Biology Cell Structure & Function 1 — Questions and Answers
Question 1: What is the function of the cell membrane?
- It produces energy for the cell.
- It controls what enters and leaves the cell (Correct answer)
- It stores genetic information.
- It synthesizes proteins.
Correct answer: It controls what enters and leaves the cell
The cell membrane, composed of a lipid bilayer, acts as a selective barrier that encloses the cell's contents. Its primary function is to regulate the passage of substances, such as nutrients and waste products, into and out of the cell. This selective permeability is vital for maintaining the cell's internal environment and protecting it from external changes, ensuring proper cellular function and survival.
Question 2: What is the main function of mitochondria?
- Protein synthesis.
- Energy production through ATP (Correct answer)
- DNA storage.
- Lipid synthesis.
Correct answer: Energy production through ATP
Mitochondria are often called the 'powerhouses' of the cell because their main function is cellular respiration. During this process, they convert glucose and oxygen into adenosine triphosphate (ATP), which is the primary energy currency used by the cell. This ATP fuels various metabolic activities, making mitochondria essential for virtually all cellular functions and the overall survival of the organism.
Question 3: What is the function of ribosomes?
- Energy storage.
- Protein synthesis (Correct answer)
- Waste removal.
- Transporting materials.
Correct answer: Protein synthesis
Ribosomes are essential cellular organelles responsible for translating messenger RNA (mRNA) into proteins. They read the genetic code carried by mRNA and assemble amino acids in the correct sequence to form functional proteins. These proteins are crucial for virtually all cellular processes, structures, and enzymatic reactions, making protein synthesis a fundamental activity for life.
Question 4: What is the role of the nucleus in a cell?
- Producing energy.
- Housing DNA and coordinating cellular activities (Correct answer)
- Breaking down waste.
- Moving the cell.
Correct answer: Housing DNA and coordinating cellular activities
The nucleus serves as the control center of the eukaryotic cell. Its primary role is to house the cell's genetic material (DNA) organized into chromosomes, protecting it from damage. Furthermore, it coordinates all cellular activities by regulating gene expression, thereby controlling protein synthesis, cell division, and overall cellular function.
Question 5: What structure is responsible for photosynthesis in plant cells?
- Mitochondria.
- Chloroplasts (Correct answer)
- Vacuoles.
- Endoplasmic reticulum.
Correct answer: Chloroplasts
Chloroplasts are specialized organelles found in plant cells and some other eukaryotic organisms. They contain chlorophyll, a pigment that captures light energy, and are the site where photosynthesis takes place. This vital process converts light energy into chemical energy in the form of glucose, providing food for the plant and ultimately supporting most life on Earth.
Question 6: What is the function of the Golgi apparatus?
- Generating ATP.
- Modifying and packaging proteins and lipids (Correct answer)
- Producing ribosomes.
- Breaking down macromolecules.
Correct answer: Modifying and packaging proteins and lipids
The Golgi apparatus, or Golgi complex, acts like a cellular post office. Its main function is to further process, sort, and package proteins and lipids that have been synthesized in the endoplasmic reticulum. These modified molecules are then directed to their correct destinations, either within the cell or for secretion outside the cell, ensuring proper cellular organization and function.
Question 7: What is the role of lysosomes?
- Storing nutrients.
- Digesting waste and cellular debris (Correct answer)
- Transporting proteins.
- Maintaining cell shape.
Correct answer: Digesting waste and cellular debris
Lysosomes are membrane-bound organelles containing powerful digestive enzymes. Their primary role is to break down waste materials, cellular debris, foreign invaders like bacteria, and worn-out organelles. This process, called autophagy, is crucial for recycling cellular components, maintaining cell health, and protecting the cell from harmful substances.
Question 8: Which organelle helps maintain cell shape and supports intracellular transport?
- Cytoplasm.
- Cytoskeleton (Correct answer)
- Centrioles.
- Peroxisomes.
Correct answer: Cytoskeleton
The cytoskeleton is a dynamic network of protein filaments and tubules found in the cytoplasm of many cells. It provides crucial structural support, helping the cell maintain its shape and resist mechanical stress. Additionally, it plays a vital role in cell movement, cell division, and the intracellular transport of organelles and vesicles, ensuring proper cellular organization and function.
Question 9: What is the main function of the endoplasmic reticulum (ER)?
- Breaking down toxins.
- Synthesizing proteins and lipids (Correct answer)
- Producing ATP.
- Housing genetic material.
Correct answer: Synthesizing proteins and lipids
The endoplasmic reticulum (ER) is a vast network of membranes within the cytoplasm. The rough ER, studded with ribosomes, is primarily involved in synthesizing and folding proteins destined for secretion or insertion into membranes. The smooth ER, lacking ribosomes, is crucial for lipid synthesis, detoxification of drugs and poisons, and calcium storage, making the ER vital for diverse cellular functions.
Biology Cell Structure & Function 1
What is the function of the cell membrane?