General Biology Reviewer

The double-membrane structure that contains pores for regulating the exchange of materials between the nucleus and cytoplasm is called:

• Nuclear envelope

• Endoplasmic reticulum

• Nucleolus

• Cytoskeleton

Which type of endoplasmic reticulum is studded with ribosomes and plays a major role in protein synthesis?

• Rough ER

• Smooth ER

• Golgi ER

• Secretory ER

In plant cells, which organelle stores water, ions, and waste products, and helps maintain turgor pressure?

• Central vacuole

• Lysosome

• Peroxisome

• Mitochondrion

The organelle that modifies, sorts, and packages proteins for secretion or delivery to other organelles is the:

• Lysosome

• Golgi apparatus

• Nucleolus

• Chloroplast

The mitochondrion is often called the “powerhouse of the cell.” Which specific process occurs here that justifies this nickname, and why is it essential for the cell’s survival?

• Fermentation, because it releases lactic acid for muscle function

• Photosynthesis, because it produces glucose for energy storage

• Cellular respiration, because it generates ATP used in energy-requiring processes

• Diffusion, because it moves nutrients across membranes

The smooth endoplasmic reticulum has no ribosomes attached to its surface. How does this structural feature relate to its primary function?

• It allows the SER to store water efficiently

• It enables the SER to produce lipids and detoxify harmful substances

• It helps the SER attach to the cytoskeleton

• It improves protein translation efficiency

A cell that specializes in producing large amounts of digestive enzymes would have an abundance of which organelles, and why?

• Lysosomes and mitochondria, for breaking down molecules and providing energy

• Golgi apparatus and lysosomes, for processing and storing enzymes

• Rough ER and Golgi apparatus, for synthesizing and packaging enzymes

• Smooth ER and chloroplasts, for detoxification and photosynthesis

The nucleolus is not surrounded by a membrane, yet it is considered a functional part of the nucleus. What is its main role in the cell?

• Producing ribosomal RNA and assembling ribosome subunits

• Storing genetic information for protein synthesis

• Controlling cell division

• Transporting proteins into the cytoplasm

In eukaryotic cells, what advantage does compartmentalization of functions into membrane-bound organelles provide?

• It prevents waste buildup in the cell

• It allows simultaneous specialized biochemical processes without interference

• It reduces the need for cellular energy

• It limits the number of chemical reactions

Which structural difference between mitochondria and chloroplasts reflects their specific roles in the cell?

• Mitochondria have a single membrane; chloroplasts have a double membrane

• Mitochondria contain cristae for respiration; chloroplasts contain thylakoids for photosynthesis

• Mitochondria contain DNA; chloroplasts do not

• Mitochondria lack ribosomes; chloroplasts have ribosomes