Correct Answer: B

Rationale: The correct answer is B. Mendel's laws consist of the law of segregation, which states that each parent passes one allele for each trait, and the law of independent assortment, which explains that genes for different traits are inherited independently. Choice A is incorrect because 'law of expression' is not one of Mendel's laws. Choice C is incorrect because 'law of dominance' and 'law of recessiveness' do not represent the two main laws proposed by Mendel. Choice D is incorrect because 'law of mutation' and 'law of crossing over' are not part of Mendel's original laws.

Correct Answer: C

Rationale: Neon is the least reactive among the given elements because it belongs to the noble gases group in the periodic table. Noble gases have a full valence shell of electrons, making them highly stable and least likely to react with other elements. Fluorine is the most reactive non-metal due to its high electronegativity. Silicon is a metalloid with moderate reactivity, falling between metals and nonmetals. Gallium is a metal with higher reactivity compared to Neon, but it is not as reactive as Fluorine.

Correct Answer: B

Rationale: The correct answer is B - Frontal/Coronal Plane. This plane divides the body into anterior (front) and posterior (back) halves. The sagittal plane divides the body into left and right halves, the transverse plane separates the body into superior (upper) and inferior (lower) portions. The horizontal plane is not a standard anatomical term for body division and does not provide division into front and back halves.

Correct Answer: D

Rationale: The correct answer is D, the left ventricle. The left ventricle is the largest and strongest chamber of the heart. It is responsible for pumping oxygenated blood to the entire body through the aorta, playing a crucial role in the circulatory system. Choices A, B, and C are incorrect. The right atrium receives deoxygenated blood from the body, the left atrium receives oxygenated blood from the lungs, and the right ventricle pumps deoxygenated blood to the lungs for oxygenation. However, the left ventricle is the largest chamber and performs the vital function of pumping oxygen-rich blood to the body.

Correct Answer: B

Rationale: The correct answer is B: Neck. A pivot joint, as found in the neck, allows for rotational movement around a single axis. This type of joint is essential for movements like shaking your head 'no' or looking left and right. Choices A, C, and D are incorrect because the hip, shoulder, and elbow joints are examples of ball-and-socket joints, which allow for a wide range of motion in multiple directions, not just rotational movement around a single axis like a pivot joint.