1. What is the name for the hard, protective protein that makes up hair and nails?

A. Collagen
B. Keratin
C. Elastin
D. Fibrin

Correct answer: B

Rationale: The correct answer is B: Keratin. Keratin is the name for the hard, protective protein that makes up hair and nails. Collagen is a structural protein found in connective tissues, while elastin is a protein that allows tissues in the body to resume their shape after stretching. Fibrin is a protein involved in blood clotting. Understanding the different roles of these proteins can help in identifying the correct answer as keratin specifically pertains to hair and nails.

2. Chyle, a milky white fluid, is transported by lymphatic vessels from the:

A. Lungs
B. Intestines
C. Kidneys
D. Skin

Correct answer: B

Rationale: The correct answer is B: Intestines. Chyle is a milky white fluid that is formed in the small intestine during digestion, mainly from the absorption of dietary fats. It is rich in fats and lymphocytes. Lymphatic vessels in the intestines, called lacteals, absorb the chyle and transport it through the lymphatic system. Chyle eventually enters the bloodstream via the thoracic duct. The lungs are responsible for gas exchange, not the transport of chyle. The kidneys are involved in filtering blood and producing urine. The skin is the body's largest organ responsible for protection, temperature regulation, and sensation, but it is not involved in transporting chyle.

3. Which of the following is the MOST common symptom of angina pectoris, a condition related to insufficient blood flow to the heart?

A. Fever and chills.
B. Chest pain or discomfort.
C. Sudden onset of severe shortness of breath
D. Numbness or tingling in the extremities

Correct answer: B

Rationale: The correct answer is B: Chest pain or discomfort. Angina pectoris is characterized by chest pain or discomfort that occurs when the heart muscle does not receive enough oxygen-rich blood. This pain is often described as a squeezing, pressure, heaviness, or tightness in the chest. While other symptoms like fever, chills, shortness of breath, numbness, or tingling in the extremities can occur in various conditions, chest pain is the hallmark symptom of angina pectoris. It is important to recognize this symptom as it may indicate an underlying heart issue and prompt medical attention is crucial.

4. What is the function of ribosomal RNA (rRNA)?

A. Carries amino acids to the ribosomes
B. Reads th(a) Carries amino acids to the ribosomes: This is the function of transfer RNA (tRNA), not ribosomal RNA. (b) Reads the genetic code on mRNA: This is the function of the ribosomes as a whole, not just the ribosomal RNA. (d) Controls the rate of protein synthesis: This is a more complex process involving various factors, not solely ribosomal RNA. e genetic code on mRNA
C. Forms the structural framework of ribosomes
D. Controls the rate of protein synthesis

Correct answer: C

Rationale: Rationale: Ribosomal RNA (rRNA) plays a crucial role in forming the structural framework of ribosomes, which are the cellular organelles responsible for protein synthesis. Ribosomes consist of both protein and rRNA components, with rRNA providing the structural support necessary for the ribosome to function properly. This structural framework allows the ribosome to interact with messenger RNA (mRNA) and transfer RNA (tRNA) during the process of translation, where the genetic information encoded in mRNA is used to assemble proteins from amino acids. Therefore, the primary function of rRNA is to contribute to the structure and function of ribosomes, rather than directly carrying amino acids, reading the genetic code, or controlling the rate of protein synthesis.

5. The outermost layer of your skin, responsible for waterproofing and providing a barrier against pathogens, is the:

A. Stratum basale (Basal layer)
B. Stratum corneum
C. Stratum granulosum
D. Stratum spinosum

Correct answer: B

Rationale: The correct answer is B: Stratum corneum. The stratum corneum is the outermost layer of the epidermis, consisting of dead skin cells (corneocytes) that are continuously shed and replaced. This layer is responsible for waterproofing the skin and providing a barrier against pathogens, UV radiation, and other environmental factors. The stratum basale (A) is the deepest layer of the epidermis where new skin cells are produced. The stratum granulosum (C) is the layer of the epidermis where cells begin to flatten and keratinization begins. The stratum spinosum (D) is the layer above the stratum granulosum, where cells become interconnected by desmosomes. Therefore, the stratum corneum is specifically designed to fulfill the functions of waterproofing and protecting against pathogens.