Bio 101 Lab Exam Pt 2

The correct answer is true because translucent refers to a material or substance that allows light to pass through but does not allow detailed images to be seen. It is semitransparent, meaning that it allows some light to pass through, but not enough for clear or detailed images to be visible.

Prokaryotes are mainly bacteria because prokaryotes are single-celled organisms that lack a nucleus and membrane-bound organelles. Bacteria are a type of prokaryote, characterized by their simple cellular structure and ability to adapt to various environments. While plants and animals are eukaryotes with more complex cellular structures, prokaryotes, such as bacteria, have distinct characteristics that differentiate them from other organisms. Therefore, the correct answer is bacteria.

When a blood cell is placed in a hypertonic solution, the solution has a higher concentration of solutes compared to the cell. As a result, water from inside the cell will move outwards through osmosis, causing the cell to lose water and shrink in size. Therefore, the correct answer is "shrink".

When an enzyme is warmed, it increases the kinetic energy of the molecules, including the enzyme and the substrate. This increased energy allows for more frequent collisions between the enzyme and substrate, increasing the rate of reaction. Therefore, the enzyme will work on the substrate faster when warmed.

To find the total magnification of a specimen, you need to multiply the magnification of the objective lens with the magnification of the ocular lens. The objective lens is responsible for the initial magnification of the specimen, while the ocular lens further magnifies the image formed by the objective lens. The stage is where the specimen is placed, the condenser helps focus the light onto the specimen, and the light source provides illumination, but they do not directly contribute to the total magnification. Therefore, the correct answer is the ocular lens.

The statement is false. Benedicts solution is not used to test for starch. Instead, it is used to test for the presence of the aldehyde functional group, -CHO. It is a deep-blue alkaline solution that changes color to orange or red when an aldehyde is present.

The colors green, red, yellow, and orange have specific meanings when testing for sugar. Green indicates a relatively low amount of sugar, while brown or red precipitate suggests a higher concentration of sugar. Orange and red indicate the highest proportion of these sugars. A yellowish brown color, on the other hand, indicates a negative result for sugar. Therefore, all of these colors have different interpretations when testing for sugar.

Orange juice contains all of the mentioned components: pure fruit juice, water, sugar, and additives. Additionally, it is a good source of vitamin C. It does not contain vitamin D3, as this vitamin is not naturally present in orange juice.

The measurement of the high power field of view is 0.450 mm. If a specimen takes up 1/10 of the field, it means that the specimen occupies 1/10 of 0.450 mm. To find the size of the specimen, we can divide 0.450 mm by 10, which gives us 0.045 mm. Therefore, the specimen is 0.045 mm in size.

Albumin is a simple form of protein that is soluble in water and coagulable by heat. It is found in various substances such as egg white, milk, and blood serum. Therefore, the correct answer is "all of the above" as albumin meets all the mentioned characteristics.

If you denature the enzyme, it means that you have altered its structure and destroyed its active site. The active site is the region of the enzyme where the substrate binds and the chemical reaction takes place. Without a functional active site, the enzyme is unable to catalyze the reaction, rendering it completely ineffective. Therefore, denaturing the enzyme will cause it to not work at all.

The wall of a plant cell is composed of a rigid structure called the cell wall, which provides support and protection to the cell. In a hypotonic solution, where the external environment has a lower solute concentration compared to the cell's cytoplasm, water tends to move into the cell by osmosis. However, the cell wall prevents excessive water uptake and expansion of the cell, thereby preventing it from bursting or "popping".

Lugols is a solution made from iodine and potassium iodide. It is orange in color and is commonly used to test for the presence of starch.

The correct answer is 45 um because the question asks for the size of the specimen in micrometers (microns) and 45 um is the only option given in micrometers.

Cyanobacteria are autotrophs because they are capable of photosynthesis, using sunlight to convert carbon dioxide and water into glucose and oxygen. They possess pigments, such as chlorophyll, which enable them to capture light energy and carry out this process. This ability to produce their own food distinguishes them from heterotrophs, which rely on obtaining nutrients from external sources, and from plants, which are a specific group of autotrophs but not the only ones. Therefore, cyanobacteria are classified as autotrophs.

Eukaryotes are different from prokaryotes because they have both nuclei and organelles. Prokaryotes, such as bacteria, do not have a defined nucleus or membrane-bound organelles. On the other hand, eukaryotes, including plants, animals, fungi, and protists, have a distinct nucleus that houses their genetic material and various membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus. These organelles perform specific functions within the cell, contributing to the complexity and efficiency of eukaryotic organisms.

Biuret reagent is a chemical test used to detect the presence of proteins and polypeptides. It is a solution that contains potassium hydroxide (KOH) and copper sulfate. When mixed with a protein or polypeptide, a color change occurs, indicating the presence of these substances. Therefore, the correct answer is "all of these" because Biuret reagent consists of potassium hydroxide and is used as a chemical test for proteins and polypeptides.

Parfocal refers to the property of a microscope where the specimen remains in focus when switching between different objective lenses without needing significant adjustments to the focus. In this case, the fact that the specimen remains in focus under both the 10X and 40X lenses after rotating it into position indicates that the microscope is parfocal.

The lens that should be set to store the scope should be the scanning lens. This is because the scanning lens provides a wider field of view and is used for locating and observing objects at low magnification. Storing the scope with the scanning lens ensures that it is ready for general use and allows for easy scanning of the specimen. The low power and high power lenses are used for higher magnification and detailed observation, respectively, and are not suitable for storing the scope.

The rheostat of a microscope controls the intensity of the light. Setting it at 7 ensures that the light is at an appropriate brightness level for viewing the specimen. This setting allows for a clear and detailed image without causing any strain on the eyes.