Biology Igcse Edexcel

Front 1

living organisms all...

Back 1

need nutrition
respire
excrete their waste
respond to their surroundings
move
reproduce
homeostasis
grow

Front 2

plants

Back 2

multicellular
chloroplasts
photosynthesize
cellulose cell walls
store carbohydrates as starch or sucrose

Front 3

animals

Back 3

multicellular
usually have nervous co-ordination
can move from one place to another
store carbohydrate as glycogen

Front 4

fungi

Back 4

made from hyphae
hyphae have many nuclei
chitin cell walls
feed using saprotrophic nutrition
store carbohydrate as glycogen

Front 5

bacteria

Back 5

single celled
have a cell wall and plasmids
no nucleus
some carry out photosynthesis
some feed off dead organisms
have a circular chromosome of DNA

Front 6

protoctists

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single celled
microscopic

Front 7

viruses

Back 7

smaller than bacteria
parasitic
no cellular structure
have a protein coat
contain nucleic acid

Front 8

what is a pathogen?

Back 8

pathogens are things that cause diseases and can be fungi, bacteria, protoctists and viruses.

Front 9

what are carbohydrates and lipids made of?

Back 9

carbon
hydrogen
oxygen

Front 10

what are proteins made of?

Back 10

carbon
hydrogen
oxygen
sulphur
phosphorus
nitrogen

Front 11

what is the test for glucose?

Back 11

add benedict's solution then heat gently
change from blue to orange indicates glucose is present

Front 12

what is the test for starch?

Back 12

add iodine and swirl
change from red to black/blue indicates starch is present

Front 13

amylase

Back 13

breaks down of starch into maltose
is found in the mouth and small intestine
produced in the salivary glands, pancreas and small intestine

Front 14

maltase

Back 14

breaks down maltose into glucose
found in the stomach
produced in the pancreas

Front 15

proteases

Back 15

breaks down proteins into amino acids
found in the stomach and small intestine
produced in the pancreas

Front 16

lipases

Back 16

breaks down lipids into fatty acids and glycerol
found in the small intestine
produced in the pancreas and small intestine

Front 17

what factors affect enzymes?

Back 17

temperature
pH

Front 18

what is diffusion?

Back 18

the movement of substances from an area of high concentration to an area of low concentration.

Front 19

what is active transport?

Back 19

the movement of substances against a concentration gradient from low concentration to high concentration. this requires energy from respiration.

Front 20

what is osmosis?

Back 20

the movement of water molecules from an area of high water potential to an area of low water potential along a concentration gradient.

Front 21

what are turgid cells?

Back 21

cells which are swollen with water making them rigid

Front 22

what are the factors that affect the rate of movement in and out of cells.

Back 22

concentration gradient
temperature
surface area

Front 23

photosynthesis

Back 23

carbon dioxide +water = glucose + oxygen
CO2 + H2O = C6H12O6 + O2
chlorophyll and sunlight are necessary

Front 24

what factors affect the rate of photosynthesis?

Back 24

carbon dioxide concentration
temperature
light intensity

Front 25

nitrogen deficiency

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making leaves and amino acids
yellow leaves, weak stem

Front 26

magnesium deficiency

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making chlorophyll
upper leaves normal, lower leaves yellow

Front 27

phosphorus deficiency

Back 27

making roots
poor root growth, purple leaves

Front 28

potassium deficiency

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making flowers and fruit
yellow leaves with dead spots, poor fruit and flower growth

Front 29

carbohydrate

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immediate energy
bananas, brown rice, potatoes

Front 30

protein

Back 30

growth and repair
meat, sea food, spinach

Front 31

lipids

Back 31

long term energy
milk, cakes

Front 32

vitamin A

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vision and skin
yellow-orange fruit and vegetables, eggs, milk

Front 33

vitamin C

Back 33

aiding the absorption of iron and copper, helps fight infection
fruits, oranges, blackcurrants

Front 34

vitamin D

Back 34

absorption of calcium, skin
sunlight, some fish, eggs

Front 35

calcium

Back 35

bones and teeth
dairy products

Front 36

iron

Back 36

haemoglobin, myoglobin
red meats

Front 37

dietary fibre

Back 37

bowel function
cereals, bread

Front 38

water

Back 38

respiration
water

Front 39

what is digestion?

Back 39

process in which large insoluble molecules of food are broken down into smaller ones.

Front 40

what is absorption?

Back 40

the process by which soluble molecules produced by digestion are taken from the gut.

Front 41

what is assimilation?

Back 41

the cells of the tissues absorb the molecules for use

Front 42

what is excretion?

Back 42

the removal of metabolic waste products that have been in the body mainly through sweating, urine and exhaling.

Front 43

what is egestion?

Back 43

the removal of waste undigested products such as faeces.

Front 44

how is the small intestine adapted for absorption?

Back 44

villi and micro-villi give it a large surface area
there is a continuous blood supply keeping the concentration gradient high
the surface of the intestine is only one cell thick so that diffusion is quick and easy

Front 45

aerobic respiration

Back 45

glucose + oxygen = carbon dioxide + water + energy
C6H12O6 + O2 = CO2 + H2O + energy

Front 46

anaerobic respiration

Back 46

glucose = lactic acid + energy

Front 47

inhalation

Back 47

relax
internal
contract
external

Front 48

exhalation

Back 48

external
relax
internal
contract

Front 49

how are alveoli adapted?

Back 49

large surface area
thin walls
large capillary network

Front 50

what are the effects of smoking?

Back 50

cause cancerous mutations
removes cilia
hardens the arteries causing coronary disease
carbon monoxide hinder oxygen absorption

Front 51

what does the phloem do?

Back 51

transports amino acids and sucrose round the plant.
the tube like cells are alive and substances can flow both ways.

Front 52

what does the xylem do?

Back 52

transports water and dissolved minerals.
it is made up of a dead hollow column of cells.

Front 53

what affects transpiration?

Back 53

humidity
temperature
wind speed
light intensity

Front 54

what role do phagocytes play in the blood?

Back 54

ingest pathogens by encircling them and then breaking them down and releasing the broken down waste products.

Front 55

what role do lymphocytes play in the blood?

Back 55

release antibodies which are specific to each pathogen. the body remembers past pathogens using memory cells and can then quickly reproduce that antibody this is how vaccinations work.

Front 56

what role does plasma play in the blood?

Back 56

transports carbon dioxide, digested food, urea, hormones and heat energy. these substances are dissolved in water as plasma is 90% water.

Front 57

what role do red blood cells play in the blood?

Back 57

they transport oxygen for respiration.
haemoglobin
enucleate
bi-conclave

Front 58

what role do platelets play in the blood?

Back 58

cause blood clotting if there is any damage thereby preventing loss of blood. fibrin then covers the platelets in a mesh.

Front 59

arteries

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have a small hole in the centre and thick bands of muscle and tissue.
carry blood away from the heart

Front 60

veins

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have a large hole in the centre and thin bands of muscle and tissue.
carry blood towards the heart
valves along the vein stop blood flowing backwards

Front 61

capillaries

Back 61

walls only one cell thick
carry blood through tissues

Front 62

what does urine contain?

Back 62

water, salts and urea

Front 63

what is homeostasis?

Back 63

the maintenance of a constant internal environment despite external changes.

Front 64

what is geo-tropism?

Back 64

growth in response to gravity
in roots and shoots

Front 65

what is photo-tropism?

Back 65

growth in response to light
in the tips of shoots and in drought conditions

Front 66

nervous communication is...

Back 66

fast, electrical, uses nerves, short, local

Front 67

hormonal communication is...

Back 67

slow, chemical, uses blood, long, widespread

Front 68

the eye in bright light...

Back 68

radial muscles relax
circular muscles contract
the pupil is small

Front 69

the eye in dim light...

Back 69

radial muscles contract
circular muscles relax
the pupil is big

Front 70

to see near the eye...

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contracts the ciliary muscles
lengthens/slackens the suspensory ligaments
the lens is more convex

Front 71

to see far the eye...

Back 71

relaxes the ciliary muscles
ahortens/tightens the suspensory ligaments
the lens is less convex

Front 72

what does ADH do?

Back 72

pituitary gland
osmoregulation
collecting duct more permeable

Front 73

what does adrenaline do?

Back 73

adrenal glands
prepares body for physical activity
increases HR

Front 74

what does insulin do?

Back 74

pancreas
glucose regulation
liver and muscles store glucose as glycogen

Front 75

what does testosterone do?

Back 75

testes
regulates development
secondary male characteristic and maturing of sperm

Front 76

what does progesterone do?

Back 76

ovaries
regulates the menstrual cycle
maintains the uterus during pregnancy

Front 77

what does oestrogen do?

Back 77

ovaries
regulates the menstrual cycle and development
controls female secondary sexual characteristics
causes the egg to be released

Front 78

what are the characteristics of sexual reproduction?

Back 78

two parents
full number of chromosomes in the offspring
half of their chromosomes from each parent
there is variation from the parents
produced through meiosis

Front 79

what are the characteristics of asexual reproduction?

Back 79

one parent
offspring have the full number of chromosomes
all the chromosomes come from the one parent
there is no variation from the parent genetically
produced through mitosis

Front 80

what are the adaptations of insect pollinated plants?

Back 80

brightly coloured large petals
sweetly scented
contain nectar
moderate quantity of pollen
pollen is sticky/spiky
anthers inside the flower and firm
stigma inside the flower
stigma is sticky

Front 81

what are the adaptations of wind pollinated plants?

Back 81

small dull petals
no scent
no nectar
lots of pollen produced
pollen light and smooth
anthers loosely attached and dangle out
stigma hangs out
stigma is feathery or net-like

Front 82

what happens during plant pollination?

Back 82

pollen sticks to stigma
pollen grows a pollen tube downwards towards the ovary of the flower
pollen tube carries the nucleus of the pollen into the ovary
pollen fuses with an ovule (fertilisation)
petals die and fall off
ovule turns into a seed
the ovary may then produce sugars to form a fruit

Front 83

conditions necessary for seed germination...

Back 83

moisture
warm temperature
oxygen

Front 84

what methods do plants use to produce asexually?

Back 84

runners
tubers
cuttings

Front 85

what does adenine pair with?

Back 85

thymine

Front 86

what does cytosine pair with?

Back 86

guanine

Front 87

what is meiosis?

Back 87

four cells produced
each has half the number of chromosomes
haploid gametes
chromosomes switch genes before the cell switches

Front 88

what is mitosis?

Back 88

two cells produced
each has a full number of chromosomes
diploid gametes
both genetically identical to each other and the parent

Front 89

what factors increase the likelihood of a mutation occurring?

Back 89

ionising radiation
chemical mutagens
chemicals in tobacco

Front 90

how much energy is transferred from one trophic level to the next?

Back 90

10%