Correct Answer: A

Rationale: Statement A is correct. The biosphere refers to the part of the Earth where life exists, including the land, water bodies, and atmosphere. It is the zone where living organisms and ecosystems exist. Statement B is incorrect because the biosphere covers various ecosystems on Earth but does not encompass the entire surface of the planet. The biosphere includes regions such as the lithosphere (land), hydrosphere (water bodies), and atmosphere, but not every part of the Earth's surface. Therefore, option C, stating both A and B are correct, is inaccurate. The correct answer is option A, as it accurately defines the biosphere.

Correct Answer: B

Rationale: The correct answer is B: Smooth, skeletal, cardiac. Smooth muscle is found in organs like the stomach and is involuntarily controlled. Skeletal muscle is found in voluntary muscles, like the bicep or quadriceps. Cardiac muscle is found only in the heart walls and works involuntarily to make the heart beat and pump blood. Choices A, C, and D are incorrect because they do not represent the three types of muscle tissue.

Correct Answer: C

Rationale: The correct arrangement seen in the plasma membrane is proteins embedded in the lipid bilayer. The plasma membrane is composed of a lipid bilayer with embedded proteins. These proteins perform various functions such as transport, signaling, and structural support within the cell membrane. This arrangement allows for the selective permeability of the membrane and facilitates communication between the cell and its environment. Choices A, B, and D are incorrect because the primary arrangement in the plasma membrane involves proteins being embedded in the lipid bilayer, not lipids with embedded proteins, an outer and inner lipid layer, or altering protein and lipid layers.

Correct Answer: A

Rationale: A hypothesis is a statement or explanation of certain events or phenomena based on observations and prior knowledge. It is a testable prediction that guides the scientific investigation process. By formulating a hypothesis, scientists can make predictions and design experiments to gather data and test the validity of the hypothesis. Observations (choice B) involve gathering information through the senses. Experiments (choice C) are procedures carried out to support or refute a hypothesis. Conclusions (choice D) are deductions made based on the results of experiments and observations, but they are not the initial statement or explanation of events or happenings.

Correct Answer: D

Rationale: The correct answer is D, 'More than one of the above is true.' Optical microscopy utilizes visible light (Choice B) and often involves the use of dyes for samples (Choice C). Using dyes helps enhance contrast, making it easier to visualize the structures being observed. Choice A is incorrect as optical microscopy does not utilize scanning electrons, but rather visible light.