1. The primary function of the respiratory system is to:

A. Maintain body temperature
B. Deliver oxygen to the bloodstream and remove carbon dioxide
C. Produce antibodies for the immune system
D. Break down food molecules for energy

Correct answer: B

Rationale: The correct answer is B: 'Deliver oxygen to the bloodstream and remove carbon dioxide.' The primary function of the respiratory system is to facilitate gas exchange. When we breathe in, oxygen is inhaled and transported to the bloodstream, where it is delivered to cells for energy production. Simultaneously, carbon dioxide, a waste product of cellular metabolism, is removed from the bloodstream and exhaled. This process is vital for sustaining life and maintaining proper oxygen levels in the body. The respiratory system does not primarily regulate body temperature, produce antibodies, or break down food molecules for energy, making options A, C, and D incorrect.

2. Which element is a good conductor of electricity but is not a metal?

A. Copper
B. Silver
C. Graphite
D. Gold

Correct answer: C

Rationale: While metals are known for their conductivity, some non-metals like graphite also exhibit this property due to their unique electronic structure

3. When an atom gains or loses electrons, it becomes a(n):

A. Molecule
B. Isotope
C. Ion
D. Compound

Correct answer: C

Rationale: Gaining or losing electrons alters the atom's electron count and charge, creating a positively or negatively charged ion.

4. Diabetes mellitus is a chronic condition affecting blood sugar control. What is the main type of hormone deficiency associated with type 1 diabetes?

A. Insulin
B. Glucagon
C. Estrogen
D. Testosterone

Correct answer: A

Rationale: The correct answer is A: "Insulin." In type 1 diabetes, the main type of hormone deficiency is insulin. Insulin is produced by the pancreas and is crucial for regulating blood sugar levels by helping cells absorb glucose. In individuals with type 1 diabetes, the immune system mistakenly attacks and destroys insulin-producing beta cells in the pancreas, leading to a deficiency of insulin. This results in uncontrolled high blood sugar levels, which can have serious consequences if not managed properly. Glucagon, estrogen, and testosterone do not play a primary role in the hormone deficiency associated with type 1 diabetes.

5. What is the difference between polygenic inheritance and pleiotropy?

A. Polygenic inheritance involves multiple genes influencing one trait, while pleiotropy involves one gene affecting multiple traits.
B. Polygenic inheritance is found in simple Mendelian traits, while pleiotropy is found in complex traits.
C. Polygenic inheritance is always quantitative, while pleiotropy can be qualitative or quantitative.
D. Both involve multiple genes and multiple traits, but the specific mechanisms differ

Correct answer: A

Rationale: Rationale: - Polygenic inheritance refers to the situation where a trait is influenced by multiple genes, each contributing a small effect to the phenotype. These traits often show continuous variation and are not easily categorized into discrete categories. - Pleiotropy, on the other hand, occurs when a single gene influences multiple, seemingly unrelated traits. This means that a mutation in one gene can lead to multiple phenotypic effects across different traits or characteristics. - Therefore, the key difference between polygenic inheritance and pleiotropy lies in the number of genes involved in influencing a trait (multiple genes in polygenic inheritance vs. one gene in pleiotropy) and the direction of influence (one trait affected by multiple genes in polygenic inheritance vs. multiple traits affected by one gene in pleiotropy).