1. The network of vessels and ducts responsible for draining excess fluid and waste products from tissues is the:

A. Circulatory system
B. Digestive system
C. Lymphatic system
D. Respiratory system

Correct answer: C

Rationale: The correct answer is C: Lymphatic system. The lymphatic system is a network of vessels and ducts that play a crucial role in maintaining fluid balance in the body by draining excess fluid and waste products from tissues. Unlike the circulatory system (A), which primarily transports blood, the lymphatic system is specifically designed for this drainage function. The digestive system (B) is responsible for breaking down food and absorbing nutrients, while the respiratory system (D) is involved in the exchange of gases. Therefore, the lymphatic system is the correct answer for this question as it is uniquely tasked with managing tissue fluid balance and waste removal.

2. How does the acceleration of an object change if the force acting on it is doubled?

A. Acceleration is halved
B. Acceleration doubles
C. Acceleration remains unchanged
D. Acceleration quadruples

Correct answer: b

Rationale: According to Newton's second law (F = ma), if force is doubled and mass remains constant, acceleration doubles.

3. What is the primary function of hair on the human body?

A. Insulation
B. Sensory perception
C. Protection
D. Vitamin D synthesis

Correct answer: A

Rationale: The primary function of hair on the human body is insulation. Hair acts as a protective layer to help regulate body temperature by trapping heat close to the skin. This insulation property is especially important in colder climates to prevent excessive heat loss from the body. While hair can also provide some level of protection from external elements and minor injuries, its main role is to insulate the body. Sensory perception is mainly attributed to nerve endings in the skin rather than hair. Vitamin D synthesis is primarily dependent on exposure to sunlight rather than hair. Therefore, option A, insulation, is the correct answer.

4. In the context of the cardiac cycle, the P wave on an electrocardiogram (ECG) represents:

A. Atrial depolarization
B. Ventricular depolarization
C. Atrial repolarization
D. Ventricular repolarization

Correct answer: A

Rationale: The correct answer is A: "Atrial depolarization." The P wave on an ECG represents the depolarization of the atria, specifically the spread of electrical activity through the atria causing them to contract and push blood into the ventricles. This is the first wave observed on the ECG and signifies the beginning of the cardiac cycle. Ventricular depolarization is represented by the QRS complex, atrial repolarization is typically not visible on a standard ECG due to its timing with the QRS complex, and ventricular repolarization is represented by the T wave. Therefore, option A is the most appropriate choice in this context.

5. Which of the following is NOT a source of genetic variation in a population?

A. Mutations in genes
B. Genetic drift (random fluctuations in allele frequencies)
C. Gene flow (movement of genes between populations)
D. Blending inheritance (traits of parents are averaged in offspring)

Correct answer: D

Rationale: Rationale: A) Mutations in genes: Mutations are changes in the DNA sequence that can introduce new alleles into a population, leading to genetic variation. B) Genetic drift (random fluctuations in allele frequencies): Genetic drift refers to random changes in allele frequencies in a population, which can lead to genetic variation through chance events. C) Gene flow (movement of genes between populations): Gene flow occurs when individuals move between populations, bringing new alleles with them and increasing genetic variation within populations. D) Blending inheritance (traits of parents are averaged in offspring): Blending inheritance was a historical theory that suggested offspring inherit a blend of traits from their parents, leading to a reduction in genetic variation over time. However, this concept has been disproven by the understanding of Mendelian genetics, where traits are inherited independently and do not blend together. Therefore, blending inheritance does not contribute

6. Which hormone stimulates the release of pancreatic enzymes and bile?

A. Gastrin
B. Insulin
C. Cholecystokinin (CCK)
D. Glucagon

Correct answer: C

Rationale: The correct answer is C: Cholecystokinin (CCK). Cholecystokinin is a hormone produced by the small intestine in response to the presence of food, especially fats and proteins. It stimulates the release of pancreatic enzymes from the pancreas and bile from the gallbladder to aid in digestion. Gastrin is a hormone that stimulates the release of gastric acid in the stomach. Insulin and glucagon are hormones involved in regulating blood sugar levels, not the release of pancreatic enzymes and bile. Therefore, CCK is the hormone responsible for stimulating the release of pancreatic enzymes and bile in the digestive process.