click below
click below
Normal Size Small Size show me how
Chapter 6 Biology
A Tour of the Cell
Question | Answer |
---|---|
What is the definition of magnification? | ratio of image to its actual size |
What is the definition of resolution? | measure of clarity of image, the measure of distinguishing two points that are very close to each other |
What is NOT part of a Prokaryotic cell? a.ribosomes b.DNA c.a cell wall d.a plasma membranee.an endoplasmic reticulum | e.an endoplasmic reticulum |
What is the definition of free ribosomes? | are present in the cytosol |
Where are bound ribosomes located? | they're attached to the outer surface of the endoplasmic reticulum (ER)or the nuclear envelope |
What are the main functions that Smooth ER does? | synthesizes lipids, metabolizes carbs, stores calcium, & detoxifies poison |
What are the main functions that Rough ER does? | produces proteins and membranes, makes secretory protein & is a membane factory for the cell |
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? a.steroids b.starches c.lipids d.proteins | d.proteins |
Explain well cell fractionation is a useful technique. | it takes cells apart and separates the major organelles from one another. The isolated organelles can be used for determination of function. This would be the determination of proteins, lipids, enzyme activities, etc. |
A primary objective of cell fractionation is to what? a.determine the size of various organelles b.identify the enzymes outside the organelles c.view the structure of cell membranes d.separate major organelles so that their funtions can be determined | d.separate major organelles so that their functions can be determined |
What does the endomembrane system regulate? | the protein traffic and performs metabolic functions in the cell |
What are the components of the endomembrane system? | nucleus and nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, & plasma membrane |
What is the role of the mitochondria? | to change energy from one form to another, the site of cellular respiration, in nearly all eukaryotic cells, has two membranes-smooth outer membrane & an inner membrane folded into cristae |
What can be found in only plants and algae and are the sites of photosynthesis? | Chloroplasts |
What contains green pigment chlorophyll as well as enzymes and other molecules that function in photosynthesis? | Chloroplast |
The Chloroplast structure includes what? | thylakoids, membranous sacs, stroma & the internal fluid |
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? | a change in the shape of the nucleus |
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?a.contractile vacuole b.ribosome c.Smooth ER d.lysosome e.mitochondrion | c.Smooth ER |
Which structure is the site of the synthesis of proteins that may be exported from the cell? a.plasmodesmata b.rough ER c.golgi vesicles d.tight junctions e.lysosomes | b.rough ER |
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which organelle would this be? | lysosome |
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? a.nuclear envelope b.rough ER c.smooth ER d.golgi apparatus | c.smooth ER |
What organelle takes up much of the volume of a plant cell? | vacuole |
Which organelle is one of the main energy transformers of cells? | mitochondrion |
Which structure is common to plant and animal cells? | mitochondrion |
What does a perioxisome do? | it produces hydrogen peroxide and converts it to water |
What are the three types of vacuoles? | food, contractile, and central vacuoles |
What is a food vacuole? | it's formed by phagocytosis. that means it's a process in which cell engulfs smaller organisms or other objects |
Where can contracile vacuole be found and what does it do? | in many freshwater protists, and it pumps excess water out of cells |
Where can a central vacuole be found and what does it do? | in many mature plant cells, and it holds organic compounds and water |
What is the definition of the cytoskeleton? | a network of fibers that organize structures and activities in the cell. It extends throughout the cytoplasm. |
What is the function of the cytoskeleton? | to organize the cell structures and activities and anchor many organelles, play a role in support, motility, and regulation of the cell, Also helps to maintain its shape. |
What is the definition of a microtubule? | it's the thickest of the three components of the cytoskeleton. |
What is the function of a microtubule? | the shaping of the cell, guiding movement of organelles, and separating chromosomes during cell division |
What is the definition of a microfilament and what else might it be called? | it's the thinnest component of the three and is also called actin filament |
What is the difference between the rods of the microtubule and the microfilament? | the microtubule are hollow and the other is solid |
How big is the Intermediate filament and what do they support? | larger than microfilament but smaller than microtubule and they support cell shape and fix organelles into place |
Of the three:microtubule, microfilament, and intermediate filament, which is the most permanent cytoskeleton fixture? | Intermediate filament |
What does cilia and flagella do? | are protrusions from some cells that aid in cellular locomotion. They are formed from specialized groupings of microtubules called basal bodies. |
If the protrusions are short and numerous they are termed what? | cilia |
If they are longer and less numerous (usually only one or two) they are termed what? | flagella |
What are some distinguishing characteristics that cilia and flagella has? | have a core composed of microtubules connected to the plasma membrane arranged in what is known as a 9 + 2 pattern. |
Where can cilia and flagella be found? | the sperm of many animals, algae, and even ferns |
This structure may have multiple layers like: a primary cell wall-relatively thin and flexible, a middle lamella-thin layer between primary walls of adjacent cells, and secondary cell wall-added between the plasma membrane and the primary cell wall | plant cell wall |
What is the purpose of the structure of the plant cell wall? | it protects the cell, maintains its shape, and prevents excessive uptake of water |
Intercellular junctions facilitate what type of contact and how? | neighboring cells in tissues, organs, or organ systems often adhere, interact and communicate through direct physical contact |
What has plasmodesmata and what does it do? | plants and it allows water and small solutes (and sometimes proteins and RNA) can pass from cell to cell |
Name the Intercellular junctions in animals. | tight junctions, desmosomes, and gap junctions |
Which junction is this-membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid. | tight junctions |
What junction is this-anchoring juction-fasten cells together in strong sheets | desmosomes |
What junction is this-communicating junction-provide cytoplasmic channels between adjacent cells | gap junctions |