What determines the magnitude of the frictional force acting on a book sliding across a table?

Correct Answer: C

Rationale: The magnitude of the frictional force acting on the book sliding across a table is determined by both the mass of the book and the normal force from the table. Frictional force is proportional to the normal force (which is influenced by the weight of the book, i.e., its mass) and is affected by the surfaces in contact and other friction-related factors. Therefore, both the mass of the book and the normal force from the table are essential in determining the frictional force experienced by the book during its sliding motion. Choices A, B, and D are incorrect because friction is a result of the interaction between the surfaces and is influenced by both the mass of the object and the normal force acting on it.

Correct Answer: A

Rationale: In the sentence 'He gave his mother a bouquet of flowers,' the indirect object is 'his mother' because she is the recipient of the action of giving. The direct object is 'a bouquet of flowers' because it is the thing being given. The verb 'gave' is the action being performed. Choice B, 'bouquet,' is incorrect as it is the direct object, not the indirect object. Choice C, 'flowers,' is incorrect as it is part of the direct object phrase. Choice D, 'gave,' is incorrect as it is the verb indicating the action, not an object.

Correct Answer: D

Rationale: A) Directional selection is a recognized mode of natural selection where one extreme trait value on a spectrum is favored over others, leading to a shift in the average trait value over time. B) Disruptive selection is a recognized mode of natural selection where both extreme trait values on a spectrum are favored over the average trait value, potentially causing the population to split into distinct groups. C) Stabilizing selection is a recognized mode of natural selection favoring the average trait value on a spectrum over extreme values, resulting in reduced genetic diversity. D) Sexual selection differs from traditional natural selection modes as it involves mate choice and competition for mates, not direct selection pressure on traits affecting survival and reproduction in the environment. Sexual selection can drive the evolution of traits enhancing an individual's attractiveness for mating purposes.

Correct Answer: B

Rationale: The liver is the largest internal organ in the human body and is responsible for detoxification, metabolism, storage of nutrients, and various other essential functions. It plays a critical role in maintaining overall health by processing nutrients, filtering blood, and detoxifying harmful substances. While the skin is the largest organ by surface area, the liver is the largest internal organ and is crucial for various physiological processes. The heart is responsible for pumping blood, the lungs for respiration, and the skin for protection and temperature regulation, but they do not perform the functions specified in the question.

Correct Answer: A

Rationale: The three main types of muscle tissue in the human body are smooth muscle (involuntary), cardiac muscle (involuntary), and voluntary skeletal muscle. Smooth muscle is found in the walls of hollow organs, cardiac muscle is found in the heart, and skeletal muscle is attached to bones and is under voluntary control. Option A correctly identifies these three main types of muscle tissue in the human body. Choice B is incorrect because it lists skeletal muscle as involuntary, which is not accurate. Choice C is incorrect because it lists voluntary smooth muscle, which does not exist as smooth muscle is involuntary. Choice D is incorrect because it uses terms like striated, non-striated, and epithelial, which are not the main types of muscle tissue but rather descriptions related to muscle characteristics and location.