q #3: Which of the following substances is excreted by sweat glands in response to the breakdown of proteins and the formation of ammonia?
A. Lysozymes
B. Urea
C. Water
D. Sebum
Answer Explanation
Urea is a waste product that is formed when proteins are broken down in the body. It is excreted by the kidneys in urine, but small amounts can also be excreted by sweat glands in sweat.
The other options are not substances that are excreted by sweat glands in response to the breakdown of proteins and the formation of ammonia. Lysozymes are enzymes that break down bacterial cell walls, water is a component of sweat but is not specifically related to protein breakdown, and sebum is an oily substance produced by sebaceous glands to lubricate the skin.
