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38 Cards in this Set
- Front
- Back
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"What are the structural units of all living things?" |
Cells |
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"How many cells does the human body have?" |
"50 to 100 trillion" |
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"What is a cell according to the Cell Theory?" |
"The basic structural and functional unit of living organisms." |
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"On what does the activity of an organism depend, according to the Cell Theory?" |
"The collective activities of its cells." |
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"What does the principle of complementarity dictate about cells?" |
"The biochemical activities of cells are dictated by their structure, which determines their function." |
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"What is the basis for the continuity of life, according to the Cell Theory?" |
"Continuity of life has a cellular basis." |
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"What are the four elements most cells are composed of?" |
"Carbon, Hydrogen, Oxygen, Nitrogen" |
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"What percentage of a cell's composition is water?" |
About 60% |
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"What are the three main regions or parts of a cell?" |
"Plasma membrane, Nucleus, Cytoplasm" |
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Define figure Define organs |
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"What is the primary function of the plasma membrane in a cell?" |
"It acts as a transparent barrier for cell contents." |
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"What is contained within the plasma membrane?" |
"Cell contents." |
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"What does the plasma membrane serve to separate?" |
"It separates cell contents from the surrounding environment." |
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"How are the phospholipids arranged in the fluid mosaic model?" |
"Two layers of phospholipids are arranged 'tail to tail.'" |
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"What is interspersed among the phospholipids in the fluid mosaic model?" |
"Cholesterol and proteins." |
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"What may be attached to the phospholipids, forming glycolipids in the fluid mosaic model?" |
"Sugar groups." |
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"How are the hydrophilic polar 'heads' oriented in the plasma membrane?" |
"They are oriented on the inner and outer surfaces of the membrane." |
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"Where do the hydrophobic nonpolar 'tails' form in the plasma membrane?" |
"They form the center (interior) of the membrane." |
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"What characteristic of the interior of the plasma membrane makes it relatively impermeable to most water-soluble molecules?" |
"The hydrophobic interior." |
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"What specialized functions do proteins serve in the plasma membrane?" |
"Enzymes, receptors for hormones or other chemical messengers, and transport as channels or carriers." |
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"What are glycoproteins in the plasma membrane?" |
"Branched sugars attached to proteins that abut the extracellular space." |
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"What is the glycocalyx on the cell's surface?" |
"The fuzzy, sticky, sugar-rich area on the cell's surface." |
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"How are cells bound together by the glycoproteins in the glycocalyx?" |
"They act as an adhesive or cellular glue." |
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"How do the membranes of adjacent cells fit together in cell membrane junctions?" |
"They fit together in a tongue-and-groove fashion with wavy contours." |
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"What are the types of cell membrane junctions formed, and how do they vary?" |
"Special cell membrane junctions are formed, which vary structurally depending on their roles." |
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"What does the control center of the cell contain?" |
"It contains genetic material known as deoxyribonucleic acid, or DNA." |
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"What is the primary function of DNA in the cell?" |
"It is needed for building proteins and necessary for cell reproduction." |
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"What are the three regions of the control center of the cell?" |
"Nuclear envelope (membrane), Nucleolus, Chromatin." |
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"What is the composition of the nuclear envelope?" |
"It consists of a double membrane that bounds the nucleus." |
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"What is the function of the nuclear pores in the nuclear envelope?" |
"They allow for the exchange of material with the rest of the cell." |
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"What does the nuclear envelope enclose within the nucleus?" |
"It encloses the nucleoplasm, a jellylike fluid." |
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"What is found in the nucleus and is responsible for ribosome assembly?" |
"One or more dark-staining nucleoli." |
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"What is the primary function of the nucleolus?" |
"It is the site of ribosome assembly." |
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"Where do ribosomes migrate after assembly, and what is their function?" |
"Ribosomes migrate into the cytoplasm through nuclear pores to serve as the site of protein synthesis." |
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"What is chromatin composed of?" |
"DNA wound around histones (proteins)." |
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"When is chromatin present within the nucleus?" |
"When the cell is not dividing." |
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"What does chromatin condense to form, and under what circumstance does this occur?" |
"It condenses to form dense, rodlike bodies called chromosomes when the cell divides." |
