UNIT 2 MULTIPLE CHOICE Flashcards
who is the German scientist who concluded that all PLANTS are composed of cells.
Mattias Schleiden
who is the German scientist who declared that all ANIMAL TISSUES were made up of cells?
Theodore Schwann
who is the Prussian physician that proposed that every cell came from a cell that already existed?
Rudolf Vichow
what is cell theory?
-all organisms are composed of one or more cells.
-all cells comes from preexisting cells
what is a compound light microscope?
-utilizes series of glass lenses and visible to light to magnify image
-magnifies up to 1,000 time of actual size
what is an electron microscope?
-utilizes magnetss to aim a beam of electrons at cell to produce image
-magnifies up to 500,000 times the actual size
what are the three type of electron microscopes?
-Transmission Electron Microscope (TEM)
-Scanning Electron Microscope (SEM)
-Scanning Tunneling electron Microscope (STM)
what is transmission electron microscope?
-uses magnets to aim beam of electrons to create an image
-500,00x
-used in non-living specimen
what is scanning electrom microscope?
-produces 3d image of the cell
-used in non-living specimen
what is scanning tunneling electron microscope?
can magnify LIVING cells
describe prokaryotic cell.
-simple structure
-contains plasma membrane
-no nucleus
-does not contain membrane-bound organelles
describe eukaryotic cell.
-more complex structure
-contains plasma membrane
-have nucleus
-contains membrane-bound organelles (mitochondria and/or chloroplasts)
describe plasma membrane (cell membrane).
-thin, flexible boundary between the cell and its environment
what does the plasma membrane allows?
-allows nutrients into the cell
-allows waste to leave the cell
what is selective permeability (semi-permeable)?
plasma membrane controls the movement of substances into and out of cell
what does the semi-permeable controls?
controls the amount of..
-substance entering the cell
-substance leaving the cell
what is plasma membrane composed of?
phospholipid bilayer
what does a phospholipid molecule composed of?
-glycerol backbone
-phosphate group
-two fatty acid chains
what is fluid mosaic model?
phospholipid bilayer allows other molecule to float
what are the other components of fluid mosaic model?
-proteins
-carbs
-cholesterol
what is the main role of protein in the plasma membrane?
-provide pathways for substances to enter and leave
-transmit signals inside the cell
-act as support structure
what is the main role of cholesterol in the plasma membrane?
prevents fatty acid tails from sticking together
what is the main role of carbs to the plasma membrane?
identify chemical signals
describe cilia. what is its function?
-short, numerous projections that look like hairs
-mobility
describe flagella. what is the function of flagella?
-longer and less numerous than cilia
-create movement with a whiplikw motion
what is the main function of nucleus?
control centre of the cell
what is the main function of mitochondria?
energy release
what is the main function of golgi apparatus?
packaging and secretion
what is the main function of lysosome?
digestion
where does centrioles arise from?
region of cytoplasm called centrosome
what cell structure occur in pairs and important for cell division?
centrioles
what cell structure occur in pairs and important for cell division?
centrioles
what happens to pair of centrioles during cell division?
migrate to opposite poles of the cell and produce microtubules of the spindles
what is the main function endoplasmic reticulum?
detoxification and transport
what is the main function of ribosomes?
protein construction
what is cytoplasm?
matrix that contains all of the different organelles.
cytoplasm can be seen moving called?
cytoplasmic streaming
what does phospholipid bilayer form?
majority of the membrane
when and who are the people who proposed fluid mosaic model?
1972 by J Singer and G Nicholson
what cell structure can ONLY be found in PLANTS?
chloroplasts
chloroplasts are bound by?
double membrane called chloroplast envelope
this is inside the chloroplast, described as colorless matrix?
stroma
this structure/organelle is floating in the stroma. they stack together which form?
thylakoids,granum
grana can be interconnected by tubular extensions called?
intergranal lamellae
define starch grains
act as temporary stores for carbs fromed durinh photosynthesis
what is vacuole? it is surrounded by?
large fluid filled sac, membrane called tonoplast
what is vacuole? it is surrounded by?
large fluid filled sac, membrane called tonoplast
what is the main function of vacuole?
storage site and provides support for plant cells
what is plasmodesmata?
gaps in the cell wall that allow neighbouring cells to link together
what is cell wall made of? this is located in?
-cellulose microfibrils
-polyssacharide matrix
what does cell wall provide?
strength and support and provides pathway for water
in cell diversity, what are the structures that plant cells have but animal cells are lack of?
plastids and large central vacuole
define microtubules.
hollow tubes of protein called tubulin which serves as tracks for organelle movement
define microfilaments.
made of two strands of protein molecules twisted together
what cell shape is described as a long and threadlike?
neurons (cells in the NS)
what is the function of neurons?
carry infor from areas of your body to your brain
what shape of a cell is described as round disks?
blood cells
what can blood cells do?
squeeze through tiny blood vessels
how big is a cell?
they vary in size and shape, but most celly are only aboout 25 micrometer.
what does the number of cells determine?
organism’s total size
in semi-permeable membrane, what substances can pass through?
small, uncharged molecules
in semi-permeable membrane, what substances cannot pass through?
large molecules and some particles with strong electrical charge
molecules can enter and exit a cell through?
-paasive transport
-bulk transport
-active transport
what is passive transport?
movement of particles across the cell membrane WITHOUT using energy (movement is down the concentration gradient).
what is passive transport?
movement of particles across the cell membrane WITHOUT using energy (movement is down the concentration gradient).
what are the three modes of passive transport?
-diffusion
-facilitated diffusion
-osmosis
what arrangement of concentration is in the passive transport?
high to low concentration
what is diffusion?
movement of particles from area of high concentration to an area of low concentration
diffusion is controlled by?
-temperature
-pressure
-concentration
what happens to the dynamic equilibrium of diffusion?
molecules ccontinue to move but the overall concentration remains the same
what is facilitated diffusion?
-movement of materials across plasma membtranes using proteins
-still does not require energy
-movement is from high to low concentration
what is the difference between channel protein and carrier protein?
-CHANNEL PROTEIN interact with solute to be transported
-CARRIER PROTEIN is like a lock and key that only bind specific molecule
what factors can influence the rate of diffusion?
-temperature
-state of the solvent
-size of the molecules
-steepness of diffusion gradient
-permeability
-membrane structure
how does temperature affect rate of diffusion?
increases speed of diffusion
how does state of solvent affect rate of diffusion?
diffusion occurs faster in gases than in liquids and much faster in liquids than in solids
how does state of solvent affect rate of diffusion?
diffusion occurs faster in gases than in liquids and much faster in liquids than in solids
how does size of molecules affect rate of diffusion?
larger molecule, the slower it diffuse
how does steepness of diffusion gradient affect rate of diffusion?
greater concentration gradient, the faster it diffuse
what is osmosis?
diffusion of water across a semi-permeable membrane
moves from high to low concentration
water moves from areas of low solute (high H2O) concentration to high solute (H2O) concentration
what is osmosis?
diffusion of water across a semi-permeable membrane
moves from high to low concentration
water moves from areas of low solute (high H2O) concentration to high solute (H2O) concentration
what are the three types of solutions?
-isotonic
-hypotonic
-hypertonic
what is active transport?
movement of particles across the cell membrane USING ENERGY.
what is the concentration gradient in active transport?
low to high concentration
what type of active transport pump moves three na+ ions OUT of the cell and two k+ INTO the cell?
NA+/K+ ATPase pump (sodium-potassium pumps)
what is the result of NA+/K+ ATPase pump?
electrical gradient
what is the role of carrier proteins in active transport?
pumps the use energy (ATP) to move ions and molecules
what is bulk transport?
large molecules, food, and other substances are packaged in a membrane-bound sacs and moved across membrane
what ios endocytosis?
endo (indoor)-folds into pouch that encloses particles
what is the difference between phagocytosis and pinocytosis?
-PHAGO-cell engulfs FOOD particles
-PINO-cell engulfs drop of a LIQUID
what is exocytosis?
secretion of materials OUT of the plasma membrane
what is the function of ocular eyepiece?
the lens you look through when viewing an object
what is the function of ocular tube?
hollow tube that supports the ocular and allow light to pass from objectives to lens
what is the function of the arm (c-shaped support)?
used for carrying the instrument
what is the function of the revolving nosepiece?
contains 2-4 lenses of different magnifications and is able to rotate
what is the function of the objective lenses?
complex lenses positioned above the slide to view object.
-shortest is the low-power
-longest if the high-power
what is the function of the coarse focusing knob?
used to roughly focus the lens on an object (ONLY FOR LOW-POWER)
what is the function of the fine focusing knob?
moves stage or ocular tube a small distance (used for HIGH-POWER)
what is the function of the stage (with clips)?
supports the slide, opening permits light to illuminate the object on the slide
what is the function of the iris (or disk) diaphragm and condenser ?
regulates the amount of light reaching the slide
what is the function of the light source (lamp/mirror)?
reflects light through the hole in the stage and must be adjusted for max light
what is the function of the inclination joint?
moveable joint found on upright microscopes
what is the function of the inclination joint?
moveable joint found on upright microscopes
what is the function of the base?
supports the weight of microscope
what is energy?
ability to do work
what is thermodynamics?
study of flow and transformation of energy in the universe
