cell structure & function Flashcards
(119 cards)
1
Q
the cell is the……
A
the cell is the structural & functional unit of living things
2
Q
most cells can only be seen under a…….
A
microscope
3
Q
draw a lable diagram of the light microscope
A
notes
4
Q
another word for the iris diaphragm is…..
A
condenser
5
Q
the condenser controls…….
A
controls the amount of light
6
Q
how does the light microscope work?
A
it uses a beam of light to view the specimen and glass lenses for magnification
7
Q
the light microscope uses ….. passing through …… to ……. … ……
A
the light microscope uses light passing through lenses to magnify the image
8
Q
how do i calculate the total magnification of the image
A
the power of the eyepiece lense x the power of the objective lense
9
Q
the best microscopes can magnify images up to…….
A
1000x
10
Q
give an example of an animal cell
A
a cheek cell
11
Q
draw a diagram of a cheek cell under a light microscope
A
notes
12
Q
what is another word for cell membrane?
A
plasma membrane
13
Q
the nucleus contains…..
A
DNA
14
Q
cytoplasm consists of ………….
A
water and dissolved chemicals
15
Q
cytoplasm is the……..
A
watery fluid around the nucleus
16
Q
an animal call CAN have…..
A
temporary small vacuoles
17
Q
give an example of a plant cell
A
an onion cell
18
Q
draw a diagram of a plant cell under a light microscope
A
notes
19
Q
give 3 differences between plant cells & animal cells
A
plant cell animal cell
cell wall no cell wall
large permanent vacuole temporary small vacuoles
chloroplasts no chloroplasts
20
Q
how does the electron microscope work?
A
uses a beam of electrons (instead of light) to view the specimen and magnets for magnification
21
Q
electrons are focused using ……. onto very …. specimens
A
electrons are focused using magnets onto very thin specimens
22
Q
using an electron microscope specimens can be magnified bigger than
A
500,000 times
23
Q
electron microscopes can only be used on…..
A
dead specimens only
24
Q
using an electron microscope the structure of cells is called …. (2)
A
the ultrastructure or the fine structure
25
what is the ultrastructure of a cell?
the fine detailed structure of cells using an electron microscope
26
draw a diagram of the ultrastructure of an animal cell
notes
27
chromatin are...
threads
28
chromatin become ....... when the cell divides
chromosomes
29
what is the plural of a mitochonrion
mitochondria
30
draw a diagram of the fine structure of a plant cell
notes
31
the cell membrane is thick or thin?
thin
32
the cell membrane is actually a ....... membrane
double membrane
33
all biological membranes have a ...... structure to the cell membrane ie the ..... membrane and ......... membrane
all biological membranes have a similar structure to the cell membrane ie the nuclear membrane and mitochondrial membrane
34
draw a cell membrane under a light microscope vs under an electron microscope
notes
35
a cell membrane is made up of....
phospholipids and protein
36
phospholipids are arranged in a ...... layer called the ......... .......
phospholipids are arranged in a double layer called the phospholipid bilayer
37
the proteins are ....... or partly .......... in the bilayer and can .....
the proteins are completely or partly embedded in the bilayer and can move
38
the model of the membrane structure is....
| why?
fluid-mosaic model
| because the proteins are continually changing positions
39
phospholipids have a water-loving ....... group and a water-hating ...... group and therefore ......
phospholipids have a water-loving phosphate group and a water-hating lipid group and therefore the phosphates are on the outer surfaces and the and the lipids are in the middle of the membrane
40
give the 4 functions of the membrane
- gives the cell its shape and provides support for the cell
- encloses the cell contents
- semi-permeable barrier
- a site for metabolic reactions for eg. the proteins in the membrane act as enzymes
41
what is another way of saying semi-permeable?
selectively-permeable
42
what is a semi-permeable membrane?
a membrane that allows some things to pass through but not others
43
what is an enzyme?
a biological catalyst that controls chemical reactions in the cell
44
the cytoplasm is a ....
watery gel with organelles suspended in it
45
what does the word organelles mean?
small organs
46
give the 3 organelles present in plant and animal cells
- nucleus
- ribosomes
- mitochondria
47
give the 2 organelles which are found in plant cells only (may be exceptions)
- large vacuoles
| - chloroplasts
48
cytoplasm + organelles =
protoplasm
49
protoplasm
cytoplasm + organelles =
50
give the 3 functions of the cytoplasm
- supports the organelles
- stores materials eg. food
- site for chemical reactions for eg. stage 1 of respiration occurs in the cytosol
51
what is the cytosol?
the cytoplasm around the mitochondria
52
the nucleus is the ....... organelle and is surrounded by a ..... ..... ........
the nucleus is the largest organelle and is surrounded by a double nuclear membrane
53
the nuclear membrane has ..... .....
the nuclear membrane has nuclear pores
54
what do the nuclear pores do
allow substances in/out of the membrane
55
the nucleus contains ........ which is a ......-like material
the nucleus contains chromatin which is a thread-like material
56
what is chromatin made up of?
DNA & protein
57
what does DNA stand for?
deoxyribonucleic acid
58
during cell division the chromatin ........ (........ & ........) to become ......... which is a .....-like ......
during cell division the chromatin condenses (shortens & thickens) to become chromosomes which is a thread-like structure
59
every ........ has a ....... number of .........
every organism has a definite number of chromosomes
60
every human has .. chromosomes in every ...... and because chromosomes .... .. .... that equals..pairs
every human has 46 chromosomes in every nucleus and because chromosomes occur in pairs that equals 23 pairs
61
chromosomes contain .....
chromosomes contain genes
62
what do genes do?
genes control characteristics (for example eye colour) by instructing the cell to make more proteins.
63
give the 2 functions of the nuclear membrane
- enclose the nuclear contents
| - allow materials in and out of the nucleus through pores
64
the nuclear membrane allows materials in and out of the nucleus through pores.
give an example of a material that might go in and out through the nuclear membrane
RNA
65
give the 3 functions of the nucleus
- controls activity in the cell
- contains DNA
- controls the replication of DNA and nuclear division
66
what is the replication of DNA?
when DNA makes an exact copy of itself
67
what is the smallest organelle?
the ribosomes
68
do ribosomes have membranes?
nope
69
what are ribosomes made of?
protein and RNA
70
what does RNA stand for?
ribonucleic acid
71
where are ribosomes found (2)?
- free in the cytoplasm
| - attached to membranes
72
what is the function of ribosomes?
proteinsynthesis
73
what shape is a mitochondrion?
rod shaped
74
mitochondria have a ...... membrane (similar to the ...... membrane). They have an outer membrane which is ...... and an inner membrane which is ......
mitochondria contain their own ...
mitochondria have a double membrane (similar to the plasma membrane). They have an outer membrane which is smooth and an inner membrane which is folded.
mitochondria contain their own DNA
75
what is the function of a mitochondrion?
the mitochondrion is a site for respiration in the cell
76
the cell wall is made of ......... which is the ..... in our diets.
the cell wall is made of cellulose which is the fibre in our diets.
77
the .... .... is fully permeable but the ........ is only semi-permeable
the cell wall is fully permeable but the membrane is only semi-permeable
78
the cell wall is ..... but ........
the cell wall is tough but flexible
79
the middle lamella is .........
the region between adjacent plant cells
80
the region between adjacent plant cells is called the ........
middle lamella
81
the middle lamella contains ....... ....... which ...... the cells together
the middle lamella contains calcium pectate which cements the cells together
82
give the 3 functions of the cell wall
- gives mechanical strength & support to the cell and collectively the whole plant
- gives the cell its shape
- prevents the cell from bursting due to the uptake of water
83
what is an organelle (small organ)?
a small structure found inside cells
84
what is stroma
the fluid inside chloroplasts
85
in the chloroplast name the place where the light and dark stage of photosynthesis occur
light stage -granuum
| dark stage - stroma
86
cellulose is a .... made of l.... chains of .......
cellulose is a carb made of long chains of glucose
87
give 3 things the vacuoles store
water
food
waste
88
draw a diagram of a chloroplast
notes
89
what is the plural of granuum
grana
90
the double membrane of the chloroplast is similar to the ....
plasma membrane
91
the ... like stroma in the chloroplast runs a ....................
the gel like stroma in the chloroplast runs a system of membranes
92
membranes stacked in places to form ...
grana
93
grana contain a ..... pigmant which means .............
grana contain a green pigmant which means chlorophyll is present on the grana
94
name two things that may also be present in the stroma
starch grains
| ribosomes
95
does the chloroplast contain its own DNA?
yes
96
what is the function of the chloroplast?
photosynthesis
97
glucose is made up of ....
oxygen and starch
98
what colour is a leucoplast
pale
99
define a leucoplast
| give example
a colourless organelle like a chloroplast that store food
| eg. store starch in potatoes
100
define a vacuole
a large sac filled with fluid (cell sap) surrounded by a single membrane
101
give 3 functions of vacuoles
- takes in water by osmosis
- a turgid cell has a vacuole that is full of water. Turgid cells are important for the support of the plant
- stores substances like water, dissolved food and dissolved food.
102
a turgid cell is .... and ....
swollen and hard
103
define osmosis (short quick anwser)
the diffusion of water through a semi permeable membrane
104
give 4 differences or similarities of prokaryotik vs eukaryotic cells
-prokaryotic cells have no nuclear membrane around DNA (ie. no true nucleus).
eukaryotkic cells have a nucleur membrane
-prokaryotic cells have no membrane bound organelles ie. mitochondria or chloroplasts
eukaryotic cells have membrane bound organelles
-prokaryotic cells have ribosomes
eukaryotic cells have ribosomes
-prokaryotic cells are smaller than eukaryotic cells
eukaryotic cells are bigger than prokaryotic cells
105
give an example of a prokaryotic cell
bacteria
106
give 4 examples of eukaryotic cells
- fungi
- protists
- plants
- animal cells eg cheek cells
107
- name an animal tissue that may contain a large number of mitochondria
- why
- muscle tissue
| - becAUSE it requires a lot of energy
108
mitochondria can self-replicate independently of the nucleus. What biomolecule does it contain that enables it to do this?
DNA
109
namea kingdom whos members do not have a nucleus in their cells
monera
110
Define a tissue
A group of cells working together for the same function
111
Give 3 reasons why organisms need H2O
- as a solvent
- transport
- turgidity in cells
112
What term is used to describe organisms whose cells contain a nucleus?
Eukaryotes
113
Suggest a reason why the organelle involved in aerobic respiration is found in different amounts in different cells.
Cells need different amounts of energy
114
What term is used to describe organisms whose cells do not have a nuclei?
Prokaryotes
115
Name an organelle other than the nucleus that contains genetic material
Chloroplasts / mitochondria
116
State 3requirements for successful tissue culture
- sterile conditions
- hormones or growth regulators
- nutrients
117
What is the function of te coarse adjustment wheel
Focus with a low power
118
Give 2 reasons why a coverslip is used
- to protect the sample from drying out
| - to protect the lense from the stain
119
Define tissue culture
Cells grown outside an organism on a medium
