Which of the following is an event that occurs in metaphase I of meiosis that causes variation?

The correct answer is C. Psoriasis is a chronic autoimmune skin condition characterized by the rapid buildup of skin cells, and it is considered a noninfectious disease. Chikungunya, dengue, and brucellosis are infectious diseases caused by specific pathogens.

The correct answer is B. When a volcano erupts, it releases built-up pressure and gases, similar to the fizzing of a can of soda when opened. Both involve the release of pressure and trapped substances, leading to an outward expulsion of materials.

The correct answer is B. The vermiform appendix is a small, tube-like structure that extends from the cecum, which is the first part of the large intestine. It is not associated with the jejunum, rectum, or ischium.

The correct answer is B. Objects A and B have the same mass, but B falls faster because it has less air resistance. Objects C and D have different masses, but C falls faster because it has a higher mass-to-surface-area ratio, which reduces the effect of air resistance.

The pharynx is primarily composed of muscle tissue. It plays a role in swallowing and is part of both the respiratory and digestive systems, which requires coordinated muscular activity.

The correct answer is A. A gene is a segment of DNA that contains the instructions for building a specific protein or performing a specific function.

The correct answer is B. Uracil is a nitrogenous base found in RNA, replacing thymine which is found in DNA. Adenine, guanine, and cytosine are common to both RNA and DNA.

The correct answer is B. Parathyroid hormone (PTH) regulates blood calcium levels by stimulating the release of calcium from bones, reabsorption of calcium in the kidneys, and absorption of calcium in the intestines. Norepinephrine, growth hormone, and melatonin do not play a primary role in calcium regulation.

The correct answer is B. Fertilization typically occurs in the fallopian tube, where the sperm can meet and fertilize the egg. The fertilized egg then travels to the uterus for implantation and development.

The correct answer is C. Lysosomes are membrane-bound organelles containing enzymes that break down cellular waste, debris, and foreign materials through intracellular digestion.