Correct Answer: D

Rationale: All of these statements are true regarding the ventricles of the heart. The left ventricle does indeed pump oxygenated blood into the aorta, while the right ventricle pumps deoxygenated blood into the pulmonary trunk. Ventricles are indeed the discharging chambers of the heart, responsible for pumping blood out into the circulatory system. Therefore, as all the statements are accurate, the correct answer is 'All of the above.' Choices A, B, and C are all correct statements about the ventricles, making them incorrect answers in isolation.

Correct Answer: C

Rationale: Pluripotent stem cells are capable of developing into many different cell types, but they cannot form a complete organism. Totipotent stem cells have the ability to give rise to all cell types in an organism, including extraembryonic tissues, enabling them to form a complete organism. Multipotent stem cells can differentiate into a limited range of cell types. Hematopoietic stem cells specifically give rise to blood cells.

Correct Answer: B

Rationale: The correct answer is B, the Scapula. Flat bones, such as the scapula, are thin, flattened bones that provide protection to internal organs and serve as attachment points for muscles. The other choices, femur, humerus, and tibia, are examples of long bones, which are characterized by their elongated structure and are primarily involved in supporting weight and facilitating movement.

Correct Answer: B

Rationale: Skeletal muscle is the correct answer as it is responsible for moving the skeleton. Skeletal muscles are under voluntary control, meaning they can be consciously controlled by the individual. Cardiac muscle (Choice A) is found in the heart and is responsible for pumping blood, not moving the skeleton. Smooth muscle (Choice C) is found in internal organs and is responsible for involuntary movements like digestion. Voluntary muscle (Choice D) is not a specific type of muscle; it refers to muscles that can be consciously controlled, which includes skeletal muscles.

Correct Answer: B

Rationale: Crossing over occurs during Prophase I of meiosis. This stage is specifically associated with genetic recombination, where homologous chromosomes exchange genetic material. This process contributes to genetic diversity by creating new combinations of alleles. Choices A, C, and D are incorrect. In mitosis, crossing over does not occur as it involves the separation of replicated chromosomes. Meiosis Prophase II is focused on the reformation of nuclei and does not involve crossing over. Interphase is a stage where the cell prepares for division and is not associated with crossing over.