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 force opposes the relative motion between surfaces in contact?

A. Tension force
B. Frictional force
C. Gravitational force
D. Magnetic force

Correct answer: b

Rationale: Friction is the force that opposes motion between surfaces in contact.

3. What is the "lock-and-key" model?

A. Protein folding
B. Enzyme-substrate interaction
C. Muscle contraction
D. Blood clotting

Correct answer: B

Rationale: Rationale: The "lock-and-key" model is a concept used to describe the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site is like a lock that can only be opened by the specific substrate molecule, which acts as the key. This specific binding ensures that enzymes catalyze specific reactions and do not interact with other molecules indiscriminately. Protein folding (option A) refers to the process by which a protein adopts its functional three-dimensional structure, but it is not specifically related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are biological processes that involve complex mechanisms but are not directly related to the lock-and-key model of enzyme-substrate interaction.

4. Which of the following is a condition characterized by inflammation and narrowing of the airways, leading to symptoms such as wheezing, coughing, and shortness of breath?

A. Pneumonia
B. Tuberculosis
C. Asthma
D. Emphysema

Correct answer: C

Rationale: The correct answer is C: Asthma. Asthma is a chronic condition that involves inflammation and narrowing of the airways, leading to symptoms like wheezing, coughing, and shortness of breath. Pneumonia (A) is an infection of the lungs, not a chronic inflammatory condition like asthma. Tuberculosis (B) is a bacterial infection that primarily affects the lungs and does not typically manifest with symptoms like wheezing. Emphysema (D) is a lung condition characterized by damage to the air sacs in the lungs, not inflammation and narrowing of the airways like asthma.

5. How many bones are there in the adult human skeleton?

A. 126
B. 206
C. 300
D. 525

Correct answer: D

Rationale: The correct answer is D: 525. The adult human skeleton consists of 206 bones. However, when accounting for individual bones, many of them are paired (like the ribs and vertebrae), bringing the total count to 206 individual bones but 525 in total when considering pairs. This includes bones in the skull, spine, ribs, arms, hands, pelvis, legs, and feet. So, while there are 206 individual bones, the total number of bones in the adult human skeleton is 525 when considering pairs.

6. 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.