Biology Chapter 4 & 5

A cell that contains a cell wall, chloroplasts, and a central vacuole is a plant cell. Plant cells have a cell wall, which provides structure and support to the cell. Chloroplasts are also present in plant cells, allowing them to carry out photosynthesis and produce energy. The central vacuole, found in plant cells, stores water, nutrients, and waste materials. Animal cells do not have a cell wall or chloroplasts, and their vacuoles are smaller and more numerous. Prokaryotic and bacterial cells are different types of single-celled organisms and do not have the specific characteristics mentioned in the question.

Chloroplasts are a unique organelle found in plant cells but not in animal 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 light energy. This energy is then used to convert carbon dioxide and water into glucose and oxygen. Animal cells do not have chloroplasts because they obtain energy through other means, such as consuming plants or other animals. Therefore, the correct answer is chloroplast.

The correct answer is "cells come from other cells." This is supported by the concept of cell division, where cells replicate and give rise to new cells. This process is observed in both plants and animals, indicating that cells are not only the building blocks of organisms but also have the ability to reproduce and give rise to new cells. This observation provides evidence for the cell theory, which states that all living organisms are composed of cells and that cells are the basic units of life.

Living things are made of cells because cells are the basic structural and functional units of life. All living organisms, from single-celled bacteria to complex multicellular organisms like humans, are composed of cells. Cells carry out various life processes such as metabolism, reproduction, and response to stimuli. In contrast, nonliving things do not possess cells and do not exhibit the characteristics of life. They may be made up of atoms or molecules, but they lack the organization and complexity seen in living organisms. Therefore, the presence of cells is a defining characteristic of living things.

Eukaryotic cells have membrane-bound organelles, which means that their organelles are enclosed by a membrane. This is a key difference between eukaryotic and prokaryotic cells. Prokaryotic cells, on the other hand, do not have membrane-bound organelles. Instead, their genetic material floats freely in the cytoplasm.

Cells that have a high energy requirement generally have many mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for producing the majority of the cell's energy in the form of ATP through cellular respiration. Cells that require a lot of energy, such as muscle cells or nerve cells, need a larger number of mitochondria to meet their energy demands. Therefore, the presence of many mitochondria in a cell is indicative of its high energy requirement.

The major event in the history of cell biology is the discovery of cell parts, which includes the identification and understanding of various components within a cell. This breakthrough has paved the way for further advancements in the field. Additionally, cloning animals and growing bone tissue for transplant are significant achievements that have also contributed to the progress of cell biology. Therefore, all of the given options are major events in the history of cell biology.

Lysosomes are responsible for breaking down viruses, bacteria, and old organelles that a cell ingests. They contain enzymes that can break down various molecules, including proteins, nucleic acids, and lipids. This process, known as autophagy, helps to recycle and eliminate cellular waste, ensuring the cell's proper functioning. Therefore, lysosomes are the correct answer for this question.

Pinocytosis is a type of endocytosis where the cell takes in fluids and dissolved solutes from its surroundings. This process involves the formation of small vesicles at the cell membrane that enclose the extracellular fluid and bring it into the cell. These vesicles then fuse with the cell's internal compartments, allowing the cell to internalize the fluids and their contents. Therefore, the correct answer is "fluids into a cell."

Substances produced in a cell and exported outside of the cell would pass through the endoplasmic reticulum and Golgi apparatus. The endoplasmic reticulum is responsible for the synthesis and modification of proteins and lipids, while the Golgi apparatus further modifies and packages these substances into vesicles for transport. These vesicles then fuse with the cell membrane, allowing the substances to be released outside of the cell. The mitochondria is responsible for energy production, the nucleus contains the cell's genetic material, and lysosomes and vacuoles are involved in intracellular digestion and storage, respectively.

The correct answer is nucleus and mitochondria. The nucleus is surrounded by a double membrane and contains DNA, which is responsible for storing genetic information. Mitochondria are also surrounded by a double membrane and contain their own DNA, known as mitochondrial DNA. They are responsible for producing energy in the form of ATP through cellular respiration. Both organelles play crucial roles in the cell's functions and are involved in genetic processes.

Oxygen can pass through cell membranes by diffusion because it is a small molecule and is nonpolar. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, and it occurs passively without the need for energy. Cell membranes are selectively permeable, meaning they allow certain molecules to pass through while restricting others. Since oxygen is small and nonpolar, it can easily diffuse through the lipid bilayer of the cell membrane.

Cells are limited in size by the rate at which substances needed by the cell can enter the cell through its surface. This is because cells rely on the diffusion of substances across their membrane to obtain nutrients and eliminate waste. If a cell grows too large, the surface area available for diffusion becomes insufficient to meet the cell's needs. Therefore, the rate at which substances can enter the cell through its surface determines its size limitation.

The correct answer is Na+ out of the cell and K+ into the cell. The sodium-potassium pump is an active transport protein that uses energy from ATP to move sodium ions out of the cell and potassium ions into the cell. This process helps to maintain the electrochemical gradient across the cell membrane and is essential for proper cell function.

Exocytosis is a transport process in which vesicles are formed from pouches in the cell membrane. These vesicles contain large molecules, such as proteins, and are released from the cell into the extracellular space. This mechanism allows cells to export substances that are too large to pass through the cell membrane directly.

The correct answer is the fusion of smaller vacuoles. The central vacuole in plant cells is formed by the fusion of multiple smaller vacuoles. As the smaller vacuoles merge together, they create a larger central vacuole that occupies most of the cell's interior. This central vacuole plays a crucial role in maintaining turgor pressure, storing water, nutrients, and waste products, and regulating cell growth and expansion.

Robert Hooke is the correct answer because he was the scientist who first described cells as "many little boxes" in his book Micrographia published in 1665. In this book, Hooke used a microscope to observe cork cells and coined the term "cell" to describe the small compartments he observed. His work was significant in establishing the concept of cells and laying the foundation for the development of cell theory.

The plasma membrane is composed mainly of a lipid bilayer. This means that it is made up of two layers of lipids, specifically phospholipids. The lipid bilayer provides a barrier that separates the inside of the cell from the outside environment. It is selectively permeable, allowing certain substances to pass through while preventing others from entering or leaving the cell. This property is essential for maintaining homeostasis and regulating the movement of molecules in and out of the cell.

The contractile vacuole of a paramecium should be active when the paramecium is in a hypotonic environment. In a hypotonic environment, the concentration of solutes outside the paramecium is lower than inside the cell. As a result, water moves into the cell through osmosis, causing the cell to swell and potentially burst. The contractile vacuole helps to regulate the water balance by pumping out excess water from the cell, preventing it from bursting. In isotonic and hypertonic environments, the concentration of solutes is balanced or higher outside the cell, respectively, so there is no need for the contractile vacuole to be active.

Thylakoids are located inside the inner membrane of a chloroplast. Thylakoids are membrane-bound compartments that contain chlorophyll and other pigments necessary for photosynthesis. They are stacked together in structures called grana, which are found inside the chloroplasts. The inner membrane of the chloroplast surrounds the stroma, a gel-like substance where the Calvin cycle of photosynthesis takes place. Therefore, the thylakoids being inside the inner membrane of a chloroplast is the correct answer.

Na+ ions enter cells by diffusing through Na+ ions channels. These channels provide a pathway for the Na+ ions to move across the cell membrane, allowing them to passively diffuse from an area of higher concentration to an area of lower concentration. This process does not require the assistance of carrier proteins or the binding of CL+ ions. The presence of specific Na+ ions channels facilitates the movement of Na+ ions into the cell.

When a human red blood cell is placed in a hypotonic environment, it means that the concentration of solutes outside the cell is lower than inside the cell. This causes water to move into the cell, leading to an increase in cell volume. Eventually, the cell membrane becomes stretched and ruptures, resulting in the bursting of the cell. This process is known as cytolysis. Therefore, the correct answer is "undergo cytolysis."

The characteristic of a nerve cell that relates directly to its function in receiving and transmitting nerve impulses is its long extensions. These long extensions, called axons and dendrites, allow nerve cells to receive information from other cells and transmit electrical signals throughout the body. The length of these extensions enables the nerve cell to communicate over long distances, ensuring efficient transmission of nerve impulses.

Facilitated diffusion carrier proteins and cell membrane pumps are specific for the kinds of substances they transport. This means that they are designed to bind to specific molecules and transport them across the cell membrane. This specificity allows them to selectively transport certain substances while excluding others. Unlike active transport, facilitated diffusion and cell membrane pumps do not require an input of energy to transport substances. Instead, they rely on the concentration gradient of the substances to facilitate their movement across the membrane.

Microscopes were used to study cells beginning in the 17th century. This is because the invention of the compound microscope in the 17th century allowed scientists to observe cells in greater detail. Prior to this, simple microscopes were used, but they had limited magnification and resolution. With the advancement of microscopy technology in the 17th century, scientists such as Robert Hooke were able to make significant discoveries about cells, leading to the development of the cell theory and the field of cell biology.

Facilitated diffusion is a type of passive transport that helps molecules move across the cell membrane. It is used specifically for molecules that are not soluble in lipids, as they cannot easily pass through the hydrophobic lipid bilayer of the membrane. Facilitated diffusion involves the use of carrier proteins or channel proteins to assist in the transport of these molecules across the membrane, allowing them to reach their desired location inside or outside the cell.

The correct answer is 10 to 50 um. This range of diameter is suitable for most plant and animal cells. Cells are typically measured in micrometers (um) because they are very small. The range of 10 to 50 um is consistent with the average size of cells, which can vary depending on the type of cell and the organism it belongs to.

The correct answer is removal of a phosphate group from ATP. The sodium-potassium pump is an active transport protein that moves sodium ions out of the cell and potassium ions into the cell. This process requires energy, which is obtained by breaking the high-energy phosphate bond in ATP through a process called hydrolysis. When a phosphate group is removed from ATP, it releases energy that can be used by the sodium-potassium pump to carry out its transport function.

A light microscope uses optical lenses to magnify objects by bending light rays. When light passes through the lenses, it undergoes refraction, causing the light rays to change direction. This bending of light allows the microscope to focus the light rays onto the object being observed, resulting in magnification. By manipulating the path of light, the microscope can enhance the resolution and provide a clearer image of the object.

The end products of photosynthesis include sugars. During photosynthesis, plants convert carbon dioxide and water into glucose (a type of sugar) and oxygen. This process occurs in the chloroplasts of plant cells, where sunlight is used to power the conversion of carbon dioxide and water into glucose. The glucose produced during photosynthesis is then used as a source of energy for the plant, while oxygen is released as a byproduct.

Van Leeuwenhoek's microscopes had the advantage of having lenses that were ground very precisely. This means that the lenses were made with great accuracy and attention to detail, resulting in a high level of clarity and resolution in the images produced by the microscope. The precise grinding of the lenses allowed for better magnification and a clearer view of microscopic organisms, making van Leeuwenhoek's microscopes highly effective tools for scientific observation.