Correct Answer: A

Rationale: A) Golgi apparatus: The Golgi apparatus is responsible for modifying, sorting, and packaging proteins into vesicles for secretion outside the cell or for use within the cell. It acts as a distribution and shipping department for the cell, ensuring proteins are properly processed and sent to their correct destinations like the extracellular space. Golgi apparatus is the correct answer because it directly handles the packaging and secretion of proteins. B) Mitochondria: Mitochondria are known as the powerhouse of the cell and are responsible for generating energy in the form of ATP through cellular respiration. They are not involved in packaging and secreting proteins into the extracellular space. C) Ribosomes: Ribosomes are responsible for protein synthesis, where they translate mRNA into proteins. They are not involved in packaging and secreting proteins into the extracellular space. D) Endoplasmic reticulum: The endoplasmic reticulum (ER) plays a role in protein synthesis and folding, but it is the rough ER specifically that is involved in synthesizing proteins that are then transported to the Golgi apparatus for further processing and packaging. The Golgi apparatus is primarily responsible for packaging and secreting proteins, making it the correct answer for this question.

Correct Answer: D

Rationale: Trypsin is the correct enzyme that breaks down proteins into amino acids. It is produced by the pancreas and released into the small intestine to facilitate protein digestion. Pepsin is an enzyme from the stomach that also breaks down proteins, amylase targets carbohydrates, and lipase works on fats. In this context, since the question specifies the pancreas and small intestine, the correct answer is Trypsin as it is the pancreatic enzyme responsible for protein breakdown in the small intestine.

Correct Answer: C

Rationale: Friction is a force that opposes motion. When two surfaces are in contact, friction acts in the opposite direction to the motion or the potential motion between the two surfaces. It resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction hinders or prevents motion rather than promoting it. Choices A, B, and D are incorrect as they suggest that friction increases, accelerates, or creates motion, which is inaccurate. The correct definition of friction is that it opposes motion, making choice C the most appropriate option.

Correct Answer: B

Rationale: A) Punctuated equilibrium refers to rapid bursts of evolution followed by long periods of stability, rather than gradual change over time in response to environmental pressures. B) Gradualism is the process by which species evolve through slow and continuous changes over time in response to environmental pressures. This gradual change can lead to the development of new traits and adaptations. C) Founder effect is a type of genetic drift that occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not specifically describe the gradual change in a species over time. D) Adaptive radiation is the rapid diversification of a species into a variety of forms to exploit different ecological niches, but it does not specifically refer to the gradual change in response to environmental pressures. Therefore, the term that best describes the gradual change in a species over time in response to environmental pressures is 'Gradualism.'

Correct Answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. The rate-determining step involves the nucleophile attacking the electrophile, so the concentrations of both species will impact the reaction rate. Increasing the concentration of the nucleophile increases the frequency of nucleophilic attacks, while increasing the concentration of the electrophile provides more opportunities for the nucleophile to react. Therefore, the correct answer is that both the concentration of the nucleophile and the electrophile affect the rate of the SN2 reaction. Choices A, B, and C are incorrect as they do not consider the interplay between the nucleophile and the electrophile in determining the overall reaction rate in an SN2 mechanism.