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Cell Biology Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

2 types of eukaryotic cells

A

animal + plant

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2
Q

what do animal + plant cells both have in common

A

both have a nucleus

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3
Q

what does nucleus contain

A

DNA of the cell

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4
Q

3 key features of eukaryotic cells

A

eukaryotic cells have a cell membrane, cytoplasm and genetic material enclosed in a nucleus.

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5
Q

what are bacteria

A

prokaryotes

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6
Q

key difference of prokaryotic cells

A

genetic material not inclosed in a nucleus

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7
Q

what cells are smaller
prokaryotes/ eukaryotes

A

prokaryotes much smaller

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8
Q

6 features in a prokaryote

A

cell membrane
cell wall
cytoplasm
plasmids
loop of dna
flagellum

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9
Q

4 characteristics of prokaryote

A

single celled
x nucleus- loop of dna
plasmids- small dna rings
smaller then eukaryots

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10
Q

measurement names in descending order

A

metre
centimetre
millimetre
micrometre
nanometre

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11
Q

symbols for measurements in descending order

A

m
cm
mm
μm
nm

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12
Q

multiplication factor of measurements
(what would you times it by to get number in metre)

A

metre 1
centimetre 10^-2
millimetre 10 ^-3
micrometre 10 ^-6
nanometre 10^-9

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13
Q

example of something that’s 1mm

A

tip of ball point pen

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14
Q

size of typical human cell

A

10-20 μm

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15
Q

size of one heamaglobin molecule

A

5nm

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16
Q

what does 1 order of magnitude mean

A

10 times

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17
Q

a pineapple is 10 times larger than a lemon.
describe using order of magnitude

A

pineapple 1 order of magnitude larger than lemon

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18
Q

a dog is 100 times longer than a wood louse.
describe using order of magnitude

A

dog is 2 orders of magnitude longer than wood louse

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19
Q

every order of magnitude is … … greater than the one before

A

every order of magnitude is 10 x greater than the one before

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20
Q

how many orders of magnitude is 1000x

A

3 orders of magnitude
(count 0’s)

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21
Q

name 5 subcellular structures in animal cell

A

nucleus
cytoplasm
cell membrane
mitrochondria
ribosomes

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22
Q

how do you know that animal cells are eukaryotic

A

genetic material enclosed in nucleus

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23
Q

what is the cytoplasm + function

A

watery solution where chemical reactions take place

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24
Q

example of chemical reaction that can take place in cytoplasm

A

first stage of respiration

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25
Q

function of cell membrane

A

controls which molecules enter + leave cell

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26
Q

why can’t we see mitochondria and ribosomes on some pictures

A

they are too small

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27
Q

function of mitrochondria

A

site of aerobic respiration
provide energy for the cell

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28
Q

ribosomes are very small. Can they be seen with an electron microscope, a light microscope, or both

A

electron microscope

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29
Q

function of ribosomes

A

site of protein synthesis

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30
Q

example of what protiens are used for

A

enzymes

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31
Q

whats smaller, mitochondria or ribosomes

A

ribosomes

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32
Q

differences between plant and animal cell

A

plants have a regular shape
(animal cells can change their shape easily)
plant cells packed with chloroplasts

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33
Q

what does the nucleus contain

A

genetic material

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34
Q

what structures do plant and animal cells share

A

nucleus
cytoplasm
cell membrane
mitochondria
ribosomes

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35
Q

what additional structures do plant cells have
-function

A

chloroplasts- site of photosynthesis
cell wall- strengthens cell
permanent vacuole- gives plant cell shape

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36
Q

what do chloroplasts contain

A

chlorophyll

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37
Q

what is the cell wall made of

A

cellulose

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38
Q

what is the vacuole filled with

A

cell sap

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39
Q

most / some / few animal cells are specialised
choose an option

A

most

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40
Q

what does it mean if an animal cell is specialised

A

has adaptations to help carry out a particular function

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41
Q

what do scientists call it when cells become specialised

A

differentiation

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42
Q

job of sperm cell

A

join with an ovum

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43
Q

a sperm cell is present in the process of what

A

fertilisation

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44
Q

what is an ovum

A

egg cell

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45
Q

what happens during fertilisation

A

the genetic info of the ovum and the sperm cell combine

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46
Q

4 adaptations of sperm cells

A

-only contain half the genetic info of a normal adult cell
-long tail that is streamlined
-packed full of mitochondria
-contain enzymes

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47
Q

why do sperm cell have a long tail that is streamlined

A

streamlined makes swimming easier
tail to swim

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48
Q

why are sperm cell packed full of mitrochondria

A

to get energy for swimming

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49
Q

why do sperm cells contain enzymes

A

so they can digest through outer layer of ovum

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50
Q

job of nerve cell

A

send electrical impulses around body

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51
Q

adaptations of nerve cell

A

long axon
myelin sheath insulates axon
synapses at end of axon
cell body has dendrites

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52
Q

what does axon do

A

carries electrical impulses from one part of the body to another

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53
Q

what does the myelin insulating the axon do

A

speeds up transmission of nerve impulses

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54
Q

what are synapses

A

junctions that allow impulses to pass from one nerve cell to another

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55
Q

what do dendrites do

A

increase surface area so other nerve cells connect more easily

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56
Q

key feature of muscle cells

A

they contract

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57
Q

adaptations of muscles cells

A

contain protien fibres
packed with mitrochondria

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58
Q

how do protien fibres work in a muscle cell

A

when a muscle cell contracts, protien fibres shorten, decreasing length of the cell

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59
Q

why are protien fibres useful for muscle cell

A

they can change their length

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60
Q

why are muscle cell packed full of mitrochondria

A

provide energy for muscle contraction

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61
Q

what do muscle cells work together to form

A

muscle tissue

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62
Q

what are the 3 specialised animals cell u need to know

A

sperm cells
nerve cell
muscle cells

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63
Q

3 specialised plant cells u need to know

A

root hair
xylem
phloem

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64
Q

adaptations of root hair cell

A

root hairs
dont contain chloroplasts

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65
Q

why are the hairs helpful to the root hair cell
3 points

A

increase s.a
so root can absorb water and dissolved minerals easily

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66
Q

why do root hair cells not contain chloroplasts

A

because they are underground

(chloroplasts contain chlorophyll- they are the site of photosynthesis
photosynthesis requires light energy
the root cant get light energy
so no need for chloroplasts)

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67
Q

where are xylem cells found

A

in plant stem

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68
Q

what do xylem cell form

A

long tubes

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69
Q

what do xylem tubes carry-
from where to where

A

xylem carries water and dissolved minerals from roots to leaves

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70
Q
A

very thick walls -containing lignin
end walls between cells are broken down
no nucleus, ribosome, chloroplasts
(no internal structures)

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71
Q

thick cell walls in the xylem are sealed with lignin
positive and negative of this

A

provide support to plant
xylem cells die

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72
Q

why is it useful that in xylem cells, the end walls between cells are broken down

A

the cells can form a long tube- water and dissolved minerals can flow easily

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73
Q

xylem cells have no internal structures. why is this good

A

easier for water and minerals to flow

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74
Q

job of phloem tubes

A

carry dissolved sugars up and down plant

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75
Q

what two cells do phloem cells consist of

A

phloem vessel cell
companion cell

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76
Q

adaptations of phloem vessel cell

A

no nucleus-limited cytoplasm
end walls have pores-sieve plates

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77
Q

phloem vessel cells have:
no nucleus-limited cytoplasm
end walls have pores-sieve plates
why ?

A

allow dissolved sugar to move through interior of phloem vessel cell

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78
Q

adaptation of companion cell

A

companion cell has mitrochondria

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79
Q

why is it useful that the companion cell has mitochondria

A

mitochondria in companion cell provide energy to the phloem vessel cell.

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80
Q

why do phloem vessel cells not have many mitrochondria

A

because they have a limited cytoplasm

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81
Q

how is the companion cell and phloem vessel cell connected

A

by pores

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82
Q
A

stage
lamp
objective lenses
eyepiece
coarse focusing lens
fine focusing lens

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83
Q

what do we put on the stage of the microscope

A

the microscope slide

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84
Q

what does the stage have to keep the slide in place

A

clips

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85
Q

what is below the stage

A

the lamp

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86
Q

what happens to the light from the lamp

A

it passes through the microscope slide

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87
Q

what do some optical microscopes have instead of a lamp

A

a mirror

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88
Q

what does the mirror in an optical microscope do

A

reflect light up through the microscope slide

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89
Q

what is found above the stage

A

the objective lenses

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90
Q

how many objective lenses do most microscopes have
give examples of the magnification these can have

A

3
4x 10x 40x

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91
Q

what is found at the top of the microscope

A

eyepiece

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92
Q

what does the eyepiece contain

A

the eyepiece lens

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93
Q

what magnification does the eyepiece lens have

A

10x

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94
Q

name the two dials found on an optical microscope

A

coarse focusing dial
fine focusing dial

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95
Q

RP 1-use a light microscope to observe, draw and label a selection of plant and animal cells

A

place slide onto stage
use clips to hold slide in place
select lowest power objective lens
-position objective lens so it almost touches the slide
- to do this, slowly turn coarse focusing dial
-look at microscope from side while adjusting objective lens
-look down eyepiece and slowly turn CFD till cells come into focus
-use FFD to bring cells into clear focus
-use pencil to make clear, labelled drawing of some of the cells
- write down the magnification

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96
Q

what will happen if we look through the eyepiece while adjusting the objective lens

A

could damage the slide

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97
Q

what does turning the CFD cause

A

increases distance between objective lens and slide

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98
Q

how to calculate total magnification

A

mg of eyepiece x mg of objective lens

99
Q

once we’ve worked out total magnification we can select a higher power objective lens eg 10x. what must we do when selecting a higher power objective lens

A

adjust fine focusing dial to bring cells back into focus

100
Q

when using an optical microscope on an animal cell, what structures can be seen

A

cytoplasm
nucleus
cell membrane
mitrochondria

101
Q

when using an optical microscope on an animal cell, what structures can be seen

A

cytoplasm
nucleus
cell wall
vacuole
chloroplasts

102
Q

what should you include on your drawing
how would you do this

A

magnification scale
put clear ruler over stage
measure diameter of field of view in mm
show this on drawing using a scale bar
write magnification eg 100x

103
Q

early microscopes and modern microscopes both use what to view a specemin

A

light

104
Q

downsides of light microscope- technical aspects

A

limited magnification
limited resolution

105
Q

what does limited resolution mean

A

even if we increase magnification, the image will be blurred

106
Q

what does limited magnification mean

A

magnification isnt powerful enough

107
Q

why was electron microscope created

A

to study cells in finer detail

108
Q

key advantage of electron microscope

A

much higher resolution and magnification than light microscope

109
Q

example of what an electron microscope can do, a light microscope cant

A

see detail in the nucleus

110
Q

magnification= image size/actual size
what is the size measured in

A

mm

111
Q

are bacteria prokaryotes or eukaryotes

A

pro

112
Q

bacteria multiply by………..

A

simple cell division

113
Q

another word for simple cell division is

A

binary fission

114
Q

describe binary fission

A

one bacterial cell splits into two bacterial cells

115
Q

how often can bacteria carry out binary fission
what does this depend on

A

once every 20 mins
enough nutrients
suitable temp

116
Q

number of bacteria =

A

2^n
n is number of rounds of division

117
Q

a type of bacterium divides every 20 minutes. calculate no. of bacteria present after 3 hours in standard form

A

3 hours = 180 mins
180 / 20 = 9 rounds of division
2^9 = 512
5.12 times 10^2

118
Q

how to prepare an uncontaminated bacteria culture using aseptic techniques
4 things u must do

A

–Petri dishes and culture media sterilised before use
–inoculating loops sterilised by passing through a flame
– lid of the Petri dish secured with adhesive tape + stored upside down in incubator
– incubated at 25* in school laboratories

119
Q

what is an agar gel plate

A

nutrient broth set into a gel
in a petri dish

120
Q

what do bacteria do on an agar gel plate

A

grow into visible colonies

121
Q

Petri dishes and culture media must be sterilised before use. why

A

to kill unwanted microorganisms
prevent contamination

122
Q

an innoculating loop is used to…..

A

transfer bacteria into the culture

123
Q

why is the lid of petri dish attached with tape

A

to stop lid from falling off
and unwanted microorganisms entering

124
Q

why is the agar plate stored upside down in the incubator

A

stop moisture dripping down onto bacteria and disrupting colonies

125
Q

in school laboratories, cultures should generally be incubated at
25°C. why

A

reduces chances that harmful bacteria will grow

126
Q

RP 2: investigate the effect of antiseptics or antibiotics on bacterial growth
using agar plates and measuring zones of inhibition.

describe the 7 steps

A

-clean bench with disinfectant solution
- sterilise innoculating loop by passing through bunsen flame
-open sterile agar gel plate near bunsen burner flame
-spread chosen bacteria evenly over plate using loop
- place sterile filter paper disk containing antibiotic onto plate
- incubate plate at 25*
-after few days measure zone of inhibition using πr².

127
Q

why do we clean the bench with disinfectant solution

A

kill microorganisms that could contaminate our culture

128
Q

why do we open the agar gel plate near the bunsen burner flame

A

flame kills bacteria in the air

129
Q

In RP2 (investigating effect of antibiotics on bacteria growth using agar gel plates) what did the bacteria do

A

formed a layer on the agar gel

130
Q

what is the zone of inhibition and the equation

A

region where bacteria havent grown
πr².

131
Q

calculation zone of inhibition helps us measure ……

A

the effect of the antibiotic

132
Q

what is found in the nucleus

A

chromosomes made of dna molecules

133
Q

how many of each chromosome is found in body cells.
are they single or paired

A

2 of each chromosome
paired

134
Q

how many chromosomes do human body cells contain

A

23 pairs of chromosomes in human body cells

135
Q

which human cells contain unpaired chromosomes

A

gametes

136
Q

ow many chromosomes do gametes have

A

23 UN paired chromosomes

137
Q

what do chromosomes carry a large number of?
(not dna)

A

genes

138
Q

what do genes do

A

determine many of our features

139
Q

how many genes do most human chromosomes contain ( approx)

A

hundreds

140
Q

what is the cell cycle

A

the series of stages for cells to divide

141
Q

2 ways cells can divide by

A

mitosis
meiosis

142
Q

brief 3 main stages of the cell cycle,
1 to 2 words to describe each stage

A

-growth and replication
-mitosis.
-division

143
Q

1st stage of cell cycle
4 points

A

cell grows
number of sub cellular structures increases
DNA replicates
2 copies of each chromosome formed

144
Q

2nd stage of cell cycle
4 points

A

mitosis-
1 set of chromosomes pulled
to each end of cell
nucleus divides

145
Q

3rd stage of cell cycle
3 points

A

cell membrane and cytoplasm divide to form 2 identical cells

146
Q

how many cells and how many chromosome pairs are there at the start and at the end of the cell cycle

A

1 cell- 2 pairs of chromosomes
2 identical cells- 2 pairs of chromosomes

147
Q

really simply, what does mitosis do

A

copies one cell intotwo

148
Q

functions of mitosis
x3

A

growth and development of multicellular organisms

for an organism to repair itself

asexual reproduction

149
Q

what does multicellular organism mean and example

A

organism with more than one cell
plants/animals

150
Q

what happens to the ovum after its fertilised
4 points

A

-ovum undergoes mitosis
-forms an embryo
-the cells in the embryo undergo mitosis
-cells in embryo change into specialised cells

151
Q

what is an embryo

A

ball of cells

152
Q

define differentiation

A

the process of specialisation

153
Q

what is special about the cells in an early embryo
3 points

A

they have not differentiated
they can differentiate into any type of body cell

154
Q

what are embryonic stem cells

A

the undifferentiated cells in an early embryo

155
Q

define stem cell

A

an undifferentiated cell
that can give rise to more cells
of the same type
and can differentiate
to form other types of cells

156
Q

where can stem cells be found in adults

A

bone marrow

157
Q

what can adult bone marrow stem cells differentiate into

A

blood cells
eg
wbc
rbc
platelets

158
Q

unlike ….. stem cells …… stem cells can ….. differentiate into …. other type of cell

A

unlike embryonic stem cells, adult stem cells can not differentiate into any other type of cell

159
Q

stem cells use in medicine

A

bone marrow transplant
therapeutic cloning

160
Q

what is leukemia

A

cancer of the bone marrow

161
Q

process for a patient with leukemia get a bone marrow transplant
5 points

A

-patients existing bone marrow destroyed using radiation
-recieve transplant of bone marrow from donor
-stem cells in bone marrow divide
-new bone marrow is formed
- stem cells in bone marrow also differentiate and form blood cells

162
Q

2 problems with bone marrow transplants / stem cell transplants

A

donor must be compatible with patient
viruses can pass from donor to patient

163
Q

why must the bone marrow donor be compatible with the patient

A

if not, white blood cells produced by the donated bone marrow could attack the patients body

164
Q

What happens in therapeutic cloning - in the patients body and before
3 sentences

A
  • an embryo is produced with same genes as the patient
    -stem cells from the embryo transplanted into patient w/out being rejected by immune system
    -stem cells differentiate inside patient to replace cells which don’t work correctly
165
Q

what medical conditions can therapeutic cloning used to help

A

diabetes
paralysis

166
Q

risks of therapeutic cloning

A

ethical/religious objections
transfer viral infection

167
Q

what is special about meristem tissue

A

the tissue can differentiate into any type of plant cell
throughout entire life of plant.

168
Q

where is meristem tissue found in plants

A

roots
buds

169
Q

what can stem cells from meristems be used to produce

A

produce clones of a plant quickly + cheaply

170
Q

what are the type of plant clones that can be produced from meristem tissue
why clone these plant type

A

rare species - to protect from extinction
crop plants with special features- large numbers for farmers

171
Q

eg of a special feature crop plants may have

A

disease resistance

172
Q

what are all cells surrounded by

A

a cell membrane

173
Q

define diffusion

A

spreading out of particles of any substance resulting in the net movement of particles from an area of high concentration to lower concentration

174
Q

the 3 substances that diffuse in and out of cell that u need to know

A

oxygen
carbon dioxide
urea

175
Q

what do cells need oxygen for

A

respiration

176
Q

what carries out respiration

A

mitrochondria

177
Q

why are cells in blood surrounded by a high amount of o2

A

because oxygen is transported into bloodstream from the lungs

178
Q

why does diffusion happen in cells in the blood

A

for mitochondria in a cell to carry out respiration, oxygen is needed.
there’s a higher amount of oxygen in the blood than in the cell

179
Q

what is the oxygen brought into the cell for respiration, used to produce

A

energy
carbon dioxide

180
Q

name a product that diffuses only out of cells in the body

A

urea ( a waste product)

181
Q

where is the urea that diffuses out of cells created

A

in cells

182
Q

when urea diffuses out of cells it diffuses into…..

A

blood plasma

183
Q

once urea diffuses into the blood plasma, what is it excreted by

A

kidneys

184
Q

2 substances that are transported in and out of cells in the body

A

carbon dioxide
oxygen

185
Q

Factors which affect the rate of diffusion are:

A

difference in concentration
temp
s.a of the membrane

186
Q

scientists call the difference in concentration ……..

A

concentration gradient

187
Q

describe relationship between concentration gradient and diffusion

A

the greater the concentration gradient, the faster diffusion takes place

188
Q

describe relationship between temperature and diffusion

A

the higher the temp. the greater the rate of diffusion

189
Q

explain why the higher the temp. the greater the rate of diffusion

A

particles have mote kinetic energy
they move faster

190
Q

describe relationship between s.a of cell membrane and rate of diffusion

A

the larger the s.a of cell membrane, the greater the rate of diffusion

191
Q

describe simply the s.a to vol ratio of single-celled organisms

A

single- celled organisms have large s.a to vol ratios
(large surface areas compared to their volume)

192
Q

what do single celled organisms rely on for transport of molecules in and out of cells

A

diffusion

193
Q

give an example of a gas diffusing into a single-celled organism and include where the gas would diffuse through

A

oxygen diffuses in through membrane

194
Q

work out s.a to vol ratio of a 1mmx1mm Cube

A

s.a = (1x1) x6 =6 mm^2
vol=1x1x1 =1 mm^3
s.a to vol = 6:1

195
Q

describe relationship between increase in size of organism and s.a : vol ratio

A

as organisms get larger, s.a : vol ratio falls SHARPLY

196
Q

As organisms get larger, s.a : vol ratio falls SHARPLY
what types of organisms is this a problem for?
describe how this is a problem for those organisms using the example of oxygen?

A

multicellular organisms

cells on surface can get enough oxygen by diffusion
cells in centre of organisms don’t get enough gas
they are too far away from surface

197
Q

2 ways animals solved issue of diffusion not able to supply oxygen to cells in centre of organism

A

-special structures for gas exchange with high s.a

-transport system to carry gases around body

198
Q

eg of special structure for gas exchange with high s.a in mammals

A

lungs

199
Q

where do fish get their oxygen from

A

water

200
Q

describe how fish get their oxygen

A

water passes into mouth
flows over gills
where the oxygens transported into bloodstream

201
Q

what do gills contain that allow gas to pass in and out of blood

A

Many fine filaments

202
Q
A

deoxygenated blood passes into filament
oxygen diffuses from water into blood
oxygenated blood returns to body

203
Q

3 adaptations of filaments

A

give gills massive s.a
thin membrane
efficient blood supply

204
Q

why do filaments in fish gills have a thin membrane

A

for a short diffusion pathway

205
Q

2 things the efficient blood supply in filaments of fish gills do

A

takes the oxygenated blood away
ensures a high concentration gradient

206
Q

filaments give gills massive s.a,
have thin membrane &
have an efficient blood supply.
what do these adaptations do

A

make diffusion as efficient as possible

207
Q

the effectiveness of an exchange surface is increased by 4 things. what are they

A

large s.a
thin membrane
efficient blood supply
being ventilated (gas exchange)

208
Q

define osmosis

A

the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

209
Q

describe a dilute and concentrated solution

A

dilute solution contains high water concentration

concentrated solution contains low water concentration

210
Q

what do partially permeable membranes do

A

allow some, not all, molecules to pass through

211
Q

describe the cytoplasm

A

a concentrated solution

212
Q

what will happen to an cell when placed in water

A

osmosis will take place
(from outside to inside cell)
cell will expand
may burst

213
Q

what will happen if animal cell placed in an extremely concentrated solution

A

water will move out of cell by osmosis
cell will shrink

214
Q

what will happen if plant cell placed in water

A

water move into cell by osmosis
cell will expand
cell will become turgid

215
Q

what does turgid mean

A

cell becomes swollen

216
Q

what structure prevents plant cell from bursting when cell put in water

A

cell wall

217
Q

what will happen if plant cell put in concentrated solution

A

water moves out of cell by osmosis
cell becomes flaccid

218
Q

what does it mean if a cell becomes flaccid

A

the cell shrinks

219
Q

RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue
how would you carry out the practical

A

-peel potato skin
-use cork borer- make 3 potato cylinders
-trim cylinders to same length with scalpel - 3cm
-measure length and mass of each cylinder
-use ruler and balance
- put each into a test tube
- add 10cm^3 of different molar sugar solution to #1 and #2 tube
-add 10cm^3 distilled water to #3 tube
-leave cylinders overnight in rack so osmosis happens
- remove cylinders and roll on paper towel
- remeasure length and mass of cylinders
- calculate % change in length and mass

220
Q

why do we use a cork borer when cutting potatoe

A

make all cylinders same diameter

221
Q

why should we not cut potato pieces to less then 3cm long

A

wont be able to measure effect of osmosis

222
Q

why use distilled water instead of tap water in RP3 with potatoes

A

distilled contains no dissolved substances
they could affect rate of osmosis

223
Q

in RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue
why do we roll potato cylinders on paper towel after leaving them in a solution over night

A

to remove surface moisture

224
Q

potato has starting mass of 1.56g
this increases by 0.25g
how do u work out % increase

A

(0.25/1.56 ) x100

225
Q

potato cylinder has starting mass of 1.32g
this decreases by 0.19 g
how do u calculate percentage decrease

A

(-0.19/1.32) x100
= -14.39% (to 2 dp)

226
Q

in RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue
what would the axis be on the graph you make

A

y= % change in mass
x= concentration of sugar/salt solution

227
Q

in RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue

describe the trend and reasons for the trend on your graph

A

negative gradient
( straight line )
goes from positive change in mass to negative

in water, potato gains mass through osmosis

in the concentrated solution, potato loses mass by osmosis out of cell

(in higher concentrated solution, potato loses even more mass by osmosis out of cells)

228
Q

in RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue

what does it mean when the line on your graph for change in mass against concentration crosses the x axis

A

no change in mass

concentration of sugar out of cell is same as concentration in cell
no osmosis happens

that value is the approx sugar concentration in the cell

229
Q

what two graphs can be plotted from RP3: investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue

A

change in mass against concentration of solution

change in length against concentration of solution

230
Q

give two examples of the different molar sugar solutions that can be used in RP3

A

0.5 molar
0.25 molar

231
Q

define active transport

A

movement of particles from an area of low concentration to an area of high concentration (dilute-concentrated solution) against the concentration gradient.

232
Q

what does active transport require

A

energy from respiration

233
Q

state the 2 differences between active transport and diffusion

A

AT:
movement against concentration gradient
requires energy

234
Q

2 examples of active transport
include the molecule and where the molecule is travelling to and from

A

sugar absorbed from low concentrations in the lumen to cells by active transport then from cells to blood

mineral ions absorbed into root hairs from dilute solutions in soil

235
Q

what is the lumen
what happens in the lumen

A

the cavity of the small intestine
where food is digested

236
Q

what is found in the lumen
give an example

A

the molecules produced from digestion of food
(eg glucose)

237
Q

what do mitochondria do
x2

A

carry out respiration
provide energy for active transport

238
Q

why do plants need mineral ions

A

for healthy growth

239
Q

what do root hair cells do

A

transport ions into plant from soil

240
Q

give an example of a mineral ion a plant needs and what its used for

A

magnesium
to make chlorophyll in the leaves

241
Q

what happens to mineral ions once they are absorbed by active transport from soil to root hair cells

A

ions transported to xylem vessel
and moved to the leaf

242
Q

root hair cells contain many ……… to provide ……. for active ……..

A

root hair cells contain many mitochondria to provide energy for active transport

243
Q

what are sugar molecules in our bodies cells used for

A

cellular respiration

BIology (11 decks)

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