Bio 1 Midterm Exam Review

The structure labeled A is the cell wall. The cell wall is a rigid outer layer found in plant cells, fungi, and some bacteria. It provides support and protection to the cell, helping to maintain its shape and prevent it from bursting under pressure. The cell wall is made up of cellulose and other polysaccharides, and it acts as a barrier, regulating the movement of substances in and out of the cell.

The structure labeled A is the nucleus. The nucleus is a membrane-bound organelle found in eukaryotic cells. It contains the cell's genetic material, including DNA, and is responsible for controlling cellular activities such as gene expression and cell division. The nucleus is easily identifiable due to its distinct shape and location within the cell.

Structure D is labeled as mitochondrion. The mitochondrion is an organelle found in most eukaryotic cells and is responsible for generating energy in the form of ATP through cellular respiration. It has a double membrane structure and contains its own DNA. The presence of a double membrane and the function of energy production are characteristic features of mitochondria, making it the correct answer in this case.

The nucleus is the storehouse for most of a cell's genetic information. It contains the cell's DNA, which carries the instructions for the cell's functions and characteristics. The DNA is organized into structures called chromosomes, which are located inside the nucleus. The nucleus also controls the cell's activities by regulating gene expression and directing the synthesis of proteins. Therefore, the nucleus plays a crucial role in storing and managing the cell's genetic information.

Centrioles are small cylindrical structures found in animal cells that play a crucial role in cell division. They are responsible for organizing the microtubules that form the spindle fibers during mitosis, which help in the separation of chromosomes. Centrioles are typically located near the nucleus and are involved in the formation of cilia and flagella as well. Therefore, they are correctly labeled as F in the given structure.

The major principle upon which cell theory is based is that all organisms are made of cells. This principle states that cells are the basic structural and functional units of all living things. It emphasizes that all living organisms, from simple bacteria to complex multicellular organisms, are composed of cells. This principle was established by scientists Schleiden and Schwann in the 19th century and is a fundamental concept in biology.

Cytoplasm is the correct answer because it is the jelly-like substance that is contained inside the cell membrane. It is a semi-fluid material that fills the space between the cell membrane and the nucleus, and it contains various organelles and dissolved substances. The cytoplasm plays a crucial role in supporting the organelles and facilitating the movement of molecules within the cell.

Selective permeability refers to the property of a membrane or barrier to allow only certain molecules or ions to pass through while restricting the passage of others. In this case, the correct answer "some molecules pass" accurately describes selective permeability as it implies that only certain molecules are able to pass through the barrier, while others are not able to do so.

Structure B is labeled as chloroplast because chloroplasts are the organelles found in plant cells that are responsible for photosynthesis. They contain chlorophyll, a pigment that captures sunlight and converts it into energy for the cell. This organelle is not found in animal cells, making it a distinctive feature of plant cells.

Structure B is labeled as smooth E.R. Smooth endoplasmic reticulum (ER) is a network of membrane-bound tubules and sacs involved in various cellular functions. It lacks ribosomes on its surface, which gives it a smooth appearance. Smooth ER is responsible for lipid metabolism, detoxification of drugs and toxins, and calcium ion storage. It also plays a role in the production of hormones and lipids.

The correct answer is "Viruses are the smallest type of cell." This statement is not part of the Cell Theory because viruses are not considered cells. While they are microscopic and can replicate, viruses are not made up of cells and do not exhibit all the characteristics of living organisms. They are considered to be acellular entities that require a host cell to reproduce. Therefore, they are not included in the Cell Theory, which states that all living things are made of cells.

pH is the measure of hydrogen ions (H+) in a solution. It indicates the acidity or alkalinity of a solution on a scale of 0 to 14, with 0 being highly acidic, 7 being neutral, and 14 being highly alkaline. The pH scale is logarithmic, meaning that each whole number change in pH represents a tenfold difference in acidity or alkalinity. A lower pH value indicates a higher concentration of hydrogen ions, while a higher pH value indicates a lower concentration of hydrogen ions. Therefore, pH is the correct measure of hydrogen ions in a solution.

Rough ER is described as "studded with ribosomes" because it contains ribosomes on its surface. These ribosomes are responsible for protein synthesis, making rough ER involved in the production and processing of proteins. The rough appearance of the ER is due to the presence of ribosomes, which gives it a "studded" appearance.

Osmosis is the correct answer because it refers to the process of water molecules moving from an area of lower solute concentration to an area of higher solute concentration through a semipermeable membrane. This movement of water helps to equalize the concentration of solutes on both sides of the membrane, resulting in the establishment of equilibrium. The other options, such as equilibrium, transport, and isotonic, do not specifically describe the diffusion of water across a semipermeable membrane.

The correct answer is cell wall. Animal cells do not have a cell wall, unlike plant cells. The cell wall is a rigid outer layer that provides support and protection to plant cells. Animal cells, on the other hand, have a flexible cell membrane that allows for movement and interaction with the environment. The presence of mitochondria, Golgi apparatus, and vacuoles are all characteristic features of animal cells.

The cell pictured here is a prokaryote. Prokaryotes are single-celled organisms that lack a nucleus and other membrane-bound organelles. They are typically smaller and simpler in structure compared to eukaryotic cells. This can be inferred from the image, as prokaryotes usually have a simpler internal structure and lack a distinct nucleus, which is characteristic of eukaryotes.

DNA and RNA are two types of nucleic acids. Nucleic acids are macromolecules that are responsible for storing and transmitting genetic information in living organisms. DNA (deoxyribonucleic acid) is found in the nucleus of cells and carries the genetic instructions for the development and functioning of all living organisms. RNA (ribonucleic acid) is involved in the process of protein synthesis and helps in translating the genetic information stored in DNA into functional proteins. Therefore, the correct answer is nucleic acids.

In mitosis, sister chromatids separate during anaphase. During this phase, the microtubules attached to the centromeres shorten, pulling the sister chromatids apart and towards opposite ends of the cell. This ensures that each daughter cell receives a complete set of chromosomes. In contrast, metaphase is the phase where the sister chromatids align at the center of the cell, prophase is the phase where the chromosomes condense and the nuclear envelope breaks down, and telophase is the phase where the nuclear envelope reforms and the chromosomes decondense.

The cytoskeleton is a network of proteins that provides structural support and shape to a cell. It is responsible for maintaining cell shape, facilitating cell movement, and organizing cellular components. The cytoskeleton is composed of three main types of protein filaments: microtubules, intermediate filaments, and microfilaments. These filaments work together to give the cell its shape and allow for various cellular processes such as cell division and intracellular transport.

Ribosomes can be found on the surface of the endoplasmic reticulum. This is because the endoplasmic reticulum is involved in protein synthesis, and ribosomes are the cellular structures responsible for protein synthesis. The endoplasmic reticulum provides a surface for ribosomes to attach and carry out protein synthesis, allowing for efficient production and transport of proteins within the cell.

The structure labeled C is the vacuole. Vacuoles are membrane-bound organelles found in plant and fungal cells. They are responsible for storing various substances such as water, ions, and nutrients. Vacuoles also play a role in maintaining the turgor pressure of the cell and can contribute to cell growth and development.

Scientists use observations and data to form and test hypotheses. Hypotheses are educated guesses or proposed explanations for a phenomenon based on existing knowledge and observations. Scientists formulate hypotheses to guide their research and experiments, and then collect data to either support or refute these hypotheses. This process helps scientists advance their understanding of the natural world and develop new theories or conclusions based on the evidence gathered.

Hydrogen bonds give water many properties that are important to living things. Hydrogen bonds are formed between the positively charged hydrogen atoms of one water molecule and the negatively charged oxygen atoms of neighboring water molecules. These bonds give water a high boiling point, allowing it to exist as a liquid at room temperature. They also give water a high specific heat, meaning it can absorb and release large amounts of heat without significantly changing in temperature. Additionally, hydrogen bonds contribute to water's cohesion and surface tension, which are important for transporting nutrients and waste in living organisms.

Proteins are the fourth main type of carbon-based molecules in organisms. They are large, complex molecules made up of amino acids and are involved in various functions in the body, including structural support, enzymatic reactions, and transportation of molecules. Proteins are essential for the growth, repair, and maintenance of cells and tissues.

Atoms in molecules share pairs of electrons when they make covalent bonds. In a covalent bond, atoms share electrons in order to achieve a stable electron configuration. This sharing of electrons allows both atoms to fill their outermost energy levels and become more stable. This type of bond is commonly found in molecules and compounds composed of nonmetals. Ionic bonds involve the transfer of electrons, hydrogen bonds are a type of intermolecular bond, and polymers are large molecules made up of repeating subunits.

The nucleus is the storehouse for a cell's genetic information. It contains the cell's DNA, which carries the instructions for the cell's functions and characteristics. The DNA is organized into chromosomes and is protected within the nucleus. The nucleus also plays a role in regulating gene expression and controlling the cell's activities. Mitochondria and chloroplasts are involved in energy production and centrioles play a role in cell division, but they do not store genetic information like the nucleus does.

The cytoskeleton is a network of proteins that provides structural support to the cell and helps maintain its shape. It also plays a crucial role in cell movement, cell division, and the transport of materials within the cell. Vesicles are small membrane-bound sacs involved in transport, while vacuoles are storage organelles. The cytoplasm is the gel-like substance that fills the cell. Therefore, the correct answer is cytoskeleton.

The Golgi apparatus is responsible for processing and delivering proteins within the cell. It receives proteins from the endoplasmic reticulum, modifies them by adding sugars and other molecules, and packages them into vesicles for transport to their final destinations. This process ensures that proteins are properly folded, modified, and sorted before being sent to different parts of the cell or secreted outside. Therefore, the main function of the Golgi apparatus is to process and deliver proteins.

When graphing experimental results, the dependent variables should be placed onto the y-axis. The dependent variables are the ones that are being measured or observed in the experiment and are expected to change as a result of manipulating the independent variables. Placing the dependent variables on the y-axis allows for a clear representation of the relationship between the independent and dependent variables, as the y-axis represents the variable that is being affected by the independent variable.

Fats, oils, and cholesterol are all types of lipids. Lipids are a class of organic compounds that are insoluble in water but soluble in organic solvents. They are an essential component of living cells and play important roles in energy storage, insulation, and cushioning of organs. Hormones, cell membranes, and fatty acids are all related to lipids, but they are not inclusive of all types of lipids.

The student's observation of various organisms living in and around the rotted log suggests that they are all part of a community. A community refers to a group of different species that interact and coexist in a particular area. In this case, the fungi, termites, pill bugs, ants, slugs, and earthworms are all living together and interacting within the same habitat, forming a community.

If the Daphnia are killed with pesticides, the primary consumer in the pond will be eliminated. As a result, the primary producer, Spirogyra, will not be consumed and its population will likely increase. With the increase in Spirogyra population, the primary consumer, Daphnia, will not be able to eat something else and its population will decline. Consequently, the secondary consumer, bluegill, will have less food available and its population will probably decrease. As the bluegill population decreases, the tertiary consumer, smallmouth bass, will also have less food and may not be able to survive, leading to the death of the smallmouth bass population.

The carrying capacity of a population in an ecosystem refers to the average maximum number of individuals that the ecosystem can support. It represents the point at which the available resources in the ecosystem can no longer sustain any additional individuals, resulting in a balance between births and deaths. It is not related to the rate at which individuals die off, the amount of animals in the entire biome, or how an ecosystem can carry a population to another ecosystem.

The entire structure shown in the diagram is responsible for regulating what goes in and out of a cell. This suggests that it is involved in maintaining the cell's internal environment and controlling the movement of substances across the cell membrane. It may include various components such as transport proteins, ion channels, and receptors that help in the selective transport of molecules and ions.

Flagella are not found in plant cells. Flagella are whip-like structures that are responsible for cell movement in many organisms, including some bacteria and single-celled eukaryotes. However, plant cells do not have flagella. Instead, plant cells have rigid cell walls and use other mechanisms, such as the growth and movement of specialized cells, to achieve movement and transport. Therefore, flagella are not present in plant cells.

The structure labeled C is the rough endoplasmic reticulum (rough E.R.). This can be determined because the rough E.R. is responsible for protein synthesis and has ribosomes attached to its surface, which are visible in the given diagram. The other options, such as the nucleus, mitochondrion, and smooth E.R., do not have these characteristics.

The given correct answer is "animal cell." This is because the image or description provided in the question most likely depicts a cell that lacks a distinct nucleus and membrane-bound organelles, which are characteristic features of eukaryotic cells. Animal cells are a type of eukaryotic cell, while prokaryotes, such as bacteria, do not possess a nucleus or membrane-bound organelles. Additionally, the options of "bacterial" and "plant cell" can be eliminated based on the information provided.

An element is a pure substance made of only one kind of atom. It cannot be broken down into simpler substances and retains its unique properties. Examples of elements include hydrogen, oxygen, and gold. Compounds, on the other hand, are made up of two or more different elements chemically combined. Atoms are the basic building blocks of matter, while ions are atoms or molecules that have gained or lost electrons, resulting in a net positive or negative charge.

A solute is a substance that dissolves in a solvent.

A concentration gradient refers to the difference in the concentration of dissolved particles between two locations. It represents how the concentration changes from one point to another, with higher concentration areas having a steeper gradient. This term is commonly used in various scientific fields, such as biology and chemistry, to describe the movement of substances or the distribution of solutes in a solution.

The structure labeled C in Fig. 3.3 is the Endoplasmic Reticulum.

The Golgi apparatus is responsible for processing and delivering proteins within the cell. Proteins synthesized in the endoplasmic reticulum are modified and packaged in the Golgi apparatus before being transported to their final destinations within or outside the cell. This organelle plays a crucial role in protein sorting, glycosylation, and the formation of vesicles for protein transport. Therefore, the main function of the Golgi apparatus is to process and deliver proteins.

A covalent bond forms when atoms share a pair of electrons. This type of bond occurs between nonmetal atoms, where the electrons are shared equally between the atoms. In a covalent bond, the atoms are held together by the attraction between the shared electrons and the positively charged nuclei of the atoms involved. This sharing of electrons allows the atoms to achieve a more stable electron configuration, resulting in a strong bond between the atoms.

An atom is the smallest unit of matter that cannot be broken down by chemical means. It consists of a nucleus, which contains protons and neutrons, and electrons that orbit around the nucleus. Atoms of different elements have different numbers of protons, giving them unique properties. Chemical reactions involve the rearrangement of atoms to form compounds, but the atoms themselves remain unchanged. Therefore, an atom is the correct answer as it is the fundamental building block of all matter.

An atom is the smallest basic unit of matter. It is composed of protons, neutrons, and electrons. Atoms combine to form molecules, which are the building blocks of all substances. Cells are the basic units of life, but they are not the smallest units of matter. Compounds are formed when atoms of different elements combine chemically. Therefore, the correct answer is atom.

The structure labeled E is the Golgi body. The Golgi body is responsible for modifying, sorting, and packaging proteins and lipids into vesicles for transport within the cell or for secretion outside of the cell. It consists of a series of flattened membrane sacs called cisternae. The Golgi body plays a crucial role in the intracellular transport and processing of proteins and is involved in the synthesis of cell wall components, lysosomes, and secretory vesicles.

Cohesion refers to the attraction between substances of the same kind. It is the force that holds molecules of the same substance together. This can be observed in the way water molecules stick to each other, forming droplets or creating surface tension. Cohesion is responsible for many properties of liquids, such as their ability to flow and form spherical shapes. It is an important concept in chemistry and physics.

The correct answer is Active transport. Active transport is a type of cellular transport that requires energy to move molecules or ions across a cell membrane against their concentration gradient. In the diagram, the transport process is shown to be moving molecules from an area of lower concentration to an area of higher concentration, which is characteristic of active transport.

Lysosomes contain enzymes that break down old cell parts. Lysosomes are membrane-bound organelles found in animal cells. They are responsible for breaking down waste materials, cellular debris, and old or damaged organelles through a process called autophagy. This process helps maintain the overall health and functioning of the cell by recycling and eliminating unnecessary or damaged components.

Chloroplasts are organelles that are found only in plant cells. They are responsible for photosynthesis, the process by which plants convert sunlight into energy. Chloroplasts contain chlorophyll, a pigment that gives plants their green color and allows them to absorb sunlight. This organelle is not found in animal cells, making it unique to plant cells. Centrosomes, ribosomes, and vacuoles, on the other hand, can be found in both plant and animal cells.