A nurse is reviewing the results of a patient’s DNA sequencing test, which was performed to diagnose a genetic disorder. The nurse notices that the patient has a mutation in one of the bases of the DNA. Which of the following is the correct term for this type of mutation?
A. Deletion
B. Insertion
C. Substitution
D. Inversion
The correct answer is choice C. Substitution.
A substitution mutation is a type of point mutation where one base in the DNA sequence is replaced by another base.
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Choice A is incorrect because a deletion mutation occurs when one or more bases are removed from the DNA sequence.
Choice B is incorrect because an insertion mutation occurs when one or more bases are added to the DNA sequence.
Choice D is incorrect because an inversion mutation occurs when a segment of DNA is reversed within the chromosome.
Therefore, the Correct Answer is C.
More Questions on TEAS 7 Science
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Q #1: Which of the following allows a limited range of immune cells to detect and respond rapidly to a wide range of pathogens that share common structures?
A. Pattern recognition receptors (PRRs)
B. Cytokines
C. Chemokines
D. T cells .
Answer Explanation
Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens.
PRRs play a crucial role in the proper function of the innate immune system and are germline-encoded host sensors, which detect molecules typical for the pathogens.
Choice B is incorrect because cytokines are not receptors but rather signaling molecules that regulate immunity.
Choice C is incorrect because chemokines are not receptors but rather signaling molecules that attract immune cells to sites of infection.
Choice D is incorrect because T cells are not receptors but rather white blood cells that assist B cells or directly kill infected cells.
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Q #2: Which cytotoxic lymphocyte granules contain serine proteases that induce apoptosis in target cells?.
A. Perforins.
B. Cytokines.
C. Granzymes.
D. Interferons.
Answer Explanation
Granzymes.
Granzymes are a family of serine proteases that are stored in and secreted from the cytotoxic granules of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells.
They work in synergy with perforin, a pore-forming toxin, to induce apoptosis in target cells.
Perforin is necessary for the delivery of granzyme B to the target cell cytosol where caspase-dependent and -independent pathways to apoptosis are activated.
Perforins (choice A) are pore-forming toxins that work in synergy with granzymes to induce apoptosis in target cells.
Cytokines (choice B) are signaling molecules that regulate immune responses but do not directly induce apoptosis in target cells.
Interferons (choice D) are a type of cytokine that play a role in immune responses but do not directly induce apoptosis in target cells.
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Q #3: Which hormone is responsible for the development of female secondary sexual characteristics such as breast development, menstrual cycle, and widening of hips?
A. Progesterone
B. Testosterone
C. Estrogen
D. FSH
Answer Explanation
The correct answer is choice C. Estrogen.
Estrogen is a steroid hormone responsible for the development of female secondary sexual characteristics such as breast development, menstrual cycle, and widening of hips.
Choice A, Progesterone, is not the correct answer because it is required to maintain pregnancy and delivery.
Choice B, Testosterone, is not the correct answer because it is a hormone produced by the testes which controls the development of male secondary sexual characteristics.
Choice D, FSH (Follicle Stimulating Hormone), is not the correct answer because it stimulates the growth of ovarian follicles in females and regulates spermatogenesis in males.
