Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A level Biology > Cells > Flashcards

Cells Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is magnification ?

A

the number of times larger the image is compared to the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is resolution ?

A

the closest two points can be and still be distinguished as separate, giving the clarity of the image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

magnification =

A

image size/object size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how many nano / micro meters in a mm ?

A

nano - 1x10’6

micro - 1x10’3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the light microscope

A
  • uses light
  • max resolution is .2 micrometers
  • max magnification is x1500
  • consists of 2 glass lenses (eyepiece and objective)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where is the image created from the microscope?

A

retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what limits the magnification of the light microscope?

A

wavelength of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the laser scanning confocal microscope

A
  • use laser beams to scan fluorescent dyed specimen
  • laser causes dye to give off light, which is focused through a pinhole onto a detector (hooked to a comp), generating an image
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why is a laser scanning confocal microscope better than a light microscope?

A

pinhole means any out-of-focus light is blocked, producing a clearer image
also can look at objects at different depths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are prokaryotic cells ?

A

small simple cells that belong to single - celled organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are eukaryotic cells ?

A

complex cells that belong to mulit - cellular organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

function of sap vacuole ?

A

storage space for salts / sugars / proteins and waste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

function of middle lamella ?

A

cements 2 adjoing cells together at cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

function of plasmodesma ?

A

channel through cell wall that allows molecules and substances through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

function of mitochondrion ?

A

site of aerobic respiration, where ATP is produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

function of ribosome ?

A

site of protein production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

function of rough endoplasmic recticulum ?

A

folds and processes proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

function of smooth endoplasmic recticulum ?

A

synthesises and processes lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

function of golgi body ?

A

processes and packages new lipids / proteins

makes lysosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

function of lysosome ?

A

contains digestive enzymes to digest invading cells or break down worn out components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

function of centriole ?

A

involved with chromosome separation during cell division

22
Q

function of spindle ?

A

forms protein structure that divides the genetic material in a cell

23
Q 
function of nuclear membrane ?
(a.k.a. nuclear envelope)
A

membrane around nucleus that keeps nucleoplasm contained

24
Q

function of nuclear pore ?

A

allows transport of molecules across nuclear membrane

25
Q

function of microvillus ?

A

increases surface area for absorption and secretion functions

26
Q

function of cilium ?

A

moves substances along the cell surface

27
Q

function of nucleolus ?

A

makes ribosomes

28
Q

function of vesicle ?

A

transports substances in and out of cell and between organelles

29
Q

describe the process of (out-of-cell) protein production

A
  • ribosomes make proteins
  • proteins folded / processed in rough ER
  • transported to golgi body in vesicles
  • further processing in golgi body
  • vesicles transport proteins to surface
  • proteins excreted
30
Q

whats the difference with in-cell protein production ?

A

proteins made at free ribosomes

31
Q

what is the cytoskeleton ?

A

network of protein threads in the cytoplasm, arranged as micro filaments (solid strands) and micro tubules (cylinders)

32
Q

functions of the cytoskeleton :

A
  • supports organelles
  • strengthens and holds cell’s shape
  • responsible for movement of materials
  • can cause cell to move, e.g. cilia and flagella
33
Q

differences of prokaryotes (P) and eukaryotes (E)

7 differences

A
  • E have larger cells
  • E DNA is linear / P DNA is circular
  • E have a nucleus
  • P have polysaccharide cell walls / E have cellulose or chitin
  • P have less organelles and no membrane-bound organelles
  • E have larger ribosomes
  • P have flagella made of protein flagellin in helix / E made of microtubule proteins arranged in 9+2
34
Q

what differences are there between and electron microscope and a light microscope?

A

electron microscope uses electrons to form an image

they have higher resolution (so have higher magnification)

35
Q

Describe Transmission Electron Microscopes

A

Uses electromagnets to focus a beam of electrons through the specimen. Denser parts absorb more electrons, making them darker.
Good because provide high resolution but only used on thin specimens.

36
Q

Describe Scanning Electron Microscopes

A

Scans a beam of electrons across a specimen, knocking off electrons which are gathered in a cathode ray tube to form an image.
Can be 3D but lower res than TEMs

37
Q

what is the res of all 3 microscopes ?

A

LM : 0.2 micro m
TEM : 2x10’-4 micro m
SEM : 2x10’-3 micro m

38
Q

what is the magnification of all 3 microscopes ?

A

LM : x 1500
TEM : > x 1,000,000
SEM : < x 500,00

39
Q

7 stages of preparing a section :

A

fixation - dehydration - clearing - embedding - sectioning - staining - mounting

40
Q

Describe the fixation stage

A

specimen soaked in a fixative (chemical) which preserves and stops the material from changing

41
Q

Describe the dehydration stage

A

remove water with dehydrating agent (ethanol)

42
Q

Describe the clearing stage

A

drive out the alcohol by putting into a clearing agent

43
Q

Describe the embedding stage

A

heat wax, put in specimen and leave to cool

this will support it and allow you to carve off a section

44
Q

Describe the sectioning stage

A

cut off a section of the specimen, which will be measured in micro meters

45
Q

Describe the staining stage

A

use appropriate staining chemical (dye for LM / melted lead for EM) which will attach to organelle’s chemical (e.g. if looking at cell wall, attaches to cellulose)

46
Q

Describe the mounting stage

A

put on slide, put on appropriate liquid, put on cover slip

47
Q

describe structure of mitochondrion

A
  • 2 membranes
  • inner membrane is folded to form cristae (crista)
  • inside is matrix (has enzymes for respiration)
48
Q

describe structure of chloroplast

A
  • contains granum / stroma / lamella
  • photosynthesis occurs in stroma / grana
  • 2 membranes + thylakoid membrane inside
49
Q

what is centriole made up from ?

A

micro tubules

50
Q

describe structure of cilia

A

ring of 9 pairs of protein micro tubules, with 2 in the middle (known as 9 + 2 formation)

51
Q

describe strucutre of flagellum

A

9 + 2 formation

52
Q

what does Golgi body make ?

A

lysosomes

A level Biology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions