Biology B - Unit 2 Practice Test

The mitochondria are labelled with the number 1.

Mitochondria is the correct answer because it is known as the "powerhouse" of the cell. It is responsible for producing energy in the form of ATP through a process called cellular respiration. Mitochondria contain their own DNA and are able to generate ATP by breaking down glucose and other molecules. This energy is then used by the cell for various metabolic activities and processes.

The Golgi complex is responsible for packaging and transporting proteins and lipids within the cell. It receives molecules from the endoplasmic reticulum and modifies them by adding sugars and other molecules. It then packages these modified molecules into vesicles and sends them to their appropriate destinations within the cell or outside of the cell. Therefore, the Golgi complex plays a crucial role in the packaging and transport of molecules, making it the correct answer.

The correct answer is Eukaryota because eukaryotes are organisms that contain nuclei. This domain includes animals, plants, fungi, and protists. Eukaryotic cells are characterized by having a membrane-bound nucleus that houses their genetic material, as well as other membrane-bound organelles. In contrast, archaea and bacteria are prokaryotes, which do not have a true nucleus or membrane-bound organelles.

A solution with a lower solute concentration than that of a cell is called hypotonic. In a hypotonic solution, there is a higher concentration of water molecules compared to solute molecules. When a cell is placed in a hypotonic solution, water will move into the cell through osmosis, causing the cell to swell or potentially burst. This is because the concentration of solutes inside the cell is higher than the concentration of solutes in the hypotonic solution.

Osmosis is the process of water diffusion across a selectively permeable membrane. This means that water molecules move from an area of lower solute concentration to an area of higher solute concentration, in order to equalize the concentration on both sides of the membrane. This process is important for maintaining the balance of water and solutes in living organisms, as well as for various biological processes. Hydration refers to the process of adding water to a substance, distillation is a method of separating liquids based on their boiling points, and distribution refers to the act of spreading or delivering something.

Based on the above image, this cell would belong to the kingdom Plantae. The image shows a cell with a cell wall, which is a characteristic feature of plant cells. Animal cells do not have a cell wall, while cells in the Monera kingdom are prokaryotic and lack a true nucleus. Fungi cells have a cell wall, but they also have other distinct features such as chitin in their cell walls, which is not visible in the image.

Enzymes are proteins that act as catalysts in biological reactions. They speed up the rate of chemical reactions in the body without being consumed or altered in the process. Enzymes play a crucial role in various metabolic processes, including digestion, energy production, and DNA replication. They are highly specific in their actions and can be regulated to maintain optimal conditions for biochemical reactions. Enzymes are essential for the proper functioning of cells and are involved in almost every biological process in the body.

The correct answer is Plantae because the description provided matches the characteristics of plants. Plants are multicellular, photosynthetic autotrophs that have cell walls containing cellulose. Animalia refers to animals, Fungi refers to fungi, and Protista refers to a group of diverse eukaryotic organisms, none of which match the given description.

Plants and fungi have cell walls in common, which animal cells lack. Cell walls provide structural support and protection to the cells, helping them maintain their shape and resist external pressures. They also regulate the movement of substances in and out of the cell. While animal cells have a flexible cell membrane, plants and fungi have an additional rigid cell wall made of cellulose or chitin, respectively. This difference in cell structure is one of the key distinctions between plant/fungal cells and animal cells.

Bacteria appeared on Earth first. Bacteria are single-celled microorganisms that have been present on Earth for billions of years. They are considered to be one of the earliest forms of life and played a crucial role in shaping the Earth's ecosystem. Bacteria were able to adapt and survive in various environments, paving the way for the evolution of other life forms such as plants, animals, and fungi.

Ribosomes are small, spherical organelles found in the cytoplasm of cells. They are responsible for protein synthesis, translating the genetic information from the DNA into functional proteins. Ribosomes can be found either floating freely in the cytoplasm or attached to the endoplasmic reticulum. They are composed of RNA and proteins, and their main function is to assemble amino acids into polypeptide chains, which then fold into functional proteins. Ribosomes play a crucial role in the growth, development, and functioning of cells, making them an essential organelle in all living organisms.

The correct answer is "Fine Focus" because a knob that makes small adjustments to the focus of a microscope is used to bring the specimen into sharp focus. This knob allows for precise focusing and is particularly useful when working with high magnification objectives, where even the slightest movement can cause the image to become blurry. The fine focus knob is typically smaller and more sensitive than the coarse focus knob, which is used for larger adjustments to the focus.

The magnification of a microscope is calculated by multiplying the magnification of the ocular lens with the magnification of the objective lens. In this case, the ocular lens has a magnification of 10X and the objective lens has a magnification of 4X. Therefore, the magnification of the microscope is 10X multiplied by 4X, which equals 40X.

The rough appearance of the Endoplasmic Reticulum is caused by ribosomes. Ribosomes are small organelles that are responsible for protein synthesis. They are attached to the surface of the Endoplasmic Reticulum, giving it a rough texture. This rough E.R., also known as the rough endoplasmic reticulum, plays a crucial role in the production, folding, and transport of proteins within the cell.

The cell membrane is a phospholipid layer that covers a cell's surface and acts as a barrier between the inside of a cell and the cell's environment. It regulates the movement of substances in and out of the cell, allowing for the maintenance of homeostasis. It is composed of a double layer of phospholipids with embedded proteins that help in various cellular functions such as transport, signaling, and cell recognition. The cell membrane is essential for the survival and proper functioning of a cell.

Fungi play a large role in the digestion and repurposing of dead and decaying material. They are decomposers, breaking down organic matter and releasing nutrients back into the environment. Fungi secrete enzymes that break down complex molecules, allowing them to absorb the nutrients. This process is crucial for nutrient cycling and ecosystem functioning.

The level of enlargement of an object is determined by the magnification. It is equal to the power of the objective lens multiplied by the power of the ocular lens. Magnification refers to the increase in apparent size of an object when viewed through a microscope or other optical instrument.

A unicellular organism that lacks a nucleus and membrane-bound organelles is classified as a prokaryote. Prokaryotes are typically single-celled organisms, such as bacteria, that do not have a defined nucleus or other specialized compartments within their cells. They have a simple structure and their genetic material is not enclosed within a membrane-bound nucleus. This is in contrast to eukaryotes, which are organisms with complex cells that contain a nucleus and membrane-bound organelles.

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Eukaryotes are larger and have membrane-bound organelles. This means that eukaryotic cells are generally bigger in size compared to prokaryotic cells. Eukaryotes have specialized compartments within their cells called organelles, such as the nucleus, mitochondria, and endoplasmic reticulum, which are enclosed by membranes. Prokaryotes, on the other hand, lack these membrane-bound organelles and their genetic material is not enclosed within a nucleus.

Archaea are a domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan. They are known to grow in extreme environments. This is why they are the correct answer to the question. Animalia, Eukaryota, and Lysosome are not relevant to the given characteristics.

The correct answer is Vacuole. A vacuole is a cell organelle that stores various materials such as water, salts, proteins, and carbohydrates. It plays a crucial role in maintaining the cell's internal environment, storing nutrients, and regulating cellular processes. Vacuoles are particularly prominent in plant cells, where they can occupy a significant portion of the cell's volume. They also aid in maintaining turgor pressure, which is important for plant cell structure and support.

Mitochondria is the correct answer because it is an organelle that is responsible for cellular respiration. It uses oxygen to break down organic molecules and produce ATP, which is the main energy source for the cell. This process occurs in the mitochondria's inner membrane, where the electron transport chain and ATP synthesis take place. Therefore, mitochondria are crucial for energy production in cells.

Bacteria are prokaryotic organisms because they lack a nucleus and membrane-bound organelles. Prokaryotes are characterized by their simple cell structure, with genetic material floating freely in the cytoplasm. Plants, animals, and fungi, on the other hand, are eukaryotic organisms. They have a complex cell structure with a nucleus and membrane-bound organelles.

An organ system is a group of organs that work together to perform vital body functions. This system consists of multiple organs that have specific roles and functions, and they collaborate to maintain homeostasis and ensure the overall well-being of the body. Each organ within the system has a unique purpose, but they all work together in a coordinated manner to carry out necessary functions such as digestion, respiration, circulation, and excretion. The organ system concept allows for specialization and efficiency in performing complex tasks, ensuring the survival and proper functioning of the organism.

The cellular membrane is made up of lipids, which have a polar head and a non-polar tail. This arrangement allows the lipids to form a bilayer structure, with the polar heads facing towards the watery environment both inside and outside the cell, while the non-polar tails are oriented towards the interior of the membrane. This arrangement creates a barrier that separates the cell's internal environment from the external environment, while still allowing certain molecules to pass through the membrane.

An acid is a substance that has a pH value below 7 and a high concentration of H3O+. Acids are known for their ability to donate protons (H+) in chemical reactions. The high concentration of H3O+ ions in an acid is what gives it its acidic properties, such as sour taste and the ability to react with bases to form salts.

The given description states that the kingdom is made up of complex, multicellular organisms that lack cell walls, can usually move around, and quickly respond to their environment. Among the given options, Animalia is the only kingdom that fits this description. Animalia consists of organisms such as mammals, birds, reptiles, and insects, which are all multicellular, lack cell walls, and have the ability to move and respond to their surroundings. Therefore, Animalia is the correct answer.

The area of the microscope where a slide is placed is called the stage. This is where the specimen or slide is placed and secured for observation under the microscope. The stage typically has clips or mounts to hold the slide in place, ensuring it remains steady during examination. The stage is an essential component of the microscope, as it allows for precise positioning and focus on the specimen being observed.

Diffusion is the correct answer because it refers to the movement of molecules from an area of higher concentration to an area of lower concentration. This process occurs due to the random motion of particles and does not require any external energy. Osmosis, on the other hand, specifically refers to the movement of water molecules across a selectively permeable membrane, while hypertonic and isotonic refer to the concentration of solutes in a solution compared to another solution.

The three domains of life are Eukaryota, Bacteria, and Archaea. These domains represent the three major groups into which all living organisms are classified. Eukaryota includes organisms with complex cells that have a nucleus, such as animals, plants, fungi, and protists. Bacteria are single-celled organisms that lack a nucleus and are found in various environments. Archaea are also single-celled organisms that lack a nucleus, but they have distinct genetic and biochemical characteristics that set them apart from bacteria. These three domains provide a framework for understanding the diversity and relationships among all living organisms.

A cell might burst if it is placed under hypotonic conditions. In a hypotonic solution, the concentration of solutes outside the cell is lower than inside the cell. As a result, water will move into the cell through osmosis, causing it to swell and potentially burst.

The large knob used only under low power objective on the microscope is the coarse focus. This knob is responsible for making rough adjustments to the focus of the specimen. It moves the stage up and down, allowing the user to quickly bring the specimen into approximate focus. Once the specimen is roughly focused using the coarse focus, the fine focus knob can be used to make more precise adjustments and bring the specimen into clear focus. The diaphragm is responsible for controlling the amount of light passing through the specimen, and the stage is the platform on which the specimen is placed.

Number 9 is important in the production of proteins because proteins are made up of amino acids, and the DNA sequence determines the order of amino acids in a protein. Number 9 refers to the nitrogenous base adenine, which is one of the four bases found in DNA. Adenine pairs with thymine in DNA, and the sequence of these base pairs provides the instructions for building proteins. Therefore, number 9 (adenine) is crucial for the production of proteins.

The image shows a cell in a hypertonic solution. In a hypertonic solution, the solute concentration outside the cell is higher than inside the cell. This causes water to move out of the cell, leading to cell shrinkage or crenation.

A vesicle is a small, membrane-bound sac that transports substances in cells. It is responsible for the movement of molecules, such as proteins and lipids, within the cell. Vesicles are involved in various cellular processes, including secretion, endocytosis, and exocytosis. They play a crucial role in maintaining the integrity and functionality of the cell by facilitating the transportation of molecules to their respective destinations.

The objective lens is the correct answer because it is the lens that is positioned immediately above the object being magnified on a microscope. This lens is responsible for collecting light from the object and forming a magnified image that can be viewed through the ocular lens. The other options, such as the ocular lens, obtuse lens, and osmosis lens, are not relevant to the specific task of magnifying objects on a microscope.

Archaea is the correct answer because archaea are known to thrive in extreme environments, including those with low oxygen levels. They are single-celled organisms that belong to a separate domain from bacteria and eukaryotes. While some bacteria can also survive in low oxygen conditions, the fact that this organism is pictured suggests that it is a representative of the archaea domain.

Algae and Protozoa both belong to the kingdom Protista. Protista is a diverse group of eukaryotic organisms that do not fit into the other kingdoms such as Plantae or Animalia. Algae are photosynthetic organisms that can range from single-celled to multicellular forms, while Protozoa are single-celled heterotrophic organisms. Both Algae and Protozoa share similar characteristics and are classified under Protista due to their unique features and evolutionary relationships.

A solution with a higher solute concentration than that of a cell is called hypertonic. In a hypertonic solution, there is a greater concentration of solutes outside the cell compared to inside the cell. This creates an osmotic gradient, causing water to move out of the cell in an attempt to equalize the solute concentration. As a result, the cell may shrink or undergo dehydration.

The correct answer is Bacteria. Bacteria are infectious, prokaryotic organisms. They are single-celled microorganisms that can cause various diseases in humans, animals, and plants. They have a simpler cell structure compared to eukaryotic organisms and can reproduce rapidly. Bacteria play important roles in various ecological processes and can have both beneficial and harmful effects on living organisms.

Ribosomes are the cytoplasmic organelles responsible for protein synthesis. They are composed of RNA and protein molecules and can be found freely floating in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes read the genetic information encoded in messenger RNA (mRNA) and use it as a template to assemble amino acids into proteins. Therefore, ribosomes are the correct answer because they play a crucial role in protein synthesis within the cell.

The correct order for placing the items on a slide in a wet mount is as follows: first, the specimen is placed on the slide. Then, water is added to the slide to provide a medium for the specimen. Finally, the coverslip is placed on top to secure the specimen and prevent it from moving.

Fungi are a kingdom of complex organisms that obtain food by breaking down other substances in their surroundings and absorbing the nutrients. They do not possess chlorophyll, so they cannot photosynthesize like plants. Instead, fungi secrete enzymes that break down organic matter, such as dead plants or animals, and absorb the nutrients from it. This process is known as decomposition. Fungi play a crucial role in ecosystems by recycling nutrients and breaking down organic matter, making them an essential part of the food chain.

The diaphragm of a microscope is responsible for controlling the amount of light that passes through the slide. By adjusting the diaphragm, the user can increase or decrease the amount of light transmitted, which can help improve the clarity and visibility of the specimen being observed. The diaphragm acts as a sort of aperture, allowing the user to fine-tune the lighting conditions for optimal viewing.

The Golgi apparatus is a system of membranes found in a cell's cytoplasm that plays a crucial role in the production, processing, and transport of proteins and lipids. It receives proteins and lipids from the endoplasmic reticulum and modifies them by adding sugars and other molecules. It then packages these modified proteins and lipids into vesicles and transports them to their final destinations within the cell or to the cell membrane for secretion. Therefore, the Golgi apparatus is responsible for the sorting, processing, and packaging of molecules, making it the correct answer in this case.

The coarse focus knob can be used under the circumstance of low power. This is because the coarse focus knob is designed to make large adjustments to the focus of the microscope, which is more necessary when using lower magnification levels. At higher magnification levels, finer adjustments are required, and the fine focus knob is used instead. Therefore, the coarse focus knob is most effective and commonly used when working with low power settings.

The endoplasmic reticulum is a system of membranes that modifies and packages proteins for export by the cell. It is responsible for synthesizing proteins and lipids, as well as detoxifying drugs and alcohol. The endoplasmic reticulum plays a crucial role in protein synthesis and transport within the cell, making it the correct answer for this question.