Chapter 4

What are the fundamental units of life according to cell theory?

Cells are the basic units of life.

What are the three main components of the cell theory?

1. Cells are basic units of life, 2) All living organisms are made of cells, 3) All cells come from preexisting cells.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells lack membrane-enclosed internal compartments like a nucleus.

What is the role of ribosomes in a cell?

Ribosomes synthesize proteins by assembling amino acids.

What is the primary function of lysosomes?

Lysosomes contain digestive enzymes to break down large biomolecules and worn-out organelles.

What is the structure of the eukaryotic plasma membrane?

It consists of a phospholipid bilayer with embedded proteins.

What is the major difference between rough and smooth endoplasmic reticulum?

Rough ER has ribosomes on its surface and modifies proteins, while Smooth ER synthesizes lipids and has few or no ribosomes.

What are chloroplasts responsible for in plant cells?

Chloroplasts are the sites of photosynthesis in plants.

What are tight junctions and where are they found?

Tight junctions are watertight seals between animal cells, found in epithelial cells lining internal organs and cavities.

What is the function of the central vacuole in plant cells?

The central vacuole helps regulate water concentration and contributes to cell expansion.

What are the three components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

What is endosymbiosis?

A hypothesis that mitochondria and chloroplasts originated as independent prokaryotic organisms that became part of eukaryotic cells.

What is the function of mitochondria?

Mitochondria are known as the powerhouse of the cell, generating ATP through cellular respiration.

What is a cell membrane?

The cell membrane is a protective layer that controls the movement of substances in and out of the cell.

What are the differences between plant and animal cells?

Plant cells have a cell wall and chloroplasts, while animal cells do not.

What is the function of the nucleolus?

The nucleolus is responsible for producing ribosomes within the nucleus.

What is a stem cell?

A stem cell is an undifferentiated cell that has the potential to develop into different cell types.

What role do enzymes play in cells?

Enzymes act as catalysts to speed up chemical reactions in the cell.

What is apoptosis?

Apoptosis is the process of programmed cell death that helps eliminate damaged or unnecessary cells.

What is the function of the Golgi apparatus?

The Golgi apparatus modifies, sorts, and packages proteins for secretion or delivery to other organelles.

What is differentiation in cells?

Differentiation is the process by which a cell becomes specialized to perform a specific function.

What is the role of transport proteins in the cell membrane?

Transport proteins assist in the movement of substances across the cell membrane.

What are enzymes?

Enzymes are biological catalysts that speed up chemical reactions in living organisms.

What is the function of DNA?

DNA stores genetic information used in the development and functioning of all living organisms.

What are the two main types of cells?

The two main types of cells are prokaryotic and eukaryotic.

What is cellular respiration?

Cellular respiration is the process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.

What is the function of the cell wall?

The cell wall provides structural support and protection to plant cells and some prokaryotic cells.

What is a virus?

A virus is a microscopic infectious agent that can replicate only inside the living cells of an organism.

What are the components of the cell membrane?

The cell membrane is composed of a phospholipid bilayer, proteins, cholesterol, and carbohydrates.

What is osmosis?

Osmosis is the diffusion of water across a selectively permeable membrane.

What is the main function of chlorophyll?

Chlorophyll absorbs light energy, primarily from the sun, to convert carbon dioxide and water into glucose during photosynthesis.

What is the purpose of mitosis?

Mitosis is the process of cell division that results in two genetically identical daughter cells.

What are ribosomes made of?

Ribosomes are composed of ribosomal RNA (rRNA) and proteins.

What is photosynthesis?

Photosynthesis is the process by which green plants and some other organisms convert light energy into chemical energy in the form of glucose.

What is a lipid?

Lipids are a group of hydrophobic organic molecules, including fats and oils, that store energy and make up cell membranes.

What is diffusion?

Diffusion is the passive movement of particles from an area of high concentration to an area of low concentration.

What is the role of the plasma membrane?

The plasma membrane regulates what enters and exits the cell, maintaining homeostasis.

What are carbohydrates?

Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen, and are a primary source of energy for living organisms.

What is the function of the cytoplasm?

Cytoplasm is the gel-like substance within the cell where organelles are suspended and metabolic processes occur.

What are microtubules?

Microtubules are thin, hollow tubes that are part of the cytoskeleton and help maintain cell shape, transport materials, and enable cell division.

What is the difference between an autotroph and a heterotroph?

Autotrophs produce their own food (e.g., plants), while heterotrophs obtain food from other organisms.

What is RNA?

RNA (ribonucleic acid) is a molecule that plays roles in coding, decoding, regulation, and expression of genes.

What is the function of the endoplasmic reticulum?

The endoplasmic reticulum is involved in protein and lipid synthesis; it comes in two forms: rough (with ribosomes) and smooth (without ribosomes).

What are the phases of the cell cycle?

The cell cycle consists of interphase (G1, S, G2) and mitotic phase (mitosis and cytokinesis).

What is the function of the vesicles?

Vesicles are small membrane-bound sacs that transport materials within the cell.

What is a muscle cell's primary function?

Muscle cells primarily function to contract and enable movement.

What role do lysosomes play in the cell?

Lysosomes digest excess or worn-out organelles, food particles, and engulfed viruses or bacteria.

What are ion channels?

Ion channels are proteins that help maintain cell potential by allowing the selective passage of ions across the membrane.

What is the function of the nucleoid region in prokaryotic cells?

The nucleoid region is where the DNA is located in prokaryotic cells, as they lack a defined nucleus.

What is the role of the cytoskeleton?

The cytoskeleton provides structural support, shapes the cell, and facilitates movement.

What is chromatin?

Chromatin is a complex of DNA and proteins that forms chromosomes within the nucleus.

What are the types of connective tissue?

Connective tissue types include loose connective tissue, dense connective tissue, cartilage, bone, and blood.

What is the role of aquaporins?

Aquaporins are channel proteins that facilitate the transport of water across cell membranes.

What processes occur during interphase?

During interphase, the cell grows, duplicates its DNA, and prepares for division.

What is a gamete?

A gamete is a reproductive cell (sperm or egg) that contains half the genetic material of somatic cells.

What is the role of transcription in protein synthesis?

Transcription is the process where DNA is copied into messenger RNA (mRNA), which carries genetic information to ribosomes.

What does ATP stand for, and what is its function?

ATP stands for adenosine triphosphate and is the primary energy carrier in all living organisms.

What are stem cells?

Stem cells are undifferentiated cells with the ability to develop into various specialized cell types.

What is the difference between active and passive transport?

Active transport requires energy to move substances against their concentration gradient, while passive transport does not.

What is the function of transport vesicles?

Transport vesicles move molecules between different compartments within the cell.

What is the purpose of the extracellular matrix?

The extracellular matrix provides structural and biochemical support to surrounding cells.

What is the role of the Golgi apparatus in protein processing?

The Golgi apparatus modifies, sorts, and packages proteins before they are sent to their destination.

What are vaccines and how do they work?

Vaccines stimulate the immune system to recognize and combat pathogens, providing immunity against specific diseases.

What do neurotransmitters do?

Neurotransmitters transmit signals across synapses from one neuron to another.

What is the role of the cytosol?

Cytosol is the fluid portion of the cytoplasm where metabolic reactions occur.

What is the function of the plasma membrane's phospholipid bilayer?

The phospholipid bilayer forms the basic structure of the plasma membrane, creating a barrier between the cell's interior and its external environment.

What is chromosomal packaging?

Chromosomal packaging is the process by which DNA is organized and condensed into chromosomes for cell division.

What is the primary function of red blood cells?

The primary function of red blood cells is to transport oxygen from the lungs to the body's tissues and return carbon dioxide to the lungs.

What is the role of cilia and flagella?

Cilia and flagella are hair-like structures that aid in movement of cells or movement of fluids across cell surfaces.

What are phagocytes?

Phagocytes are immune cells that engulf and digest foreign particles or pathogens.

What occurs during meiosis?

Meiosis is a type of cell division that reduces the chromosome number by half, producing four genetically diverse gametes.

What is the role of ion pumps?

Ion pumps are membrane proteins that use ATP to move ions against their concentration gradients.

What is a phenotype?

A phenotype is the observable physical and physiological traits of an organism, resulting from the expression of its genotype.

What is gene expression?

Gene expression is the process by which information from a gene is used to synthesize a functional gene product, typically a protein.

What is apoptosis?

Apoptosis is programmed cell death that helps eliminate damaged or unnecessary cells.

What does the term 'biodiversity' refer to?

Biodiversity refers to the variety of life in a particular habitat or ecosystem.

What is a prokaryotic cell?

Prokaryotic cells are single-celled organisms that lack a nucleus and membrane-bound organelles.

What is endocytosis?

Endocytosis is the process by which cells internalize substances from their external environment.

What is the function of the rough endoplasmic reticulum?

The rough endoplasmic reticulum synthesizes and processes proteins, aided by attached ribosomes.

What is the primary role of epithelial tissue?

Epithelial tissue forms protective barriers and is involved in absorption, secretion, and sensation.

What is the central dogma of molecular biology?

The central dogma describes the flow of genetic information from DNA to RNA to protein.

What is a pathogen?

A pathogen is a microorganism that can cause disease.

What are the phases of mitosis?

The phases of mitosis are prophase, metaphase, anaphase, and telophase.

What is cell specialization?

Cell specialization refers to the process by which generic cells develop and differentiate into specific cell types with distinct functions.

What is the function of the vacuole in plant cells?

The vacuole stores nutrients and waste products and helps maintain turgor pressure.

What is a trophic level?

A trophic level is a step in a food chain representing organisms that share the same function in ecosystem dynamics.

What is the difference between primary and secondary succession?

Primary succession occurs in lifeless areas, while secondary succession occurs in areas where an ecosystem has previously existed.

What role do hormones play in the body?

Hormones are chemical messengers that regulate physiological processes such as growth, metabolism, and reproduction.