1. During normal breathing, which muscle is the primary driver of inhalation by contracting and flattening to increase the volume of the thoracic cavity?

A. Diaphragm
B. Intercostal muscles
C. Abdominal muscles
D. Pectoral muscles

Correct answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation during normal breathing. When the diaphragm contracts and flattens, it increases the volume of the thoracic cavity, creating a negative pressure that allows air to rush into the lungs. The intercostal muscles also play a role in expanding the ribcage to assist with inhalation. However, the diaphragm is the main driver of the breathing process by creating the necessary space for the lungs to expand and fill with air.

2. What is the primary function of ribosomes in the cell?

A. To synthesize lipids and other cellular components
B. To package and transport proteins
C. To break down macromolecules
D. To translate mRNA into proteins

Correct answer: D

Rationale: Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C do not accurately describe the primary function of ribosomes in the cell.

3. 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.

4. Which term describes the quantity of matter in an object and is measured in kilograms or grams?

A. Weight
B. Mass
C. Volume
D. Density

Correct answer: B

Rationale: Mass is the term that describes the quantity of matter in an object. It is typically measured in kilograms or grams. Weight, on the other hand, is the force of gravity acting on an object and is measured in newtons. Volume is the amount of space an object occupies, typically measured in cubic units such as cubic meters or cubic centimeters. Density is the mass of an object per unit volume and is measured in units such as kilograms per cubic meter.

5. What is the purpose of the spindle apparatus in cell division?

A. To separate sister chromatids
B. To move chromosomes to opposite poles of the cell
C. To form a new nuclear envelope around each daughter cell
D. To synthesize new DNA

Correct answer: B

Rationale: Rationale: The spindle apparatus is a structure composed of microtubules that plays a crucial role in cell division (mitosis and meiosis). Its main purpose is to ensure the proper separation and distribution of chromosomes to opposite poles of the cell during cell division. This process is essential for the formation of two genetically identical daughter cells in mitosis or four haploid daughter cells in meiosis. Option A is incorrect because the separation of sister chromatids specifically refers to the role of the kinetochore fibers within the spindle apparatus. Option C is incorrect because the formation of a new nuclear envelope occurs after the chromosomes have been properly segregated. Option D is incorrect because DNA synthesis does not occur within the spindle apparatus; it takes place during the S phase of the cell cycle.