TEAS 7 practice test science

TEAS 7 practice test science Related

Review TEAS 7 practice test science related questions and content

Which type of mutation involves a change in the number of chromosomes?

  • A. Point mutation
  • B. Frameshift mutation
  • C. Missense mutation
  • D. Aneuploidy
Correct Answer: D

Rationale: A) Point mutation involves a change in a single nucleotide base pair within the DNA sequence.
B) Frameshift mutation involves the insertion or deletion of nucleotides, causing a shift in the reading frame of the genetic code.
C) Missense mutation involves a single nucleotide change that results in a codon that codes for a different amino acid.

D) Aneuploidy involves a change in the number of chromosomes, where an individual may have an extra chromosome (trisomy) or a missing chromosome (monosomy). Aneuploidy can lead to genetic disorders such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X). Changing the number of chromosomes is a characteristic feature of aneuploidy, making it the correct answer. Point mutation, frameshift mutation, and missense mutation do not involve a change in the number of chromosomes and are focused on alterations at the nucleotide level within the DNA sequence.

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Which organ serves as the human body's command center, integrating sensory information and coordinating movement and vital functions?

  • A. Lungs
  • B. Brain
  • C. Kidneys
  • D. Stomach
Correct Answer: B

Rationale: The brain is the human body's command center, responsible for integrating sensory information, coordinating movement, and regulating vital functions such as breathing, heart rate, and digestion. While the lungs, kidneys, and stomach perform crucial functions in the body, they do not have the central role of serving as the command center for these essential bodily processes. The lungs are primarily involved in respiration, the kidneys in filtering blood and regulating fluid balance, and the stomach in digestion. However, none of these organs have the comprehensive control over sensory integration, movement coordination, and vital functions like the brain does.

What phenomenon occurs when a wave encounters a change in medium causing a change in its speed and direction?

  • A. Refraction
  • B. Reflection
  • C. Diffraction
  • D. Interference
Correct Answer: A

Rationale: Refraction is the phenomenon that occurs when a wave encounters a change in medium, causing a change in its speed and direction. This change in speed and direction is due to the wave bending as it passes from one medium to another with a different density. It is essential to understand refraction as it plays a crucial role in various phenomena, such as the bending of light in lenses, the formation of rainbows, and the way seismic waves travel through the Earth's layers. Reflection, while also a wave phenomenon, involves the bouncing back of a wave when it encounters a boundary. Diffraction refers to the bending of waves around obstacles or through openings, and interference involves the combination of two or more waves to form a new wave pattern.

What happens to the concentration of hydrogen ions (\([H^+]\)) in a solution as the pH increases?

  • A. Increases
  • B. Decreases
  • C. Remains constant
  • D. Becomes neutral
Correct Answer: B

Rationale: As the pH increases, the concentration of hydrogen ions decreases. The relationship is inversely proportional

What is the role of surfactant in the respiratory system?

  • A. To trap dust particles
  • B. To increase lung compliance
  • C. To produce mucus
  • D. To generate oxygen during respiration
Correct Answer: B

Rationale: The correct answer is B: To increase lung compliance. Surfactant is a substance produced by type II alveolar cells in the lungs that reduces surface tension in the alveoli. This reduction in surface tension helps to increase lung compliance, making it easier for the lungs to expand and contract during breathing. Improved lung compliance is essential for efficient gas exchange in the respiratory system, facilitating oxygen uptake and carbon dioxide removal. Choices A, C, and D are incorrect because surfactant does not trap dust particles, produce mucus, or generate oxygen during respiration. Instead, its primary function lies in reducing surface tension to prevent alveolar collapse and improve lung compliance for optimal gas exchange.

What happens to the potential energy of an object as it falls freely near the Earth's surface?

  • A. Potential energy decreases
  • B. Potential energy increases
  • C. Potential energy remains constant
  • D. Potential energy becomes zero
Correct Answer: A

Rationale: As an object falls freely near the Earth's surface, its potential energy decreases. This decrease occurs because the gravitational potential energy is being converted into kinetic energy as the object accelerates due to gravity. According to the law of conservation of energy, the total mechanical energy (the sum of potential and kinetic energy) remains constant in the absence of non-conservative forces like air resistance. Choice B ('Potential energy increases') is incorrect because the object's potential energy is being converted into kinetic energy, leading to a decrease. Choice C ('Potential energy remains constant') is incorrect as the conversion of potential energy to kinetic energy results in a decrease in potential energy. Choice D ('Potential energy becomes zero') is incorrect because potential energy is not reduced to zero but is transformed into kinetic energy as the object falls.

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