1. What is the basic unit of life?
Answer:
Explanation:
The cell is the basic unit of life. All living organisms are made up of cells, which are the smallest units that can carry out all the processes necessary for life.
2. Which organelle is known as the powerhouse of the cell?
Answer:
Explanation:
Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy.
3. What is the function of ribosomes in a cell?
Answer:
Explanation:
Ribosomes are the sites in a cell where proteins are synthesized. They translate messenger RNA (mRNA) into polypeptide chains to form proteins.
4. What type of cells have a defined nucleus?
Answer:
Explanation:
Eukaryotic cells have a defined nucleus enclosed in a nuclear membrane, unlike prokaryotic cells, which do not have a defined nucleus.
5. Which of the following is a feature of plant cells but not animal cells?
Answer:
Explanation:
Plant cells have a rigid cell wall made up of cellulose that provides structural support. Animal cells do not have a cell wall.
6. The fluid mosaic model is used to describe the structure of which cell component?
Answer:
Explanation:
The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components, including phospholipids, cholesterol, proteins, and carbohydrates, that give the membrane a fluid character.
7. Which organelle is responsible for photosynthesis in plant cells?
Answer:
Explanation:
Chloroplasts are the organelles in plant cells where photosynthesis occurs. They contain chlorophyll, which captures light energy to convert carbon dioxide and water into glucose and oxygen.
8. What is the process of programmed cell death called?
Answer:
Explanation:
Apoptosis is the process of programmed cell death, which is a normal part of an organism's growth and development. It is a controlled process that eliminates unnecessary or damaged cells.
9. In cell biology, what is osmosis primarily concerned with?
Answer:
Explanation:
Osmosis is the process by which water molecules move across a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.
10. Which structure in the cell serves as the site for protein sorting and packaging?
Answer:
Explanation:
The Golgi apparatus is involved in the sorting and packaging of proteins for transport. It modifies proteins and lipids made by the endoplasmic reticulum and prepares them for export outside the cell or to other locations within the cell.
11. Which cellular process involves the division of the cytoplasm to form two separate daughter cells?
Answer:
Explanation:
Cytokinesis is the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells. It usually occurs at the end of mitosis or meiosis.
12. What is the primary function of the nucleolus in the cell?
Answer:
Explanation:
The nucleolus is the site within the nucleus that is responsible for assembling ribosomal subunits in eukaryotic cells. It is involved in the processing and assembly of rRNA into ribosomes.
13. Which type of RNA carries the genetic information from DNA to the ribosomes?
Answer:
Explanation:
Messenger RNA (mRNA) carries the genetic information from DNA in the nucleus to the ribosomes in the cytoplasm, where protein synthesis occurs.
14. What is the primary function of lysosomes in the cell?
Answer:
Explanation:
Lysosomes contain digestive enzymes and are involved in the breakdown of macromolecules, old cell parts, and microorganisms.
15. Which organelle is responsible for lipid synthesis and detoxification?
Answer:
Explanation:
The Smooth Endoplasmic Reticulum (SER) is involved in lipid synthesis, carbohydrate metabolism, and detoxification of drugs and poisons.
16. What is the name of the process by which cells engulf particles to bring them into the cell?
Answer:
Explanation:
Endocytosis is the process by which cells internalize particles, molecules, and even small cells through the invagination of the cell membrane.
17. In which phase of mitosis do chromosomes line up at the cell's equatorial plate?
Answer:
Explanation:
During metaphase, the chromosomes align at the metaphase plate (equatorial plate) of the cell, preparing for segregation into the daughter cells.
18. Which of the following is NOT a component of the cell theory?
Answer:
Explanation:
Cell theory states that all living organisms are composed of cells, the cell is the basic unit of life, and all cells come from pre-existing cells. It does not specify the mode of cell reproduction.
19. What is the function of centrioles in a cell?
Answer:
Explanation:
Centrioles play a key role in cell division in animal cells. They help in organizing the mitotic spindle, which is essential for separating chromosomes during cell division.
20. Which structure is primarily involved in the synthesis and transport of proteins in a cell?
Answer:
Explanation:
The Endoplasmic Reticulum (ER) is involved in the synthesis of proteins (Rough ER) and lipids (Smooth ER), and in their transport throughout the cell.
21. Which part of the cell is responsible for breaking down and recycling cellular waste?
Answer:
Explanation:
Lysosomes are membrane-bound organelles that contain enzymes for breaking down various types of cellular waste and debris. They are crucial for the recycling of cellular components.
22. Which type of cell junctions provide mechanical stability and are found in tissues subject to stretching or bending?
Answer:
Explanation:
Desmosomes are specialized structures in cell membranes that provide mechanical stability to tissues. They are particularly important in tissues that undergo a lot of stretching and bending, like skin and heart muscle.
23. The process by which plants convert carbon dioxide and water into glucose and oxygen using sunlight is known as:
Answer:
Explanation:
Photosynthesis is the process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organism's activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water.
24. What is the primary purpose of cellular respiration?
Answer:
Explanation:
Cellular respiration is the process by which cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and release waste products.
25. Which cellular organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
Answer:
Explanation:
The Smooth Endoplasmic Reticulum (SER) is involved in the synthesis of lipids, including oils, phospholipids, and steroids. It also helps in detoxification and carbohydrate metabolism.
26. What are the main stages of the cell cycle?
Answer:
Explanation:
The cell cycle is divided into four main stages: G1 (first gap), S (synthesis of DNA), G2 (second gap), and M (mitosis). These stages ensure that cells grow, replicate their DNA accurately, and divide properly.
27. Which process in eukaryotic cell division results in two genetically identical daughter cells?
Answer:
Explanation:
Mitosis is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei, resulting in two genetically identical daughter cells.
28. In eukaryotic cells, where does the Krebs cycle (Citric Acid Cycle) take place?
Answer:
Explanation:
The Krebs cycle, also known as the Citric Acid Cycle, takes place in the mitochondrial matrix of eukaryotic cells. It is a key part of cellular respiration.
29. What is the primary role of the Golgi apparatus in a cell?
Answer:
Explanation:
The Golgi apparatus modifies, sorts, and packages proteins and lipids that are synthesized in the cell. It is involved in the trafficking of lipids and proteins to their destinations.
30. The process by which a cell engulfs a solid particle to form an internal compartment known as a phagosome is called:
Answer:
Explanation:
Phagocytosis is a process where a cell engulfs a solid particle to form an internal compartment known as a phagosome. It is a form of endocytosis and is often used by cells to ingest bacteria or other large particles.
31. Which cellular structure is responsible for assembling amino acids into proteins?
Answer:
Explanation:
Ribosomes are the cellular structures responsible for protein synthesis. They translate mRNA into polypeptide chains, assembling amino acids into proteins according to the genetic instructions carried by the mRNA.
32. What is the primary role of vacuoles in plant cells?
Answer:
Explanation:
Vacuoles are large, membrane-bound structures within plant cells that serve various functions, most importantly the storage of water, nutrients, and waste products.
33. The semi-permeable membrane that surrounds the cell and controls the movement of substances in and out of the cell is called:
Answer:
Explanation:
The plasma membrane, also known as the cell membrane, is a semi-permeable membrane that surrounds the cell, controlling the movement of substances in and out of the cell, thus maintaining the internal environment of the cell.
34. What is the function of microtubules in a cell?
Answer:
Explanation:
Microtubules are a component of the cytoskeleton in eukaryotic cells. They provide structural support and are also involved in various types of cell movement, including cell division and intracellular transport.
35. In which organelle does the process of oxidative phosphorylation occur?
Answer:
Explanation:
Oxidative phosphorylation occurs in the mitochondria. It is the process by which energy produced from carbohydrates and fats is transferred to ATP during cellular respiration.
36. What is the main function of the nucleolus within the nucleus?
Answer:
Explanation:
The nucleolus is a region within the nucleus that is responsible for producing and assembling ribosome subunits from proteins and ribosomal RNA (rRNA).
37. Which cellular process is responsible for the production of carbon dioxide and water as waste products?
Answer:
Explanation:
Cellular respiration is a metabolic process in cells that converts biochemical energy from nutrients into ATP, and releases waste products, including carbon dioxide and water.
38. What is the term used to describe the network of proteins that gives a cell its shape and helps it move?
Answer:
Explanation:
The cytoskeleton is a network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence. It is also involved in intracellular transport and cellular movement.
39. In cell biology, which process describes the replication of DNA?
Answer:
Explanation:
DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. It is an essential process for cell division, growth, and reproduction.
40. Which type of cellular transport requires energy to move substances against their concentration gradient?
Answer:
Explanation:
Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. This process requires energy, usually in the form of ATP.
41. Which process is used by cells to capture energy from sunlight and convert it into chemical energy?
Answer:
Explanation:
Photosynthesis is the process used by plants and other autotrophs to capture light energy from the sun and convert it into chemical energy in the form of glucose. This process involves the transformation of water and carbon dioxide into glucose and oxygen.
42. Which organelle is responsible for the detoxification of harmful substances in liver cells?
Answer:
Explanation:
The Smooth Endoplasmic Reticulum (SER) in liver cells is involved in the detoxification of various harmful substances. It plays a significant role in metabolizing drugs and toxins.
43. In which phase of cell division do chromosomes first become visible under a light microscope?
Answer:
Explanation:
During prophase, the first phase of cell division, chromosomes condense and become visible under a light microscope. The nuclear membrane also starts to disintegrate in this phase.
44. What is the main difference between prokaryotic and eukaryotic cells?
Answer:
Explanation:
The main difference between prokaryotic and eukaryotic cells is that eukaryotic cells have membrane-bound organelles, including a nucleus, whereas prokaryotic cells do not.
45. What is the primary role of the cell wall in plant cells?
Answer:
Explanation:
The cell wall in plant cells is primarily responsible for providing structural support and protection. It is a rigid layer that surrounds the cell membrane and is composed mainly of cellulose.
46. Which cellular structure is involved in the process of translating mRNA into proteins?
Answer:
Explanation:
Ribosomes are responsible for translating mRNA into proteins. They read the sequence of mRNA and assemble the corresponding amino acids to form a protein.
47. The process by which cells release energy in the absence of oxygen is called:
Answer:
Explanation:
Anaerobic respiration is the process by which cells release energy from glucose in the absence of oxygen. This process is less efficient than aerobic respiration and results in the production of lactic acid or ethanol.
48. Which of the following best describes the function of the mitochondria?
Answer:
Explanation:
Mitochondria are known as the powerhouse of the cell because they are the site of cellular respiration. Here, energy stored in food is converted into ATP, which is used by the cell for energy.
49. In a eukaryotic cell, where does transcription occur?
Answer:
Explanation:
In eukaryotic cells, transcription, the process of copying DNA into RNA, occurs in the nucleus. The resulting mRNA is then transported to the cytoplasm where it is translated into protein.
50. What type of protein filaments make up the cytoskeleton of a cell?
Answer:
Explanation:
The cytoskeleton of a cell is made up of three types of protein filaments: microfilaments, intermediate filaments, and microtubules. These structures provide support and shape to the cell, and are involved in cell movement and transport within the cell.