ATI TEAS 7
TEAS 7 science quizlet
1. What is the process of converting DNA into a protein called?
- A. Transcription
- B. Translation
- C. Replication
- D. Mutation
Correct answer: B
Rationale: Translation is the correct answer. It is the process of converting the information in mRNA into a sequence of amino acids to form a protein. Transcription (Choice A) is the process of copying a segment of DNA into RNA. Replication (Choice C) is the process of making an identical copy of DNA. Mutation (Choice D) refers to a change in the DNA sequence that can lead to variations in proteins, but it is not the process of converting DNA into a protein.
2. The number of protons in an atom determines its:
- A. Mass number
- B. Atomic number
- C. Atomic weight
- D. Valence electron count
Correct answer: B
Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.
3. What is the principle behind optical fibers used in communication?
- A. Reflection of light within the fiber
- B. Refraction of light due to different densities within the fiber
- C. Total internal reflection guiding light through the fiber core
- D. Diffraction of light around bends in the fiber
Correct answer: C
Rationale: Optical fibers used in communication rely on the principle of total internal reflection guiding light through the fiber core. Total internal reflection occurs when light traveling through the core of the fiber is reflected back into the core due to the higher refractive index of the core compared to the cladding. This reflection ensures that the light remains confined within the core and propagates along the fiber without significant loss, allowing for efficient transmission of signals over long distances in optical communication systems. Choice A is incorrect because optical fibers do not primarily rely on simple reflection; instead, they utilize total internal reflection to guide light. Choice B is incorrect as the primary principle is not the refraction of light due to different densities within the fiber, but rather total internal reflection. Choice D is incorrect as diffraction is not the main principle behind optical fibers, which mainly rely on total internal reflection to guide light through the fiber core.
4. Which of the following glands helps regulate calcium levels?
- A. Osteotoid gland
- B. Pineal gland
- C. Parathyroid glands
- D. Thymus gland
Correct answer: C
Rationale: The correct answer is C: Parathyroid glands. The parathyroid glands are responsible for regulating calcium levels in the body. They produce parathyroid hormone (PTH), which helps control calcium levels in the blood by acting on the bones, kidneys, and intestines. The other options, such as the osteotoid gland, pineal gland, and thymus gland, do not play a significant role in calcium regulation. The osteotoid gland is a fictitious term, the pineal gland is involved in regulating sleep-wake cycles and producing melatonin, and the thymus gland is part of the immune system and plays a role in T-cell maturation.
5. During which of the following stages does crossing over occur?
- A. Mitosis Prophase
- B. Meiosis Prophase I
- C. Meiosis Prophase II
- D. Interphase
Correct answer: B
Rationale: Crossing over occurs during Prophase I of meiosis. This stage is specifically associated with genetic recombination, where homologous chromosomes exchange genetic material. This process contributes to genetic diversity by creating new combinations of alleles. Choices A, C, and D are incorrect. In mitosis, crossing over does not occur as it involves the separation of replicated chromosomes. Meiosis Prophase II is focused on the reformation of nuclei and does not involve crossing over. Interphase is a stage where the cell prepares for division and is not associated with crossing over.
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