1. A collection of organs working together to perform a specific physiological function is known as a(n):

A. Tissue
B. Organ system
C. Organelle
D. Organ

Correct answer: B

Rationale: The correct answer is B: Organ system. An organ system is a group of organs that work together to carry out a specific function in the body. While an organ is made up of different types of tissues that work together, an organ system involves multiple organs collaborating to perform more complex tasks. Tissues (option A) are groups of similar cells working together, organelles (option C) are structures within cells that have specific functions, and organs (option D) are made up of tissues and perform specific functions, but the term 'organ system' specifically refers to a higher level of organization involving multiple organs working in coordination.

2. Which structure in the respiratory system serves as the "windpipe" that conducts air from the larynx to the bronchi?

A. Trachea
B. Larynx
C. Bronchi
D. Alveoli

Correct answer: A

Rationale: The correct answer is A: Trachea. The trachea, also known as the windpipe, is a tube-like structure in the respiratory system that connects the larynx to the bronchi. It serves as the main airway for the passage of air into and out of the lungs. The larynx is commonly known as the voice box and is responsible for producing sound. The bronchi are the two branches that stem from the trachea and lead to the lungs, where they further divide into smaller airways. The alveoli are tiny air sacs in the lungs where gas exchange occurs. Therefore, the trachea is the correct answer as it directly conducts air from the larynx to the bronchi.

3. What is the function of introns in eukaryotic genes?

A. They code for protein sequences.
B. They are involved in gene regulation.
C. They are removed during mRNA processing.
D. They are non-functional remnants of ancient DNA.

Correct answer: C

Rationale: Rationale: A) Introns do not code for protein sequences. Exons are the segments of DNA that code for proteins. B) While introns can indirectly influence gene regulation, their primary function is not directly involved in gene regulation. C) Introns are non-coding regions of DNA that are transcribed into pre-mRNA but are removed during mRNA processing through a process called splicing. This allows only the exons to be included in the mature mRNA that will be translated into proteins. D) While introns were once thought to be non-functional remnants of ancient DNA, research has shown that they can have regulatory functions and play a role in gene expression.

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. Approximately how many muscles are there in the human body?

A. 100
B. 100
C. 600
D. Over 600

Correct answer: D

Rationale: The correct answer is D. There are over 600 muscles in the human body. Muscles are responsible for movement, posture, and generating heat in the body. The exact number of muscles can vary slightly from person to person, but it is generally accepted that there are over 600 muscles in the human body. These muscles work together to allow us to perform various movements and activities throughout our daily lives.

6. Which respiratory structure is responsible for the production of mucus to trap particles and for the movement of cilia to sweep mucus and trapped particles out of the respiratory tract?

A. Trachea
B. Larynx
C. Bronchi
D. Respiratory epithelium

Correct answer: D

Rationale: The correct answer is D: Respiratory epithelium. The respiratory epithelium is a specialized tissue lining the respiratory tract that produces mucus to trap particles and contains cilia that beat in a coordinated manner to move the mucus and trapped particles out of the respiratory tract. The trachea, larynx, and bronchi are all structures within the respiratory system, but they do not directly produce mucus or have cilia for sweeping particles. Therefore, the respiratory epithelium is the specific structure responsible for these functions.