What is the main difference between a nuclear reactor and a nuclear bomb?

Correct Answer: B

Rationale: The main difference between a nuclear reactor and a nuclear bomb is that reactors have controlled chain reactions, while bombs have uncontrolled chain reactions. Nuclear reactors are designed to sustain a controlled nuclear reaction to generate electricity. In contrast, nuclear bombs are designed to release a massive amount of energy in an uncontrolled chain reaction, resulting in an explosion. Choice A is incorrect because both reactors and bombs can use enriched uranium. Choice C is incorrect as nuclear reactors also generate electricity, not just bombs. Choice D is incorrect because both reactors and bombs may or may not use moderators, but the key distinction lies in the control of the chain reaction.

Correct Answer: C

Rationale: The purpose of genetic counseling is to provide information and support to individuals and families with genetic risks. Genetic counselors aim to explain the implications of genetic testing, discuss risks and options, and offer emotional and psychological support to help individuals make informed decisions regarding their genetic health. Choice A is incorrect because genetic counseling is not focused on treatment but rather on providing information and support. Choice B is incorrect as genetic counselors do not primarily diagnose genetic diseases in newborns but rather provide guidance and support based on existing diagnoses. Choice D is not the purpose of genetic counseling; genetic counselors do not collect DNA samples for research purposes but instead focus on assisting individuals and families in understanding and managing their genetic risks.

Correct Answer: A

Rationale: Rationale: - Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene). - Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle. - During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.

Correct Answer: C

Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the trachea during swallowing to prevent food and liquids from entering the airway. This action helps direct food and liquids into the esophagus, which leads to the stomach for digestion, while also protecting the respiratory system from potential blockages that could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as the epiglottis is not involved in storing bile, absorbing nutrients, or producing digestive enzymes. Understanding the role of the epiglottis in the swallowing process is crucial for maintaining proper respiratory and digestive functions.

Correct Answer: B

Rationale: The appendix is a small pouch attached to the large intestine and is part of the lymphatic system. Its main function is to produce immune cells, particularly lymphocytes, which play a crucial role in fighting infections and maintaining gut health. Therefore, the correct answer is B. The appendix does not serve to store waste products (option A), secrete digestive enzymes (option C), or regulate blood sugar levels (option D).