1. What is the term for the first exposure to a specific pathogen, leading to the development of an initial immune response?

A. Primary immune response
B. Secondary immune response
C. Hypersensitivity reaction
D. Immunological tolerance

Correct answer: A

Rationale: The correct answer is A: 'Primary immune response.' The primary immune response refers to the initial encounter with a specific pathogen, which triggers the immune system to respond by producing antibodies and memory cells. This process lays the foundation for the secondary immune response, which occurs upon subsequent exposure to the same pathogen. The primary immune response is characterized by the lag time in antibody production as the immune system is mobilized to combat the new threat. In contrast, the secondary immune response is faster and more robust due to the presence of memory cells from the primary response. Hypersensitivity reactions involve an exaggerated immune response to an antigen, while immunological tolerance refers to the immune system's ability to recognize self from non-self to prevent autoimmunity.

2. A birdbath has a hemispherical bowl with a diameter of 30cm. What is its volume?

A. 675 cu cm
B. 1350 cu cm
C. 2700 cu cm
D. 4050 cu cm

Correct answer: C

Rationale: Use half the formula for a sphere's volume: (2/3) * Ï€ * (radius)^3. Calculate the radius (15cm) and substitute: (2/3) * Ï€ * (15cm)^3 â‰ˆ 2700 cu cm.

3. The process by which a cell divides to produce two daughter cells is called:

A. Mitosis
B. Meiosis
C. Differentiation
D. Transformation

Correct answer: A

Rationale: The correct answer is A: "Mitosis." Mitosis is the process of cell division in which a cell duplicates its chromosomes and divides into two identical daughter cells. This is a crucial mechanism for growth, repair, and maintenance of multicellular organisms. Meiosis (option B) is a different type of cell division that produces gametes with half the number of chromosomes. Differentiation (option C) refers to the process by which cells become specialized for specific functions. Transformation (option D) is a term used in molecular biology to describe the uptake of foreign DNA by a cell. In this question, the specific process of cell division leading to the production of two daughter cells aligns with mitosis.

4. Which organ produces insulin?

A. Pancreas
B. Liver
C. Stomach
D. Kidneys

Correct answer: A

Rationale: Rationale: Insulin is a hormone that regulates blood sugar levels by facilitating the uptake of glucose into cells for energy production or storage. The pancreas is an organ located behind the stomach that plays a crucial role in producing insulin. Specialized cells within the pancreas, called beta cells, are responsible for synthesizing and secreting insulin in response to changes in blood glucose levels. Therefore, the pancreas is the organ that produces insulin.

5. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

A. Dendrite
B. Myelin sheath
C. Synapse
D. Cell body

Correct answer: b

Rationale: The correct answer is B: Myelin sheath. The myelin sheath is a fatty substance that surrounds the axon of a neuron, acting as an insulator to speed up the transmission of nerve impulses. It does this by creating gaps called nodes of Ranvier where the nerve impulses jump from one node to the next, allowing for faster signal conduction. Dendrites are branch-like extensions that receive signals from other neurons, the synapse is the junction between two neurons where neurotransmitters are released, and the cell body contains the nucleus and organelles of the neuron, but it is the myelin sheath that specifically insulates and speeds up the transmission of nerve impulses along the axon.

6. What is the building block of RNA?

A. Amino acid
B. Nucleotide
C. Protein
D. Fatty acid

Correct answer: B

Rationale: Rationale: A) Amino acid: Amino acids are the building blocks of proteins, not RNA. B) Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.