1. What is the function of arrector pili muscles?

A. To control sweat production
B. To contract and cause goosebumps
C. To produce sebum
D. To sense touch

Correct answer: B

Rationale: The correct answer is B: 'To contract and cause goosebumps.' Arrector pili muscles are small muscles attached to hair follicles in the skin. When these muscles contract, they cause the hair to stand upright, resulting in the appearance of goosebumps. This physiological response is a remnant of our evolutionary past when our ancestors had more hair, and the raised hair helped to trap air for insulation or to make them look larger when threatened. Therefore, the function of arrector pili muscles is not to control sweat production (A), produce sebum (C), or sense touch (D), but rather to create the physical response of goosebumps.

2. What is the term for the number of moles of solute per liter of solution?

A. Molarity
B. Molality
C. Normality
D. Concentration

Correct answer: A

Rationale: Molarity is defined as the number of moles of solute per liter of solution. The other choices are different concentration units.

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

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

Correct answer: C

Rationale: The correct answer is C: "Fasciculation." A muscle twitch refers to the involuntary contraction of a small group of muscle fibers. Tetanus (choice A) is a sustained contraction of a muscle caused by rapid stimulation. Trembling (choice B) is the shaking or quivering of muscles. Rigidity (choice D) refers to stiffness or inflexibility in muscles. Fasciculation is the term that specifically describes a muscle twitch, which is a single forceful contraction of a muscle fiber. Therefore, choice C is the most appropriate term for this scenario.

4. What disease is characterized by progressive muscle weakness and wasting?

A. Muscular dystrophy
B. Myositis
C. Fibromyalgia
D. Carpal tunnel syndrome

Correct answer: A

Rationale: The correct answer is A: Muscular dystrophy. Muscular dystrophy is a genetic disorder characterized by progressive muscle weakness and wasting over time. It primarily affects skeletal muscles, leading to difficulties in movement and muscle function. Myositis is an inflammatory condition affecting the muscles, but it may not always result in progressive muscle weakness and wasting. Fibromyalgia is a chronic pain disorder characterized by widespread musculoskeletal pain and fatigue, not necessarily progressive muscle weakness. Carpal tunnel syndrome is a compression neuropathy affecting the median nerve in the wrist, leading to symptoms like numbness and tingling in the hand, but it does not cause progressive muscle weakness and wasting like muscular dystrophy does.

5. What is the name of the structure that packages DNA in eukaryotic cells?

A. Nucleosome
B. Chromatin
C. Histone
D. Centromere

Correct answer: A

Rationale: Rationale: - A nucleosome is the basic structural unit of DNA packaging in eukaryotic cells. It consists of DNA wrapped around a core of histone proteins. - Chromatin refers to the complex of DNA and proteins found in the nucleus of a eukaryotic cell, including nucleosomes. - Histones are the proteins around which DNA is wrapped to form nucleosomes. - Centromere is a region of a chromosome where the two sister chromatids are joined and to which spindle fibers attach during cell division.

6. What are the building blocks of proteins?

A. Sugars
B. Fatty acids
C. Amino acids
D. Nucleotides

Correct answer: C

Rationale: Rationale: Proteins are macromolecules made up of long chains of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form polypeptide chains, which then fold into specific three-dimensional structures to carry out various functions in the body. Sugars (A) are the building blocks of carbohydrates, fatty acids (B) are the building blocks of lipids, and nucleotides (D) are the building blocks of nucleic acids like DNA and RNA.