Q: The existence of the plasma membrane was identified in the 1890s, and its chemical components were identified in 1915. the principal components identified at that time were these? Read this paragraph and choose the correct option from the provided answers: Fluid Mosaic Model The existence of the plasma membrane was identified in the 1890s, and its chemical components were identified in 1915. The principal components identified at that time were lipids and proteins. The first widely accepted model of the plasma membrane's structure was proposed in 1935 by Hugh Davson and James Danielli; it was based on the "railroad track" appearance of the plasma membrane in early electron micrographs. They theorized that the structure of the plasma membrane resembles a sandwich, with protein being analogous to the bread, and lipids being analogous to the filling. In the 1950s, advances in microscopy, notably transmission electron microscopy (TEM), allowed researchers to see that the core of the plasma membrane consisted of a double, rather than a single, layer. A new model that better explains both the microscopic observations and the function of that plasma membrane was proposed by S. Singer and Garth L. Nicolson in 1972. The explanation proposed by Singer and Nicolson is called the fluid mosaic model. The model has evolved somewhat over time, but it still best accounts for the structure and functions of the plasma membrane as we now understand them. The fluid mosaic model describes the structure of the plasma membrane as a mosaic of componentsincluding phospholipids, cholesterol, proteins, and carbohydratesthat gives the membrane a fluid character. Plasma membranes range from 5 to 10 nm in thickness. For comparison, human red blood cells, visible via light microscopy, are approximately 8 m wide, or approximately 1,000 times wider than a plasma membrane. The membrane does look a bit like a sandwich (Figure 5.2). Choices: - gasses and proteins - carbohydrates and proteins - lipids and carbohydrates - lipids and proteins A:
lipids and proteins

Q: What type of matter transmits light without scattering it? Read this paragraph and choose the correct option from the provided answers: Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it. Choices: - translucent - clean - bioluminescent - transparent A:
transparent

Q: Q: John dalton thought that what unit, which means "indivisible", could not be divided into smaller, simpler particles? Read this paragraph and choose the correct option from the provided answers: Scientists have long wanted to find the most basic building blocks of the universe. They asked, "what are the fundamental particles of matter that cannot be subdivided into smaller, simpler particles," and "what holds these particles together?" The quest for fundamental particles began thousands of years ago. Scientists thought they had finally found them when John Dalton discovered the atom in 1803 (see the timeline in Table below ). The word atom means "indivisible," and Dalton thought that the atom could not be divided into smaller, simpler particles. Choices: - electron - nucleus - neutron - atom A:
A: atom

Question: Q: What occurs when there is little to no rain in a period of time? Read this paragraph and choose the correct option from the provided answers: Choices: - pollution - hurricanes - floods - droughts A:
Answer: droughts

*Question*
Q: Skeletal, cardiac, and smooth are the three types of what cells and possess morphologies correlated with their functions? Read this paragraph and choose the correct option from the provided answers: 4.4 Muscle Tissue and Motion The three types of muscle cells are skeletal, cardiac, and smooth. Their morphologies match their specific functions in the body. Skeletal muscle is voluntary and responds to conscious stimuli. The cells are striated and multinucleated appearing as long, unbranched cylinders. Cardiac muscle is involuntary and found only in the heart. Each cell is striated with a single nucleus and they attach to one another to form long fibers. Cells are attached to one another at intercalated disks. The cells are interconnected physically and electrochemically to act as a syncytium. Cardiac muscle cells contract autonomously and involuntarily. Smooth muscle is involuntary. Each cell is a spindle-shaped fiber and contains a single nucleus. No striations are evident because the actin and myosin filaments do not align in the cytoplasm. Choices: - cartilage tissue - organ - bone - muscle A:
**Answer**
muscle

Q: Some compounds containing hydrogen are members of an important class of substances known as what? Read this paragraph and choose the correct option from the provided answers: Binary Acids Some compounds containing hydrogen are members of an important class of substances known as acids. The chemistry of these compounds is explored in more detail in later chapters of this text, but for now, it will suffice to note that many acids release hydrogen ions, H+, when dissolved in water. To denote this distinct chemical property, a mixture of water with an acid is given a name derived from the compound's name. If the compound is a binary acid (comprised of hydrogen and one other nonmetallic element): 1. The word "hydrogen" is changed to the prefix hydro2. The other nonmetallic element name is modified by adding the suffix -ic 3. The word "acid" is added as a second word. Choices: - proteins - ions - bases - acids A:
acids