Lower jaw bone is called as

Correct Answer: B

Rationale: The lower jaw bone is known as the mandible. The mandible is the only movable bone in the skull, forming the lower jaw and holding the lower teeth in place. The maxilla (A) is the upper jaw bone. The temporal bone (C) is a bone that forms part of the skull, but it is not the lower jaw bone. Menton (D) is a landmark on the mandible, not the name of the bone itself. Therefore, the correct answer is B (Mandible) as it is specifically designated as the lower jaw bone.

Correct Answer: C

Rationale: The correct answer is C: Malunion. Malunion refers to a fracture that has healed in an unacceptable alignment. This occurs when the fractured bones do not align properly during the healing process, leading to deformity or functional impairment. Delayed union (A) is when a fracture takes longer than usual to heal. Crepitus (B) is a term used to describe a grating or crackling sound or sensation in a joint. Nonunion (D) is when a fracture fails to heal altogether. Malunion specifically addresses the issue of improper alignment post-fracture healing, making it the most appropriate choice in this scenario.

Correct Answer: D

Rationale: The correct answer is D: ejaculation occurs. When the penis is erect, semen is released from the male body through ejaculation. During sexual arousal, the muscles contract, pushing semen through the urethra and out of the body. Urination (choice A) is a separate process controlled by the bladder, not related to semen release. Evacuation (choice B) refers to bowel movements, not semen release. Excitement (choice C) is a psychological state and does not directly lead to semen leaving the body. Therefore, the correct answer is D as it accurately describes the physiological process of semen leaving the male body during ejaculation.

Correct Answer: C

Rationale: The correct answer is C: Iris stroma. The iris stroma contains melanocytes, which are responsible for producing the pigmented cells that determine eye color. These pigmented cells give the iris its color by absorbing and reflecting light. The ciliary epithelium (choice A) is not involved in determining eye color. The iris epithelium (choice B) is mainly responsible for controlling the size of the pupil, not for determining eye color. The corneal stroma (choice D) is a layer of the cornea that primarily provides structural support and transparency to the eye, but it does not play a role in determining eye color.

Correct Answer: D

Rationale: The correct answer is D: zygote. After fertilization, the sperm and egg unite to form a zygote, which is the initial cell of a new organism with a full set of chromosomes. A gamete (A) is a reproductive cell before fertilization, an embryo (B) is the early stage of development after the zygote, and a fetus (C) is the later stage of development in the womb. Therefore, the zygote is the correct term for the cell produced by fertilization.