what is the difference between polygenic inheritance and pleiotropy

ATI TEAS 7

ati teas 7 science

1. What is the difference between polygenic inheritance and pleiotropy?

A. Polygenic inheritance involves multiple genes influencing one trait, while pleiotropy involves one gene affecting multiple traits.
B. Polygenic inheritance is found in simple Mendelian traits, while pleiotropy is found in complex traits.
C. Polygenic inheritance is always quantitative, while pleiotropy can be qualitative or quantitative.
D. Both involve multiple genes and multiple traits, but the specific mechanisms differ

Correct answer: A

Rationale: - Polygenic inheritance refers to the situation where a trait is influenced by multiple genes, each contributing a small effect to the phenotype. These traits often show continuous variation and are not easily categorized into discrete categories. - Pleiotropy, on the other hand, occurs when a single gene influences multiple, seemingly unrelated traits. This means that a mutation in one gene can lead to multiple phenotypic effects across different traits or characteristics. - Therefore, the key difference between polygenic inheritance and pleiotropy lies in the number of genes involved in influencing a trait (multiple genes in polygenic inheritance vs. one gene in pleiotropy) and the direction of influence (one trait affected by multiple genes in polygenic inheritance vs. multiple traits affected by one gene in pleiotropy).

2. Which of the following biological macromolecules is non-soluble, composed of hydrocarbons, and acts as an important source of energy storage for the body?

A. carbohydrates
B. nucleic acids
C. lipids
D. proteins

Correct answer: C

Rationale: Lipids are non-soluble biological macromolecules composed mostly of hydrocarbons such as fatty acids. They act as an essential source of energy storage for the body, providing efficient storage of energy in the form of fats. Carbohydrates are also an energy source for the body, but lipids excel in long-term energy storage. Nucleic acids are not known for energy storage; instead, they are involved in genetic information transmission and protein synthesis. Proteins play diverse roles in the body, such as enzymatic functions, structural support, and immune response, but they are not primarily known as a source of energy storage.

3. Which of the following is the main function of the skin?

A. To protect the body from harm
B. To regulate body temperature
C. To produce hormones
D. To sense touch, temperature, and pain

Correct answer: A

Rationale: Rationale: A) To protect the body from harm: The skin acts as a physical barrier that protects the body from external threats such as pathogens, UV radiation, and physical injuries. It helps prevent infections and dehydration, making it a crucial function of the skin. B) To regulate body temperature: While the skin does play a role in regulating body temperature through processes like sweating and vasodilation/vasoconstriction, its primary function is protection. C) To produce hormones: Hormone production is primarily carried out by endocrine glands such as the pituitary gland, thyroid gland, and adrenal glands, not the skin. D) To sense touch, temperature, and pain: The skin contains sensory receptors that allow us to perceive touch, temperature, and pain, but this function is secondary to its main role of protecting the body from harm.

4. The Human Genome Project is a worldwide research project launched in 1990 to map the entire human genome. Although the Project was faced with the monumental challenge of analyzing tons of data, its objective was completed in 2003, two years ahead of its deadline. Which of the following inventions likely had the greatest impact on this project?

A. The sonogram
B. X-ray diffraction
C. The microprocessor
D. Magnetic Resonance Imaging (MRI)

Correct answer: C

Rationale: The microprocessor, a key component of modern computers, played a crucial role in the success of the Human Genome Project. The ability of microprocessors to process vast amounts of data quickly and efficiently allowed scientists to analyze the massive amounts of genetic information generated by the project. This technological advancement significantly accelerated the pace of genome sequencing and data analysis, ultimately leading to the completion of the project ahead of schedule. Choices A, B, and D are incorrect. The sonogram is used for imaging in medical diagnostics, X-ray diffraction is a technique for studying the structure of materials at the atomic level, and Magnetic Resonance Imaging (MRI) is a medical imaging technique that uses magnetic fields and radio waves to produce detailed images of the body. While these inventions have their own importance in various fields, they did not have the same impact on the Human Genome Project as the microprocessor did.

5. Which of the following terms refers to a muscle twitch, a single forceful contraction of a muscle fiber?

A. Tetanus
B. Tremor
C. Fasciculation
D. Rigidity

Correct answer: C

Rationale: The correct term for a muscle twitch, a single forceful contraction of a muscle fiber, is 'Fasciculation' (choice C). Fasciculation specifically describes this phenomenon. 'Tetanus' (choice A) refers to sustained muscle contraction, 'Tremor' (choice B) indicates a shaky or quivering movement, and 'Rigidity' (choice D) denotes stiffness or inflexibility in muscles. Therefore, choices A, B, and D are incorrect in the context of a single forceful contraction of a muscle fiber.