Free SAT Biology Cellular Structure & Function Questions and Answers — Questions and Answers
Question 1: Which organelle is responsible for producing ATP in eukaryotic cells?
- Ribosome
- Chloroplast
- Nucleus
- Mitochondrion (Correct answer)
Correct answer: Mitochondrion
Mitochondria are known as the 'powerhouses' of eukaryotic cells because they are the primary sites where cellular respiration occurs. This metabolic process generates adenosine triphosphate (ATP), which is the main energy currency used by the cell for various functions.
Question 2: What is the function of the rough endoplasmic reticulum?
- Lipid synthesis
- Protein synthesis and transport (Correct answer)
- DNA replication
- Detoxification
Correct answer: Protein synthesis and transport
The rough endoplasmic reticulum (RER) is characterized by the presence of ribosomes on its surface. These ribosomes are responsible for synthesizing proteins, particularly those destined for secretion, insertion into membranes, or delivery to other organelles. The RER then aids in the folding, modification, and transport of these proteins.
Question 3: Which structure controls the movement of substances into and out of the cell?
- Cytoplasm
- Nucleus
- Plasma membrane (Correct answer)
- Cell wall
Correct answer: Plasma membrane
The plasma membrane, also known as the cell membrane, is a selectively permeable barrier that surrounds the cell. Its primary function is to regulate the passage of molecules, ions, and other substances into and out of the cell. This control is crucial for maintaining cellular homeostasis and ensuring the cell's proper function and survival.
Question 4: Which organelle is found only in plant cells and is responsible for photosynthesis?
- Mitochondrion
- Chloroplast (Correct answer)
- Golgi apparatus
- Ribosome
Correct answer: Chloroplast
Chloroplasts are unique organelles found exclusively in plant cells and some algae. They contain chlorophyll and are the sites where photosynthesis occurs, converting light energy into chemical energy in the form of glucose. This process is fundamental for the energy production of plants and, indirectly, for most life on Earth.
Question 5: What is the primary function of ribosomes?
- Protein synthesis (Correct answer)
- Energy production
- Transport
- Cell division
Correct answer: Protein synthesis
Ribosomes are cellular organelles responsible for protein synthesis, a process also known as translation. They read the genetic information encoded in messenger RNA (mRNA) and use it to assemble amino acids into specific protein sequences. This function is vital for all cellular activities, as proteins perform a vast array of functions within the cell and organism.
Question 6: What is the role of lysosomes in the cell?
- Energy production
- Photosynthesis
- Protein modification
- Digestion of cellular waste (Correct answer)
Correct answer: Digestion of cellular waste
Lysosomes are membrane-bound organelles containing powerful digestive enzymes. Their primary role is to break down waste materials, cellular debris, and foreign invaders like bacteria and viruses. This process of intracellular digestion helps recycle cellular components and protects the cell from harmful substances, maintaining cellular health.
Question 7: Which cellular component is responsible for modifying, sorting, and packaging proteins?
- Endoplasmic reticulum
- Golgi apparatus (Correct answer)
- Cytoskeleton
- Peroxisome
Correct answer: Golgi apparatus
The Golgi apparatus, also known as the Golgi complex or Golgi body, is an organelle responsible for modifying, sorting, and packaging proteins and lipids synthesized in the endoplasmic reticulum. It acts like a cellular post office, directing these molecules to their correct destinations within or outside the cell. This function is crucial for cellular secretion and membrane synthesis.
Question 8: Which part of the cell contains genetic material?
- Nucleus (Correct answer)
- Cytoplasm
- Endoplasmic reticulum
- Cell membrane
Correct answer: Nucleus
In eukaryotic cells, the nucleus is a membrane-bound organelle that houses the cell's genetic material, primarily DNA, organized into chromosomes. It controls the cell's growth, metabolism, and reproduction by regulating gene expression. The nucleus is essentially the control center of the cell, directing its activities.
Question 9: What component of the cytoskeleton helps maintain cell shape and assists in movement?
- Lysosome
- Microtubules (Correct answer)
- Vacuole
- Ribosome
Correct answer: Microtubules
Microtubules are hollow cylinders made of tubulin protein that are part of the cytoskeleton. They play crucial roles in maintaining cell shape, providing structural support, and facilitating intracellular transport. They are also essential components of cilia, flagella, and the mitotic spindle, which is involved in cell division.
Free SAT Biology Cellular Structure & Function Questions and Answers
Which organelle is responsible for producing ATP in eukaryotic cells?