TEAS 7 science practice

TEAS 7 science practice Related

Review TEAS 7 science practice related questions and content

What is the process by which a population gradually loses genetic variation?

  • A. Founder effect
  • B. Bottleneck effect
  • C. Gene flow
  • D. Speciation
Correct Answer: B

Rationale: A) Founder effect: This occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not necessarily result in a gradual loss of genetic variation in an existing population.
B) Bottleneck effect: This process occurs when a population is drastically reduced in size, leading to a significant loss of genetic variation due to the limited number of individuals contributing to the gene pool. The reduced genetic diversity can have long-term effects on the population's ability to adapt to environmental changes.
C) Gene flow: This refers to the movement of genes between populations, which can introduce new genetic variation and prevent populations from diverging. Gene flow does not lead to a gradual loss of genetic variation within a population.
D) Speciation: This is the process by which new species evolve from existing species, often involving the accumulation of genetic differences that l

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What is kwashiorkor, a protein deficiency disease, characterized by?

  • A. Muscle wasting
  • B. Night blindness
  • C. Scurvy
  • D. Rickets
Correct Answer: A

Rationale: Kwashiorkor is a severe acute malnutrition condition resulting from insufficient dietary protein intake. It is characterized by symptoms such as edema, skin lesions, an enlarged liver with fatty infiltrates, and notably, muscle wasting. Muscle wasting occurs as the body breaks down muscle tissue to obtain essential amino acids for vital functions. Night blindness (option B) is associated with vitamin A deficiency, scurvy (option C) results from a lack of vitamin C, and rickets (option D) is caused by a deficiency in vitamin D, calcium, or phosphate.

Which of the following conditions is characterized by a wasting or decrease in muscle mass?

  • A. Hypertrophy
  • B. Atrophy
  • C. Spasticity
  • D. Myopathy
Correct Answer: B

Rationale: Atrophy is the correct answer as it is characterized by a wasting or decrease in muscle mass. Hypertrophy, on the other hand, refers to an increase in muscle size. Spasticity is associated with increased muscle tone due to continuous contraction of muscles. Myopathy, on the other hand, is a broad term used to describe various muscle diseases affecting muscle tissue, which may or may not involve muscle wasting.

What property of a substance remains constant regardless of changes in its location in the universe?

  • A. Mass
  • B. Weight
  • C. Density
  • D. Volume
Correct Answer: A

Rationale: Mass is the amount of matter in an object and remains constant regardless of its location in the universe. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the gravitational pull at different locations. Density and volume can change based on the conditions the substance is in, so they are not constant properties. Therefore, the correct answer is mass as it does not change with changes in location.

Which part of the brainstem is responsible for controlling vital functions such as heart rate, blood pressure, and breathing?

  • A. Medulla oblongata
  • B. Pons
  • C. Midbrain
  • D. Cerebellum
Correct Answer: A

Rationale: The medulla oblongata is the correct answer. It is responsible for controlling vital functions such as heart rate, blood pressure, and breathing. This part of the brainstem contains centers that regulate these essential autonomic functions to maintain homeostasis in the body. The pons and midbrain are also parts of the brainstem, but they are not primarily responsible for controlling these vital functions. The cerebellum, on the other hand, is involved in coordination and balance, not in regulating vital functions like heart rate, blood pressure, and breathing.

During embryonic development, most vertebrates exhibit structures called pharyngeal pouches. These pouches eventually develop into different structures in various vertebrate groups, such as the human jaw and inner ear. Pharyngeal pouches are an example of:

  • A. Analogous structures with different evolutionary origins but similar functions
  • B. Homologous structures with a common evolutionary origin but diverse functions
  • C. Vestigial structures that no longer serve a vital function in some organisms
  • D. Atavisms, the reappearance of a trait absent in recent generations
Correct Answer: B

Rationale: Pharyngeal pouches in vertebrates are an example of homologous structures because they share a common evolutionary origin. Despite developing into different structures in various vertebrate groups, such as the jaw and inner ear in humans, these structures originated from the same ancestral feature. This concept of homology highlights the evolutionary relationship between different species and how structures can be modified over time to serve different functions while retaining a common origin. Choice A is incorrect because analogous structures have similar functions but different evolutionary origins, which does not apply to pharyngeal pouches. Choice C is incorrect as vestigial structures are remnants of features that were functional in ancestors but have reduced or lost their original function, which is not the case for pharyngeal pouches. Choice D is incorrect because atavisms refer to the reappearance of traits absent in recent generations, which is not the characteristic of pharyngeal pouches.

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