When suspecting an ovarian cyst on the basis of abdominal pain, what other causes need to be ruled out due to the severity of the condition? Select all that apply.

Correct Answer: A,B,C

Rationale: The correct answer is A, B, and C. A: Ectopic pregnancy can present similarly to an ovarian cyst with abdominal pain. It is a life-threatening emergency due to the risk of rupture. B: Inflamed appendix can mimic symptoms of an ovarian cyst, such as lower abdominal pain. Appendicitis can lead to serious complications without prompt treatment. C: Ovarian torsion can cause sudden, severe abdominal pain similar to that of an ovarian cyst. It requires immediate medical attention to prevent ovarian damage or necrosis. D: Submucosal fibroid is a benign growth in the uterus and would not typically cause symptoms that mimic an ovarian cyst.

Correct Answer: C

Rationale: The correct answer is C: Prophase I in females. Prophase I is the longest phase in meiosis due to the process of genetic recombination and crossing over. This phase involves pairing of homologous chromosomes, exchange of genetic material, and formation of chiasmata. These complex processes contribute to the extended duration of Prophase I. Incorrect choices: A: Anaphase I in males - Anaphase I is a relatively short phase where homologous chromosomes separate. B: Prophase II in males - Prophase II is shorter than Prophase I as it involves the formation of new spindles and nuclear envelope breakdown. D: Anaphase II in females - Anaphase II is also a short phase where sister chromatids separate.

Correct Answer: B

Rationale: The correct answer is B: Osteoclasts. Osteoclasts are bone cells responsible for breaking down the bone matrix through a process called bone resorption. They secrete enzymes and acids that dissolve the mineralized matrix, allowing for bone remodeling and repair. Osteocytes (A) are mature bone cells that help maintain bone tissue. Osteoblasts (C) are responsible for bone formation by synthesizing new bone matrix. Osteoprogenitor cells (D) are undifferentiated cells that can differentiate into osteoblasts. Therefore, the correct answer is B as osteoclasts specifically break down the bone matrix.

Correct Answer: A

Rationale: The correct answer is A: 2-3°C below the normal body temperature. Testicles need to be slightly cooler than the body's normal temperature for optimal functioning. This slight decrease in temperature helps in maintaining the viability of sperm production. Choices B, C, and D are incorrect because a greater deviation from the body's normal temperature would be detrimental to sperm production. B: 4-5°C is too much of a decrease, while C: 33-36°C and D: 31-34°C are higher than the normal body temperature, which would hinder sperm production.

Correct Answer: A

Rationale: The correct answer is A: Four-cell stage. Dichorionic-diamniotic twins occur when the embryo splits into two separate embryos very early in development, typically at the four-cell stage. At this stage, each embryo will have its own chorion and amnion, leading to separate placentas and amniotic sacs. Choices B, C, and D occur later in development and do not result in the formation of two separate embryos with their own chorion and amnion, making them incorrect for the scenario of dichorionic-diamniotic twins.