Nursing Elites

1. What is the difference between homologous chromosomes and sister chromatids?

• A. Homologous chromosomes have the same genes but may have different alleles, while sister chromatids are identical copies of the same chromosome.
• B. Homologous chromosomes are only found in diploid cells, while sister chromatids are found in both haploid and diploid cells.
• C. Both homologous chromosomes and sister chromatids are genetically identical, but only sister chromatids separate during mitosis.
• D. Both homologous chromosomes and sister chromatids can separate during mitosis, but only homologous chromosomes have different alleles.

Correct answer: A

Rationale: Rationale: - Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene). - Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle. - During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.

2. Myelin sheath, a fatty substance, insulates nerve fibers. What type of tissue is the myelin sheath derived from?

• A. Epithelial tissue
• B. Muscle tissue
• C. Nervous tissue (glial cells)
• D. Connective tissue

Correct answer: C

Rationale: The myelin sheath is derived from nervous tissue, specifically from glial cells, which are non-neuronal cells that support and protect neurons in the nervous system. Glial cells, such as Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system, produce the myelin sheath to insulate nerve fibers and enhance the speed of nerve impulse conduction. Epithelial tissue forms the protective covering of internal and external surfaces, muscle tissue is responsible for movement, and connective tissue provides support and structure to the body. Therefore, the correct answer is C: Nervous tissue (glial cells).

3. Edema is a condition characterized by swelling caused by a buildup of lymph fluid. What factors can contribute to edema?

• A. Regular exercise
• B. Maintaining a healthy weight
• C. Poor circulation or blockage in the lymphatic system
• D. Proper hydration

Correct answer: C

Rationale: Edema is a condition where there is an abnormal accumulation of fluid in the body tissues, leading to swelling. Poor circulation or blockage in the lymphatic system can contribute to edema by hindering the proper drainage of lymph fluid. When the lymphatic system is not functioning efficiently, it can result in fluid retention and swelling in the affected areas. Regular exercise and maintaining a healthy weight can actually help improve circulation and lymphatic flow, reducing the risk of edema. Proper hydration is important for overall health but specifically does not directly contribute to the development of edema as poor circulation or lymphatic blockages do.

4. Immunoglobulin G (IgG) is the most abundant antibody type, responsible for:

• A. Immediate allergic reactions
• B. Neutralizing toxins and viruses
• C. Activating other immune cells
• D. Protecting newborns from infections

Correct answer: B

Rationale: The correct answer is B: 'Neutralizing toxins and viruses.' Immunoglobulin G (IgG) is the most abundant antibody type in the blood and tissues. It plays a crucial role in neutralizing toxins and viruses by binding to them and marking them for destruction by other immune cells. IgG is also involved in opsonization, which enhances phagocytosis of pathogens by immune cells. While IgE is primarily responsible for immediate allergic reactions, IgG's main functions are related to immunity against pathogens rather than allergic responses. Activating other immune cells is typically associated with antibodies like IgM, while protecting newborns from infections is mainly attributed to maternal IgG antibodies passed on during pregnancy. Therefore, option B is the most accurate description of IgG's role in the immune system.

5. Which of the following is the main organ responsible for storing energy?

• A. Liver
• B. Heart
• C. Kidneys
• D. Adipose tissue

Correct answer: D

Rationale: Rationale: - Adipose tissue, commonly known as body fat, is the main organ responsible for storing energy in the form of triglycerides. - The liver plays a role in energy metabolism by regulating glucose levels and storing glycogen, but its primary function is not energy storage. - The heart is a muscular organ responsible for pumping blood throughout the body and does not play a significant role in energy storage. - The kidneys are vital organs responsible for filtering blood and regulating fluid balance, but they are not primarily involved in energy storage.

6. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: c

Rationale: The primary function of the myelin sheath that surrounds some axons in the nervous system is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer, which helps nerve impulses travel faster along the axon by allowing them to 'jump' from one node of Ranvier to the next, a process known as saltatory conduction. This increases the efficiency and speed of signal transmission, enabling rapid communication within the nervous system. Therefore, option C is the correct answer as it accurately describes the role of the myelin sheath in enhancing the speed of nerve impulse transmission.

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