Correct Answer: D

Rationale: Muscle tissues require quick bursts of energy for activities such as contraction and relaxation. Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP through cellular respiration. Therefore, muscle cells would require higher amounts of mitochondria to meet their energy demands. Ribosomes are involved in protein synthesis and are not directly related to energy production. Chloroplasts are found in plant cells and are responsible for photosynthesis, not in animal muscle cells. Vacuoles are primarily involved in storage, maintaining turgor pressure, and digestion, but they are not the main organelles involved in energy production.

Correct Answer: C

Rationale: The pineal gland is correctly located at the center of the brain, between the two hemispheres. It is a small endocrine gland often referred to as the 'third eye' due to its unique location. Choices A, B, and D are incorrect as the pineal gland is not situated below the larynx, above the kidney, or at the base of the brain.

Correct Answer: A

Rationale: The correct answer is A: mRNA (messenger RNA). mRNA contains the genetic code or instructions for making a protein. During protein synthesis, mRNA carries the genetic information from DNA in the cell nucleus to the ribosomes, where proteins are synthesized. The sequence of nucleotides in mRNA corresponds to the sequence of amino acids that will be used to build the protein. Choice B, tRNA (transfer RNA), is involved in carrying amino acids to the ribosome during protein synthesis but does not contain the code for making a protein. Choice C, rRNA (ribosomal RNA), is a component of ribosomes where protein synthesis occurs but does not contain the specific code for making a protein. Choice D, DNA polymerase, is an enzyme involved in DNA replication, not in directly coding for protein synthesis.

Correct Answer: C

Rationale: The law of independent assortment describes how alleles of different genes segregate independently during gamete formation. This means that different gene pairs are passed on to offspring separately from one another, allowing for various combinations of traits. Gregor Mendel discovered this law, along with the law of segregation and the law of dominance, through his experiments with pea plants. The law of segregation (choice A) refers to how alleles of a gene separate during gamete formation, while the law of dominance (choice B) states that one allele can mask the presence of another in a heterozygous individual. The 'law of predictive traits' (choice D) is not a recognized Mendelian law and does not accurately describe the principles of genetic inheritance.

Correct Answer: A

Rationale: A cell placed in a hypertonic solution has a higher solute concentration outside the cell compared to inside. This creates a concentration gradient that causes water to move out of the cell through osmosis to equalize the concentrations on both sides. As a result, the cell will shrink or undergo plasmolysis, as water is pulled out of the cell. Choice B is incorrect because a hypertonic solution causes water to move out of the cell, leading to shrinkage rather than swelling. Choice C is incorrect as a hypertonic solution results in a concentration gradient that leads to water leaving the cell, causing it to shrink. Choice D is incorrect because pH is not directly affected by being placed in a hypertonic solution; the change in solute concentration primarily impacts water movement.