Brainscape's Knowledge GenomeTM

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


See full index

edexcel igcse biology > section a: organisms and life processes > Flashcards

section a: organisms and life processes Flashcards

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

what eight life processes do living organisms have in common

A

movement, respiration, sensitivity/stimuli, growth, reproduction, excretion, nutrition, control,

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

give the organelles found in an unspecialized animal cell

A

cell membrane, cytoplasm, nucleus and mitochondria

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

give the organelles found in an unspecialized plant cell

A

cell membrane, cytoplasm, nucleus, mitochondria, cell wall, vacuole, chloroplasts

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

what do chloroplasts contain

A

chlorophyll

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

what are plant cell walls made of

A

cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do enzymes do in metabolic reactions

A

speed up reactions and control them.

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

what are enzymes known as

A

biological catalysts

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

how do cells release energy from food

A

they respire aerobically and anaerobically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how can substances move in and out of cells

A

by diffusion, osmosis and active transport

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

what are the levels or organisation in an organism

A

organelles, cells, tissues, organs and organ systems

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

what does a catalyst do

A

speeds up the reaction without getting used up

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

what are enzymes made of

A

chains of amino acids

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

what is an active site

A

the shape of the protein molecule or enzyme.

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

what attaches to the active site

A

the substrate

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

what happens if the shape of the active site changes

A

the enzyme stops working and denatures

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

what could change the shape of the active site/denature the enzyme

A

heat or pH

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

what is the chemical energy from food (that is broken down by cellular respiration) used for?

A

muscle contraction, active transport, building up large molecules and cell division

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

give the word equation for aerobic respiration

A

glucose + oxygen –> carbon dioxide and water (+ energy)

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

give the chemical equation for aerobic respiration

A

C6H12O6 + 6O2 –> 6CO2 + 6H2O (+ energy)

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

what is anaerobic respiration caused by

A

cells having to respire with no oxygen available

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

what are the waste products of anaerobic respiration in yeast cells

A

ethanol and carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the waste products of anerobic respiration in animal cells

A

lactic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does anaerobic respiration differ from aerobic?

A

the glucose is not completely broken down and less energy is released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

where does anaerobic respiration take place

A

in muscle cells during exercise.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is oxygen debt

A

once the exercise stops, extra oxygen is needed to break down the lactic acid fully. the oxygen needed is called the oxygen debt.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is diffusion

A

net overall movement of particles from an area of high concentration to an area of low concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is diffusion caused by

A

random movement of particles in gases and liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

is diffusion passive or active

A

passive as it takes place down a concentration gradient and does not use energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is diffusion affected by

A

concentration, temperature and available surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is osmosis

A

a special type of diffusion where only water moves across a partially permeable membrane from an area of high concentration to an area of lower concentration of water down the concentration gradient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

where does osmosis take place

A

cell membranes are partially permeable, so osmosis takes place across cell membranes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is active transport

A

substances are moved against a concentration gradient or across a selectively permeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

where does active transport get energy from

A

cellular respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

features of a nerve cell that adapts it for its function

A

elongated axon for carrying nerve impulses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

features of a smooth muscle cell that adapts it for its function

A

elongated, can contract to move food through the gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

features of a sperm cell that adapts it for its function

A

tail for swimming, the head contains genes from the father and the middle contains mitochondria for energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

features of a guard cell that adapts it for its function

A

special shape results in pore between the cells for gas exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

features of a leaf palisade cell that adapts it for its function

A

packed full of chloroplasts for photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

features of a root hair cell that adapts it for its function

A

has a hair like filment to increase the surface area for osmosis to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

plants:

A

multicellular and carry out photosynethesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

animals:

A

multicellular and feed on living organisms to get their energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

fungi:

A

multicellular or unicellular, absorb food from other living organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

protoctists:

A

single-celled organisms, mainly microscopic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

bacteria:

A

single-celled organisms, much smaller than protoctists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

viruses:

A

even smaller than bacteria, and are parasites that reproduce inside other living cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

examples of a plant

A

maize, peas, ferns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

examples of an animal

A

humans, insects and worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

examples of fungi

A

moulds, yeast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

examples of protoctists

A

protozoa, algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

examples of bacteria

A

lactobacillius, pneumcoccus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

how do plants capture energy from the sun

A

using chlorophyll in their chloroplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what do plants store carbohydrates as

A

starch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

can animals carry out photosynthesis

A

no as they dont contain chlorophyll

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what do animals store carbohydrates as

A

glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

how do animals use coordination

A

they have nervous systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what are vertebrates

A

animals that have a backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what are animals that dont have a backbone called

A

invertebrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

what are fungal cell walls made of

A

chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

what are multicellular fungi made up of

A

a mycelium

60
Q

what is a mycelium

A

a tangled network of thread like structures called hyphae

61
Q

what is saprophytic nutrition

A

the secretion of enzymes by fungi which digest their load outside the cells, and then absorb the digested products. many fungi acts as composers

62
Q

how do protoctists make their food

A

by photosynthesis (algae) or feeding on other organisms (protozoa)

63
Q

what is plasmodium

A

a protoctist that causes malaria

64
Q

what are prokaryotes

A

single celled organisms that do not have a nucleus

65
Q

common shapes of bacteria

A

spheres, rods and spirals

66
Q

what is a bacteria cell wall made of

A

polysaccharides and proteins

67
Q

what organelle do bacteria not have

A

nucleus

68
Q

where is the genetic material in bacteria

A

in a circular loop in the cytoplasm

69
Q

what are plasmids

A

small extra circles of DNA in bacteria

70
Q

can bacteria photosynthesize?

A

some contain chlorphyll and can, some feed off dead or other living organisms.

71
Q

what do some bacteria have for movement

A

flagella

72
Q

what do some bacteria have for protection

A

slime capsules

73
Q

what is smaller, virus or bacteria

A

virus

74
Q

where can viruses reproduce

A

inside the living cells of a host

75
Q

what is the structure of a virus

A

core of genetic material surrounded by a protein coat. they either contain RNA or DNA, but not both.

76
Q

can all living organisms be infected by viruses

A

yes including bacteria

77
Q

each type of virus causes….

A

one specific disease in the paticular organism it is adapted to infect.

78
Q

which cells dont have a nucleus

A

red blood cells, xylem

79
Q

what does a nucleus contain

A

the chromozones which carry the carry the genetic material/genes (DNA)

80
Q

where are proteins made

A

the instructions for making proteins are carried out of the nucelus into the cytoplasm, where the proteins are assembled on tiny structures called ribosomes

81
Q

what controls the chemical reactions that take place in a cell

A

enzymes

82
Q

if the cell membrane can control the movement of substances what is it

A

selectively permeable (not partially permeable)

83
Q

what organelle is found in the cytoplasm of all living cells

A

mitochondria.

84
Q

what do mitochondria do

A

carry out some of the reactions of respiration, releasing energy the cell can use

85
Q

what does cell wall help the plant to do

A

keep its shape and is why a plant has a fixed shape.

86
Q

what is cellulose

A

a carbohydrate

87
Q

why does a plant need a cell wall

A

plant cells absorb water, producing an internal pressure that pushes against adjacent cells, giving the plant support. without cell walls strong enough to resist this it wouldnt be possible

88
Q

if the cell wall is porous, (so it is not a barrier to water or dissolved substances), what do we call this

A

freely permeable

89
Q

what does a vacuole contain

A

cell sap - sugars, mineral ions and other soutes.

90
Q

why do we even need enzymes

A

the internal body temperature of humans is 37 degrees, so without a catalyst, all of the reactions that happen in cells would be too slow to allow life to go on.

91
Q

what happens when the substrate joins up with the wnzymes active site

A

it lowers the energy needed for the reaction to start

92
Q

optimum temp for enzymes

A

37 degrees

93
Q

when do proteins start getting broken down by heat

A

above 40 degrees

94
Q

is denaturing permenant

A

yes

95
Q

pH inside cells and optimum pH for enzymes

A

7

96
Q

what pH does pepsin have

A

2 (stomach)

97
Q

how do you calculate rate of reaction

A

divide volume of (e.g. starch/what changes)
by the time it took (to change)

cm cubed divided by min or seconds

98
Q

what are buffer solutions

A

solutions of salt that resist changes in PH.

99
Q

what are buffer solutions used for

A

finding the effect of pH on exnzyme activity

they can also be prepared for maintaining different values of pH

100
Q

practcal fto dind the effect of pHon catalase

A

potato is chopped into small pieces and placed in blender with an equal vol of distilled water. this release catalase from the cells. the debris sinks to the bottom and the liquid extract is removed. the extract is tested for catalase activity using a graduated syringe containing 5cm cubed of it. 5cm cubed of buffer solution pH 7 is also added. its shaken to mix the potato extract ith the buffer solutiona dn left for 5 minutes. then 5cm cubed of hydrigen oerizude solution is added and a bung is inserted and the end of the delivery tube put into a beaker of warer. bubbles willbe produced. the number of bubbles per minute is a measure of the inital reaction rate.

101
Q

what is ATP used for

A

contraction of muscle cells
active transport of molecules and ions
building large molecules like proteins
cell division

102
Q

the energy released as heat in repsiration is used to

A

maintina internal body temperature

103
Q

aerobic respiration equation

A

C6H12O16 + 6O2 = 6CO2 + H2O (+energy)

104
Q

how do cells pass energy to eachother

A

using a chemical called adenosine triphosphate or ATP

105
Q

what is ATP

A

an organic molecule (adenosine) attached to three phosphate groups. it can be broken down by losing one phosphate group and forming adenosine diphosphate

106
Q

what happens when energy is needed

A

ATP is broken down into ADP and phosphate. during respiration it is made from the ADP AND the phosphate

107
Q

during the breaking down of ATP, what is released

A

chemical energy which can be used to drive metabolic processes that need it

108
Q

plants

A

multicellular
contin chloroplasts and can carry out photosynthesis
cellulose cell wallas
store carbohydrates as starch or sucrose

109
Q

animals

A

multicellular
no chloroplasts (no photosyntheisis)
nervous coordination
store carbohydrates as glycogen

110
Q

fungi

A 
mycelium made of hyphae which contain many nuclei
some are single celled
cell walls of chitin
saprotrophic nutrition
store carbohydrates as glycogen
111
Q

protoctists

A

microscopic single celled organisms.

112
Q

bacteria

A 
microscopic single celled organisms
cell wall 
cell membrane
cytoplasm
plasmids
no nucleus but contain a circular chromozone of DNA
no photosynthesis
feed off other living or dead organisms
113
Q

virus

A 
not licing
smaller than bacteria
can only reproducei nsideliving vells
no cellular structure
protein coat and contain one type of nucleic acid (RNA or DNA)
114
Q

practical for the demonsration of the production of CO2 using small licving organims

A

put the small organisms in a stoppered boiling tube on the gauze platform with the indicator. the hydrogen carbonate indicator will fo yelllow (from orange) with tuhe production of carbon dioxide

115
Q

practical for the demonstration that heat is produced in respiration

A

soak peas in water for 24 hours so they germinate.
boil other peas to kill them. each set is washed in 1% bleach solution, which acts a as a disinfectant to kill any bacteria on the surface. rinsed twice in distilled water to remove any traces of bleach. put them each in an inverted vaccuum flask with some air, it will insulate the contents so that any small temp change can be measured. the seeds produce CO2 which is denser than air. the inverted flask and cotton wool allow it to escae or it would kill the peas.

116
Q

what is rate of diffusion affected by (4)

A

conc gradient
surfave area to volume ratio
distance over which diffusion takes place
temperature

117
Q

practical for demonstration of diffusion in a jelly

A

petri dish contains 2cm deep of agar jelly, dyed purple with potassium permanganate/ three cubes are cut out with side lengths 2cm,1cm and 0.5 cm. they have different surface area to volumes ratio. drop them into a beaker of dilute HCl. when HCl comes into contact with potassium permanganate it goes colourless, so note the time.

118
Q

what is active transport

A

movemnet of substances against a conc gradient using energy from respiration

119
Q

adaptation def

A

when the structure of a cell or organism is suited to its function.

120
Q

what do multicellular organisms start off as

A

a zygote, which then divides into 2 cells, then 4, then 8 an dso on. this is called mitosis.

121
Q

what is the specialisation of cells as they divide called

A

differentiation.

122
Q

7 main systems in the human body

A 
digestive system 
gas exchange systm
circulatory system
excretory system
nervous system
endocrine system
reproductive system
123
Q

stem cells

A

paper two

124
Q

what are extracellular enzymes

A

enzymes secreted out of cells for the purpose of saprotophic nutrition

125
Q

is the hyphae divided into separeate cells

A

no the thread like mucor have cell walls surrounding the cytoplasm. tge cytoplasm contians many nuceli

126
Q

what does eukaryotic mean

A

having a nucleus. eurkaryotic organisms have cells contiaing a nucleus surrounded by a membrane alonf with other membrane bound organelles, such as mitochondria or chlorplasts.

127
Q

what does prokaryotic mean

A

before nucleus, these organisms’ cells have no nucleus mitochondria or chloroplasts.

128
Q

three basic shapes of bacteria

A

spheres, rods and spirals

129
Q

what are bacterial cells walls made o

A

a complex compound of sugars and proteins called peptidoglycan

130
Q

how can some bacteria swim

A

they have flagella

131
Q

what are plasmids

A

small circular rings of DNA, carrying some of the bacteria’s genes

132
Q

whats inside a virus

A

core of genetic material surrounded by a protein coat. the genetic material is either DNA or RNA.

133
Q

how does a virus produce

A

a virus can only reproduce inside another living organism or host cell, by taking over its genetic machinery. when the host dies from too many virus particles, the particles are used to infect more cells. this does not continue forever because the humans immune system can destroy viruses, if it cant the virus will kill the organism. some viruses attack the immune system itself.

134
Q

give three ways in which viruses differ from other living organisms (3)

A

no organelles: no cytoplasm, no mitochondria
can only reproduce in other living cells
protein coat

135
Q

what do multicellular organisms begin life as

A

zygote

136
Q

what does the zygote divide into

A

two cells, then four, then eight and son on until the adult body contians countless millions of cells (mitosis)

137
Q

what is division of the zygote called

A

mitosis

138
Q

outline the process of mitosis of the zygote

A
  1. chromosomes in the nucelus are copied
  2. the nucleus splits in two (genetic info shared equally)
  3. the cytoplasm divides (or new cell wall develops in plants)
  4. and they take in food substances to supply energy and building materials so they can grow to full size
  5. repeat. cells become specialised to carry out particular roles. this is called differentiation
139
Q

what do cells all have in common

A

they all have the same genes. for cells to function differently, they must produce different proteins and different genus codes for the production of different proteins.

140
Q

what are stem cells

A

has the ability to divide many times by mitosis while remaining undifferentiated. later it can differntiate into specialised cells such as muscle or nerve cells.

141
Q

what are the two types of stem cells in humans

A

embryonic stem cells

adult stem cells

142
Q

where are embryonic stem cells found

A

in the early stage of development of the embryo. they can differentiate into any type of cell.

143
Q

where are adult stem cells found

A

certain adult tissues like bone marrow, skin and the lining of intestines. they can only form other specialised tissues. e.g. bone marrow cells can divide many times but are only able to produce different types of red and white blood cells

144
Q

what is stem cell therapy

A

using stem cells to to treat a disease or repair damaged tissues.

145
Q

what are bonemarrow transplants used to treat

A

blood cancers

146
Q

what are scientists doing with embryonic stem cells

A

isolating and culturing them. they are obtained from fertility clinics where parents choose to donate their unused embryos for research.

edexcel igcse biology (5 decks)

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