Chapter 1 - Cell Biology (not completed) -- done until cell division by mitosis Flashcards
1
Q
define eukaryotic cells
A
they contain their genetic material (DNA) enclosed in a nucleus
2
Q
give 2 example of eukaryotic cells
A
plant cells
animal cells
3
Q
what features do eukaryotic cells have
A
nucleus (containing genetic material)
cell membrane
cytoplasm
4
Q
define prokaryotic cell
A
their genetic material (DNA) is not enclosed in a nucleus
5
Q
give an example of a prokaryotic cell
A
bacteria cell
6
Q
what features do prokaryotic cells have
A
loop of DNA
plasmids (rings of DNA)
cell membrane
cell wall (bacterial)
cytoplasm
they are much smaller than eukaryotic cells
7
Q
define ‘centi’
A
1/100th of a metre
8
Q
what is 1 cm in standard form
A
1 x 10⁻² m
9
Q
define ‘milli’
A
1/1000th of a metre
10
Q
what is 1 mm in standard form
A
1 x 10⁻³ m
11
Q
define ‘micro’
A
1/1,000,000th of a metre
12
Q
what is 1 μm in standard form
A
1 x 10⁻⁶ m
13
Q
define ‘nano’
A
1/1,000,000,000th of a metre
14
Q
what is 1 nm in standard form
A
1 x 10⁻⁹ m
15
Q
what is usually measured in nanometres
A
proteins of cells
16
Q
how big is a typical human cell
A
10-20 μm
17
Q
how big is a haemoglobin molecule
A
5nm
18
Q
how much is one order of magnitude
A
10x
19
Q
how many orders of magnitude is 100x
A
2
20
Q
how many orders of magnitude is 1000x
A
3
21
Q
function of nucleus
A
encloses the genetic material
22
Q
function of cytoplasm
A
watery solution where chemical reactions take place
23
Q
function of cell membrane
A
controls the molecules that can enter and leave the cell
24
Q
function of mitochondria
A
where aerobic respiration takes place
25
function of ribosomes
sites of protein synthesis
26
draw and label an animal cell
27
draw and label a plant cell
28
function of chloroplasts
contain chlorophyll and is the site of photosynthesis
29
function of cell wall
made from cellulose, strengthens the cell
30
function of large permenant vacuole
filled with cell sap, gives the plant its shape
31
what does specialised cells mean?
they have adaptations to help carry out their particular function
when cells become specialised, it is known as differentiation
most animal cells are specialised
32
function of sperm cell
to join with an ovum (egg cell) in a process called fertilisation
33
draw and label a sperm cell
34
function of nucleus in sperm cell
it contains half the genetic material of a normal adult cell
35
function of tail in sperm cell
allows them to swim to the ovum
streamlined to make it easier
36
function of mitochondria in sperm cell
provide energy for swimming
37
function of enzymes in sperm cell
allows them to digest their way through the outer layer of the ovum
38
draw and label a nerve cell
39
function of axon in nerve cell
carries electrical impulses from one part of the body to another
40
function of myelin in nerve cell
insulates axon
speed up transmission of nerve impulses
41
function of synapses in nerve cell
junctions
allow impulses to pass from one nerve cell to another
42
function of dendrites in nerve cell
increases surface are so other nerve cells can connect more easily
43
draw and label a muscle cell
44
adaptations of muscle cells
they can contract (get shorter)
contain protein fibres that can change the length of the muscle cells (when contracting, these shorten, decreases the length of cell)
45
function of mitochondria in muscle cell
provide energy for muscle contraction
46
what happens when muscle cells work together
they form muscle tissue
47
draw and label a root hair cell
48
adaptions of root hair cell
do not contain chloroplasts because they are underground
root hair - increases surface area of root, absorbing more water
49
function of root hair cell
absorbs water and mineral ions from the ground
50
draw and label a xylem cell
51
adaptations of xylem cell
have thick walls with lignin - provides support for plant
dead and hollow - water and mineral ions flow more easily
no internal structure - water and mineral ions flow more easily
52
function of xylem cell
long tubes that carry water and minerals up the plant via the transpiration stream
53
draw and label a phloem cell
54
adaptations of phloem cell
contain phloem vessel cells - no nucleus and limited cytoplasm, for easier transport
sieve plates - allow dissolved sugars to move through cell interior
companion cell - contains mitochondria to provide energy to the phloem vessel cell
55
function of phloem cell
carry dissolved sugars up and down the plant via translocation
56
draw and label and optical microscope
57
steps to using optical microscope
1. place slide on stage, using clips to hold it in place
2. select lowest power of objective lens
3. slowly turn course focusing dial to position objective lens right above the slide
4. look through eyepiece, turn course focusing dial until cells are focused
5. use fine focusing dial to bring cells to clear focus
58
why should we not look through the eye piece when positioning the objective lens
you could accidentally damage the slide.
you should look from the side
59
how to calculate total magnification of microscope
magnification of eyepiece x magnification of objective lens
60
how should we draw a diagram of what we see on the microscope
we should include a magnification scale
we do this by:
* placing clear plastic ruler over stage to measure diameter of field of view in mm
* show this in the drawing using a scale bar
* also include the magnification
61
what do microscope do
they magnify
62
disadvantages of light microscopes
- limited magnification
- limited resolution
63
why might electron microscopes be better than light microscopes
they have greater magnification and resolution
64
equation to calculate magnification
65
how do bacteria multiply
by simple cell division
via binary fission
66
conditions needed for binary fission
carried out once every 20 mins
needs enough nutrients
temperature must be suitable
67
equation for calculating number of bacteria
68
69
aseptic technique for culturing microorgansims
- sterilise all petri dishes/agar plates (kills unwanted microorganisms)
- sterilise inoculating loop with Bunser burner flame
- attach lid of petri dish with adhesive tape (stops lid from falling off and unwanted microorganisms
- place agar plate upside down into an incubator (stops moisture from dripping down onto bacteria)
- incubate at 25°C at schools (reduces chance of harmful bacteria growing)
70
how can you test the effect of antibiotics on bacterial growth
1. clean bench with disinfectant solution (kills microorganisms that could contaminate our culture)
2. sterilise inoculating loop with Bunser burner flame
3. open sterile agar plate near Bunsen burner flame (kills bacteria in the air)
4. use loop to spread chosen bacteria evenly onto the agar plate
5. place sterile filter paper discs containing anitbiotics on agar plate
6. incubate plate at 25°C
7. observe the zone of inhibition
71
what is the zone of inhibition and how can you measure it
region where bacteria hasn't grown
you can measure it by calculating the area of the circle (πr²)
72
where are chromosomes found
in the nucleus, they are made from the molecule DNA
73
how many chromosomes do body cells contain
2 of each chromosome (they are paired)
human body cells contain 23 pairs of chromosomes
74
what do chromosomes carry
large number of genes which determine many of our features
75
what is the cell cycle of mitosis
Stage 1: DNA replicates to form 2 copies of each chromosome. Cell grows and copies its internal structures (e.g mitochondria, ribosomes)
Stage 2: Mitosis takes place. One set of chromosomes is pulled to each end of the cell, nucleus also divides
Stage 3: Cytoplasm + cell membrane divide to form two identical cells
76
