Cells

Question 1

What are the 2 types of microscope?

Answer 1

. Light
. Electron

Question 2

What are the characteristics of a light microscope?

Answer 2

. Uses light & lenses to magnify objects

. Best possible magnification with good resolution is X1000

Question 3

What are the characteristics of an electron microscope?

Answer 3

. Uses electrons instead of light

. Detailed & high magnification (X200000 to X2000000)

Question 4

What are the 2 types of electron microscope?

Answer 4

. Transmission electron microscope (TEM)

. Scanning electron microscope (SEM)

Question 5

What is a “micrograph”?

Answer 5

Photos of specimens taken down the microscope

Question 6

What 2 things are needed to work out the magnification of the image?

Answer 6

. The size of image
. The actual size of specimen

Question 7

What is the formula for magnification?

Answer 7

Magnification = Imagize size / actual size

Question 8

Define “magnification”

Answer 8

The number of times greater the image is than the specimen

Question 9

Define “resolution”

Answer 9

The ability to distinguish between two points on an image

Question 10

What are the 4 sample stains?

Answer 10

. Gram staining
. Eosin
. Iodine
. Methylene blue

Question 11

What colour does gram-positive bacteria produce?

Answer 11

Purple

Question 12

What colour does gram-negative bacteria produce?

Answer 12

Red

Question 13

What does eosin do?

Answer 13

Stains red blood cells & cell membranes pink or red colour

Question 14

What does iodine do?

Answer 14

Stains starch blue/black

Question 15

What does methylene blue do?

Answer 15

Stains nuclei & chromosomes blue

Question 16

What is “histology”?

Answer 16

The microscopic study of the structure, composition & function of biological tissues

Question 17

What are the 3 steps to preparing a slide?

Answer 17

. Add a thin slice of specimen onto a clean microscopic slide

. Add a drop of water or stain onto specimen

. Take a clean cover slip, slowly lower it onto specimen, avoiding bubbles

Question 18

What are the 5 steps to setting up a microscope?

Answer 18

. Switch it on

. Check condenser lens is below the stage

. Put objective lens on low power

. Move stage to highest position

. Adjust light to medium

Question 19

What are the 7 steps to using the microscope?

Answer 19

. Open the clip

. Slide microscope slide to back of stage

. Center specimen over lens

. Look through lens, focus specimen

. Use next highest objective lens & refocus using fine focus

. Continue & go on to next highest lens

. Adjust light to improve contrast

Question 20

What are the 6 steps to cleaning up the microscope?

Answer 20

. Remove slide

. Rotate lens to lowest power

. Move stage to centred position (its clean & dry)

. Turn off light & power

. Wrap the cord

. Carry with one hand on arm & one on base of microscope

Question 21

What is the difference between a TEM microscope & a SEM microscope?

Answer 21

SEM microscopes use 3D images, TEM microscopes use 2D images

Question 22

What is a ‘cell’?

Answer 22

The basic and fundamental unit of life that possesses a highly organised structure that enables it to carry out vital functions

Question 23

What are the 2 types of cell?

Answer 23

. Prokaryotic
. Eukaryotic

Question 24

What are the 2 types of eukaryotic cell?

Answer 24

. Animal
. Plant

Question 25

What type of cell has a defined nucleus?

Answer 25

Eukaryotic

Question 26

Where does the genetic material get contained in a prokaryotic cell?

Answer 26

Cytoplasm

Question 27

What is the nucleoid in a prokaryotic cell?

Answer 27

Area containing DNA

Question 28

What are plasmids in a prokaryotic cell?

Answer 28

Small circles of additional DNA

Question 29

What is the function of the nucleus?

Answer 29

. Coordinates all the cell’s activities . Stores DNA

Question 30

What is the function of the nucleolus?

Answer 30

. Stores RNA . Production of ribosomes

Question 31

What is the function of mitochondria?

Answer 31

. Produces ATP for respiration

Question 32

What is the function of the golgi apparatus?

Answer 32

. Works with ER containing ribosomes . Formation & storage of proteins

Question 33

What is the function of lysosomes?

Answer 33

. Contains enzymes that digest waste products & debris . Some cells have conventional lysosomes that contain secretory products, these are known as secretory lysosomes

Question 34

What is the function of the plasma membrane?

Answer 34

. Encloses the cells contents

Question 35

What is the function of sER?

Answer 35

. (smooth endoplasmic reticulum) . Production & storage of lipids & steroids

Question 36

What is the function of rER?

Answer 36

. (rough endoplasmic reticulum) . Contains ribosomes that form & store proteins

Question 37

What is the function of cilia?

Answer 37

. (short microscopic hair-like structures) . Moves fluid past cells surface, helps cell to move

Question 38

What is the function of the cytoskeleton?

Answer 38

. Maintains cells shape . Made of microtubules (position organelles), actin filaments (cytokinesis & cell movement), intermediate filaments (strength & support)

Question 39

What is the function of ribosomes?

Answer 39

. Made of two subunits that join together to manufacture proteins . 80s ribosomes in eukaryotic cells . 70s ribosomes in prokaryotic cells

Question 40

What is the function of centrioles?

Answer 40

. Two hollow cylinders arranged at right angles to form centrosomes . These form spindles during cell division

Question 41

What is the function of peroxisomes?

Answer 41

. Small vesicles containing oxidative enzymes . Help remove toxic substances

Question 42

What is the model called of the plasma membrane?

Answer 42

The fluid mosaic model

Question 43

What is the main component of the plasma membrane?

Answer 43

Phospholipids

Question 44

What does the hydrophilic head do in the fluid mosaic model?

Answer 44

Is attracted to water

Question 45

What does the hydrophobic tail do in the fluid mosaic model?

Answer 45

It repels water

Question 46

What is the bilayer of the fluid mosaic model?

Answer 46

. Contains many proteins . Some integral . Some peripheral . Some attached to long carbohydrate chains . Plasma membrane contains cholesterol

Question 47

What does integral mean in the bilayer of the fluid mosaic model?

Answer 47

Crosses the membrane

Question 48

What does peripheral mean in the bilayer of the fluid mosaic model?

Answer 48

On one side of the membrane

Question 49

What are phospholipids that are attached to chains called?

Answer 49

Glycolipids

Question 50

What are proteins that are attached to chains called?

Answer 50

Glycoproteins

Question 51

What do phospholipids do in the plasma membrane?

Answer 51

Controls what goes in and out the cell

Question 52

What does the integral protein cell do in the plasma membrane?

Answer 52

Transports molecules in and out the cell

Question 53

What do glycolipids & glycoproteins do in the plasma membrane?

Answer 53

Cell recognition by signalling and by receptors

Question 54

What does the peripheral protein do in the plasma membrane?

Answer 54

Enzymes

Question 55

What does cholesterol do in the plasma membrane?

Answer 55

Maintains the stability of the cell

Question 56

What are the functions of the plasma membrane itself?

Answer 56

. Partially permeable - controlls the transport of molecules in & out the cells . Keeps cell contents separate from outside environment . Allows other cells to recognise the cell as part of the body . Allows cells to signal to each other . Allows molecules (hormones & drugs) to bind to receptors in membrane . Hold components of some chemical reactions (enzymes) in place