1. Where does fertilization, the fusion of sperm and egg, typically occur in the human body?

A. Ovary
B. Uterus
C. Fallopian tube
D. Vagina

Correct answer: C

Rationale: The correct answer is C: Fallopian tube. Fertilization, the fusion of sperm and egg, typically occurs in the fallopian tube. After ovulation, the egg is released from the ovary and travels through the fallopian tube where it may encounter sperm for fertilization. The fertilized egg then moves to the uterus for implantation and development. The ovary releases the egg but fertilization occurs in the fallopian tube, making it the correct answer.

2. A child's toy block is a cube with side lengths of 5cm. What is its total surface area?

A. 25 sq cm
B. 50 sq cm
C. 125 sq
D. 150 sq cm

Correct answer: D

Rationale: Use the formula for surface area of a cube: 6 * (side length)^2 = 6 * (5cm)^2 = 125 sq cm.

3. What is the electron configuration of an atom?

A. The arrangement of electrons in an atom's orbitals.
B. The number of protons in an atom's nucleus.
C. The number of neutrons in an atom's nucleus.
D. The number of electrons in an atom's valence shell.

Correct answer: A

Rationale: The electron configuration of an atom refers to the arrangement of electrons in the atom's orbitals. This arrangement determines the atom's chemical properties and behavior. The number of protons in an atom's nucleus (option B) is known as the atomic number, while the number of neutrons in an atom's nucleus (option C) contributes to the atom's mass number. The number of electrons in an atom's valence shell (option D) is important for understanding the atom's reactivity and bonding behavior.

4. Biodiversity is important for healthy ecosystems because it:

A. Increases competition for resources
B. Provides stability and resilience to disturbances
C. Slows down nutrient cycling
D. Reduces the number of decomposers

Correct answer: B

Rationale: Rationale: Biodiversity refers to the variety of living organisms in a particular area. A diverse ecosystem is better able to withstand and recover from disturbances such as natural disasters, climate change, or human impacts. This is because different species play unique roles in the ecosystem, and a higher level of biodiversity means there are more species available to fulfill these roles. For example, if one species is negatively affected by a disturbance, other species may be able to compensate for its loss, maintaining the overall functioning of the ecosystem. Therefore, biodiversity provides stability and resilience to disturbances, making ecosystems healthier and more sustainable.

5. What is the general formula for an alkyl halide?

A. CnH2n
B. CnH2n+2
C. CnH2n-1X
D. CnH2nO

Correct answer: C

Rationale: The general formula for an alkyl halide is $C_nH_{2n-1}X$, where X represents a halogen (e.g., F, Cl, Br, I).

6. What is the main function of the epiglottis?

A. To store bile
B. To absorb nutrients
C. To prevent food from entering the trachea
D. To produce digestive enzymes

Correct answer: C

Rationale: Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the trachea during swallowing to prevent food and liquids from entering the airway. This action helps direct food and liquids into the esophagus, which leads to the stomach for digestion, while also protecting the respiratory system from potential blockages that could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as the epiglottis is not involved in storing bile, absorbing nutrients, or producing digestive enzymes.