| A | B |
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| What are the basic units of structure and function in living things? | Cells are the basic units in living things. |
| Who was Anton van Leeuwenhoek? | He was a Dutch biologist who is given credit for developing the first microscope. |
| Who is credited with first using the word "cell" to describe what was seen under his microscope? | An Englishman, Robert Hooke, called the tiny chambers seen in pieces of cork "cells". |
| What important structure did Robert Brown (Scottish) scientist observe? | He saw a dark structure near the center of the cell; we now call this the "nucleus". |
| What statement did Matthias Schleiden (German botanist) make that was important? | Schleiden said that all plants are made of cells. |
| Schwann expanded Schleiden's statement regarding cells; what did he say? | Schwann discovered that all animals are made of cells (Schleiden said all plants were made of cells). |
| Rudolf Virchow (German physician) added more to the developing theory of cells; what did he add to it? | Virchow said that ALL cells come from the division of cells that already exist. |
| State the cell theory. | (1) All living things are composed of cells. (2) Cells are the basic units of structure & function in living things; (3) All cells come from preexisting cells. |
| To what group do the smallest organisms belong? | The smallest cells belong to the Mycoplasma group (about 0.2 micrometers in diameter). |
| What is the size range of most cells? | Most cells are between 5-50 micrometers in diameter. |
| What are the 3 basic structures that are common to the cells of animals, plants, and related organisms? | (1) cell membrane (outer boundary of cell); (2) nucleus (control center); (3) cytoplasm (material between cell membrane & nucleus). |
| What functions does the cell membrane perform? | (1) Regulates what enters & leaves the cell (food & water in; wastes out); (2) helps protect & support the cell; (3) communicates with other cells. |
| What is the most important type of molecule making up the cell membrane? | A bilayer (double) of lipids are the most important molecule in the cell membrane. |
| What functions do proteins perform in the cell membrane? | (1) Free-moving ones serve as channels through which molecules can pass; (2) others are like small pumps that push molecules from 1 side of the membrane to the other. |
| Why are carbohydrates important to the cell membrane? | Carbohydrates attach to proteins or lipids on the surface of cell membranes; they act as chemical identification cards that permit cells to recognize & interact with each other. |
| Where is a cell wall located? | In plants, algae, and some bacteria, the cell wall surrounds the cell membrane (protecting & supporting). |
| Primary cell walls are made of cellulose; how does that help? | Cellulose is elastic, so the cell can stretch as the cell grows. |
| In woody stemmed plants, what purpose does lignin serve? | In the secondary wall, lignin makes the cellulose more rigid (stiffer). (173) |
| Describe the nuclei of prokaryotes & eukaryotes. | Prokaryotes DO NOT have nuclei; the nucleus of eukaryotes is pictured on pg. 93. (nuclear envelope; nucleolus; nuclear pores; inner & outer membranes. |
| What is cytoplasm? | Cytoplasm is the region between the nucleus & cell membrane. |
| What is an organelle? | Organelle = a tiny structure that performs a specialized function in the cell. Each has its own job to perform; they help maintain the cell's life. |
| What are mitochondria? | Mitochondria are organelles that change chemical energy stored in food into compounds that can be used by the cell. |
| What are the 2 special membranes of mitochondrion? | Outer membrane surrounds the organelle; inner membrane has numerous folds that increase the surface area of the mitochondrion (see picture, pg. 175). |
| Where are chloroplasts found? | Chloroplasts are found ONLY in plant cells & algae. (picture: pg. 175) |
| What are ribosomes? | Ribosomes = the organelles in which proteins are manufactured. They are made up of RNA and protein. |
| What is ER? | ER = endoplasmic reticulum; these are a series of sacs found in many cells. They move materials throughout the inside of the cell. |
| What types of ER are there? | Smooth ER and rough ER. (see pg. 177). |
| What is the Golgi apparatus? | It's an organelle that modifies, collects, packages, and distributes molecules made at one location of the cell and used at another. (see 178) |
| What is endocytosis? | The process by which materials that are too large to pass through cell membranes get into the cell (pg. 189). |
| What function do lysosomes perform? | Lysosomes are small structures containing chemicals & enzymes needed for digesting materials in the cell; they also break down useless organelles. They're formed by the Golgi apparatus. |
| What types of cells do not have lysosomes? | Plant cells lack lysosomes. |
| What do vacuoles do? | Vacuoles store materials like water, salts, proteins, & carbohydrates. |
| What is the endosymbiotic theory? (180) | It's a theory about the evolving of prokaryotes into mitochondria and into chloroplasts (see your book). |
| What is the cytoskeleton of the cell? | Cytoskeleton = framework of cell; made up of filaments & fibers that support the cell and move it. (Picture on 181) |
| How do chloroplasts produce energy and food? | They use energy from the sun to produce food, which contains energy. |
| How do mitochondria produce energy? | Mitochondria use cellular respiration to produce energy (found in chemical bonds in ATP). |
| What is diffusion? (review) | Diffusion = process by which molecules of a substance move from areas of higher concentration to areas of lower concentration. |
| What is meant by "equilibrium point"? (review) | Equilibrium point = the point at which concentrations of substances on both sides of a membrane are the same; there is no additional change in concentration. |
| What does "impermeable" mean? | Impermeable means that things cannot pass across a membrane. |
| What is meant by "selectively permeable"? | Selectively permeable = when a membrane allows some substances pass through, but doesn't let others pass through the membrane. |
| What is osmosis? | Osmosis = the diffusion of water molecules through a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration. |
| What does osmotic pressure do to the movement of water? | Osmotic pressure tends to move water across membranes from a more dilute solution into a more concentrated solution. |
| How can osmotic pressure cause problems for a cell? | Cytoplasm is filled with salts, sugars, proteins, etc.; so, it usually has a much lower concentration of water than is found in fresh water. If the cell is surrounded by fresh water, the water will move into the cell freely (osmotic pressure); the cell will swell and burst. |
| How long does osmosis continue? | Osmosis continues until equilibrium is reached.(185-6) |
| How do cells handle free permeability to water? | (1) Cells may be bathed in fluids that have concentrations of dissolved materials equal to the cells themselves; (2) cell walls protect expansion of the cell (but may damage it); (3) some cells have a mechanism to pump out water. |
| What is facilitated diffusion? | Facilitated diffusion = diffusion of materials across a cell membrane assisted by carrier molecules. (187) |
| What does a carrier protein do? | Carrier proteins carry (transport) molecules across a membrane in the direction of lowest concentration. This happens ONLY if a concentration difference exists across the membrane. |
| What happens in active transport? | Active transport: it requires energy to move material across a cell membrane AGAINST a concentration difference. |
| What are the 2 types of active transport? | (1) Individual molecules are carried through membrane-associated pumps (102); (2) Large amounts of material are carried through movements of the cell (endocytosis). |
| What type of active transport do amebas use to take in food? | Phagocytosis: extensions of cytoplasm surround & engulf large particles for the amebas to use as food. |
| What is pinocytosis? (in section 7.3) | Pinocytosis: the cell takes up liquid from its surrounding; tiny pockets form along the cell membrane, fill with liquid, and form vacuoles in the cell. |
| What happens in exocytosis? (section 7.3) | In exocytosis, material is sent out of the cell (104). |
| What is meant by cell specialization? | Cell specialization = cells are often uniquely suited to perform a particular function within the organism. (i.e., some move the cell; some react to the environment; some make specific products.) |
| What is the chief function of the pancreas? | The pancreas has cells that are specialized to produce digestive enzymes--many of which are involved in protein synthesis. |
| What are the 2 different parts of light-sensitive cells? | (1) mitochondria are in the lower of the cell (5 times greater than normally found); (2) small flattened membranes are stacked (like pancakes) in the upper part. |
| What are the 4 levels of organization found in multicellular organisms? | Cells, tissues, organs, & organ systems. |
| Name 4 types of tissue. | muscle, epithelial, nerve, and connective tissues |
| What is an organ? | Organ = a group of tissues that work together to perform a specific function. |
| What is an organ system? | A group of organs that work together to perform a specific function is an organ system. |
| What is a unicellular organism? | It is a single-celled organism that can do everything a living thing can do: grow, respond to the environment, transform energy, reproduce. |
| What is cell specialization? | This refers to the fact that cells throughout an organism can develop in different ways to perform different tasks. |
| What specialized function do red blood cells do? | They transport oxygen throughout the body. |
| What specialized function does the pancreas do? | It produces enzymes that make it possible to digest food; pancreatic cells also export protein. |
| What cytoskeletal protein works with actin microfilaments to help your muscles move? | The protein is myosic. |
| What specialized functions do guard cells have? | They monitor the plant's internal conditions, changing their shape according to those conditions (i.e., how the stomata functions). |
