The question asks to identify the scientist credited with the discovery of the live cell. This requires knowledge of the history of cell biology and the contributions of key scientists.
Anton Van Leeuwenhoek, a Dutch scientist, is widely recognized for his pioneering work in microscopy. In the 17th century, using his self-made single-lens microscopes, he was the first to observe and accurately describe various microscopic life forms, which he called "animalcules." These included bacteria, protozoa, sperm cells, and red blood cells. His detailed observations of these moving, living organisms marked the discovery of the live cell.
B) Anton Von Leeuwenhoek — He is credited with the discovery of the live cell (e.g., bacteria, protozoa) using his powerful self-made microscopes in the 17th century.
The question asks to identify a characteristic feature of prokaryotic cells. We need to recall the fundamental differences between prokaryotic and eukaryotic cells, particularly regarding their internal structures.
C) Presence of mesosome. Mesosomes are characteristic invaginations of the plasma membrane in prokaryotic cells, particularly bacteria, and are associated with various cellular functions like respiration and DNA replication.
The question asks about the primary function of plasmodesmata in plant cells. To answer this, we need to recall the structure and role of plasmodesmata in intercellular communication in plants.
C) Connecting cytoplasm of adjacent cells. Plasmodesmata are crucial for intercellular communication and transport in plants, forming cytoplasmic bridges between neighboring cells.
The question asks to identify the cell organelle known as the "powerhouse of the cell." This is a fundamental concept in cell biology, referring to the organelle responsible for generating most of the cell's supply of adenosine triphosphate (ATP), which is used as a source of chemical energy.
C) Mitochondrion
Mitochondria are often called the "powerhouses of the cell" because they are the sites of cellular respiration. During cellular respiration, glucose and other fuel molecules are broken down in the presence of oxygen to produce ATP (adenosine triphosphate), which is the main energy currency of the cell. This process provides the energy needed for various cellular activities, such as muscle contraction, nerve impulse transmission, and synthesis of macromolecules.
The question asks to identify the correct statements regarding the general differences between plant and animal cells. We need to evaluate each statement based on our knowledge of cell biology.
C) 1 and 3 only
Statements 1 and 3 are correct descriptions of the differences between plant and animal cells.
The question asks to identify the scientists who proposed the fluid mosaic model of the plasma membrane. This requires knowledge of key historical contributions to cell biology.
Correct Option: B) Singer and Nicolson. In 1972, S.J. Singer and G.L. Nicolson proposed the fluid mosaic model, which is the most widely accepted model for the structure of the plasma membrane. This model describes the plasma membrane as a mosaic of protein molecules floating in a fluid bilayer of phospholipids.