Biology Test

Correct Answer: C

Rationale: The correct answer is C: Lysosomes. Lysosomes contain enzymes that break down waste materials and cellular debris within the cell, making them the cell's digestion center. Choice A, Chloroplasts, are responsible for photosynthesis. Choice B, Mitochondria, are the powerhouse of the cell, generating energy. Choice D, Ribosomes, are involved in protein synthesis. Therefore, Lysosomes are specifically known for their role in digestion within the cell.

Correct Answer: D

Rationale: The correct answer is D. Ice forms a lattice structure when it freezes, which makes it less dense than liquid water, allowing it to float. Choice A is incorrect because viscosity refers to a fluid's resistance to flow and is not related to ice floating. Choice B is incorrect as ice and liquid water have the same chemical composition (H2O). Choice C is incorrect because the high specific heat of water is not the reason why ice floats.

Correct Answer: B

Rationale: The smooth endoplasmic reticulum is the correct organelle responsible for the synthesis of lipids, including phospholipids, cholesterol, and steroid hormones. The rough endoplasmic reticulum is primarily involved in protein synthesis and processing, making choice A incorrect. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids for transportation, so it is not directly involved in lipid and steroid hormone synthesis, making choice C incorrect. Ribosomes are responsible for protein synthesis and are not involved in lipid or steroid hormone synthesis, making choice D incorrect.

Correct Answer: C

Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.

Correct Answer: B

Rationale: The correct answer is B, Mendel. Gregor Mendel is known as the father of genetics for his groundbreaking work with pea plants. He discovered the basic principles of heredity through his experiments, establishing the foundation of modern genetics. Choice A, Curie, is incorrect as Marie Curie was a physicist and chemist known for her pioneering research on radioactivity. Choice C, Hawking, is incorrect as Stephen Hawking was a theoretical physicist known for his work on black holes and cosmology. Choice D, Galileo, is incorrect as Galileo Galilei was an astronomer and physicist renowned for his contributions to the scientific revolution, particularly in astronomy.