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paper one Flashcards

1
Q

what do living organisms need to do to be considered living?

A

Movement
Respiration
Sensitivity (respond to surroundings)
Homeostasis
Grow
Reproduce
Excrete
Nutrition

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2
Q

are plants multicellular or unicellular?

A

multicellular

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3
Q

are animals multicellular or unicellular?

A

multicellular

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4
Q

are fungi multicellular or unicellular?

A

usually multicellular but some are unicellular

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5
Q

what are plant cell walls made of?

A

cellulose

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6
Q

what are fungi cell walls made of?

A

chitin

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7
Q

what do plants store carbohydrates as?

A

starch

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8
Q

what organelles do plants have that animals don’t have?

A
  • chloroplasts
  • cell walls
  • vacuoles
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9
Q

what organelles do both animal cells and plant cells have?

A
  • cytoplasm
  • cell membrane
  • mitochondria
  • nucleus
  • ribosomes
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10
Q

what do animals (usually) store carbohydrates as?

A

glycogen

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11
Q

what are fungi normally organised as?

A

mycelium made from hyphae (thread like structures) which contain many nuclei

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12
Q

what kind of digestion do fungi use?

A

saprotrophic digestion

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13
Q

what is saprotrophic digestion?

A

digestive enzymes are secreted outside of the cell onto the food, which is then broken down into small soluble molecules and absorbed by the decomposer

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14
Q

can fungi photosynthesise?

A

no

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15
Q

do animals have nervous coordination?

A

yes

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16
Q

what are some examples of fungi?

A
  • mucor (typical hyphal structure)
  • yeast (single-celled)
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17
Q

are protoctists multicellular or unicellular?

A

normally unicellular

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18
Q

what are two examples of protoctists?

A
  • amoeba (animal-like)
  • chlorella (plant-like)
  • plasmodium (pathogenic - responsible for malaria)
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19
Q

are bacteria multicellular or unicellular?

A

unicellular

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20
Q

what organelles do bacteria have?

A
  • cell wall
  • cell membrane
  • cytoplasm
  • plasmids (circular chromosome of DNA)
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21
Q

can bacteria photosynthesise?

A

some can but most feed on other dead or living organisms

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22
Q

what are two examples of bacteria?

A
  • lactobacillus bulgaricus (yoghurt making)
  • pneumococcus (pathogen for pneumonia)
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23
Q

which kingdoms can be pathogenic?

A

bacteria, viruses, fungi, protoctists

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24
Q

what are pathogens?

A

a pathogen are microorganisms which cause infectious disease. they harm the host by releasing toxins or damaging cells
all viruses are pathogens; fungi, bacteria and protoctists can be pathogenic (but not all of them are)

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25
Q

how big are viruses?

A

smaller than bacteria

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26
Q

what do viruses need to reproduce?

A

a host cell

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27
Q

can viruses infect every type of living organism?

A

yes

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28
Q

what makes up a virus cell?

A
  • no cellular structure
  • protein coat
  • one type of nucleic acid (either DNA or RNA)
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29
Q

what are three examples of viruses?

A
  • tobacco mosaic virus (causes discolouration of leaves of tobacco plants by preventing chloroplasts from forming)
  • influenza (causes the flu)
  • HIV (causes AIDS)
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30
Q

what are organelles?

A

small structures in the cell with a specific function

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31
Q

what are cells?

A

smallest functioning unit of life, contain organelles to carry out a specific function

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32
Q

what are tissues?

A

a group of similar cells working together to carry out the same function

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33
Q

what are organs?

A

made up of several different tissues working together to carry out a more complex function

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34
Q

what are organ systems?

A

made up of several different organs working together to carry out a complex function essential for life

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35
Q

what is the function of a nucleus?

A

controls the activity of the cell by making proteins, contains the chromosomes

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36
Q

what is the function of cytoplasm?

A

jelly-like liquid where chemical reactions occur

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37
Q

what is the function of mitochondria?

A

site of aerobic respiration

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38
Q

what is the function of the ribosomes?

A

protein synthesis from amino acids

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39
Q

what is the function of the chloroplasts?

A

site of photosynthesis

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40
Q

what is the function of cell walls?

A

keeps the shape of the cell, prevents the cell from bursting

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41
Q

what is the function of the cell membranes?

A

controls what goes in and out of the cell (selectively permeable)

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42
Q

what is the function of the vacuole?

A

contains cell sap, stores dissolved sugars, mineral ions, and other substances

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43
Q

what chemical elements are in carbohydrates?

A

CHO

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44
Q

what chemical elements are present in proteins?

A

CHON

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45
Q

what chemical elements are present in lipids?

A

CHO

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46
Q

what is starch and glycogen made up of?

A

glucose (simple sugars)

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47
Q

what are proteins made up of?

A

amino acids

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48
Q

what are lipids made of?

A

fatty acids and glycerol

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49
Q

how do you test for glucose?

A
  1. place a small sample (approx. 2cm^3) of food in a test tube
  2. then add 1cm^3 of Benedict’s solution, or enough for it to appear blue
  3. then heat in an 85 degree celcius water bath for 5 minutes
  4. if the mixture turns from blue to green/yellow/orange/brick red then sugar is present
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50
Q

how do you test for starch?

A
  1. take a small sample of food and place it in a well on a spotting tile
  2. add 10 drops of iodine solution/a roughly equal amount of iodine to food
  3. if starch is present, the iodine changes from orange to black/blue
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51
Q

how do you test for proteins?

A
  1. place a small food sample in a test tube
  2. add a roughly equal amount of Biuret solution or enough for the pale blue colour to be seen
  3. if the mixture turns from blue to mauve/purple, proteins are present
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52
Q

how do you test for lipids?

A
  1. place a small food sample in a test tube
  2. add roughly equal amount of ethanol and mix well
  3. add roughly equal amount of water (1:1:1) and mix well again
  4. if the mixture turns milky, fat is present
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53
Q

what is the role of enzymes?

A

biological enzymes in metabolic reactions

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54
Q

how do temperature changes affect enzymes?

A

as temperature increases, the enzymes and the substrate get more kinetic energy, so more enzyme-substrate complexes are formed as there are more collisions. as the temperature increases past the optimum temperature, enzymes denature, bc they have too much kinetic energy so the enzyme’s active site changes shape, so the substrate can no longer fit (is no longer complimentary), so there are less/no enzyme-substrates complexes formed

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55
Q

how would you test to see how temperature change affects enzymes?

A
  1. place single drops of iodine solution in rows on the spotting tiles
  2. label a test tube with the temperature to be tested (eg. 10 degrees celcius)
  3. use cold water from the tap and hot water from the kettle to prepare a water bath at that temperature, and keep it at that temperature for the test using a thermometer
  4. use a syringe to place 2cm^3 of amylase into the test tube, then place it in the water bath for 5 minutes
  5. use another syringe to add 2cm^3of starch solution to the amylase solution (leaving the test tube in the water bath) start the stop watch and mix using the pipette
  6. after 30 seconds, use the pipette to squirt one drop of iodine solution into the first drop of iodine, the squirt the rest of the pipette back in the test tube. the iodine solution should turn blue/black
  7. after another 30 seconds, drop another drop of the solution into the next iodine drop
  8. repeat step 7 until the iodine stays orange
  9. count how many iodine drops you used, each equals 30 seconds of reaction time
  10. repeat 1-9 for each temperature (eg 20, 30, 40, 50, 60)
  11. repeat each temperature 3 times and work out a mean
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56
Q

how does change n pH affect enzyme activity?

A

as the pH increases up to the optimum, the enzyme’s active site becomes more complimentary to it’s substrate, so enzyme activity increases. after it reaches the optimum, the active site changes shape and so the enzyme denatures so enzyme activity decreases/stops

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57
Q

what is diffusion?

A

the random movement of particles from an area of high concentration to low concentration

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58
Q

what is osmosis?

A

the net diffusion of free water molecules from an area of high water potential to low water potential across a partially permeable membrane

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59
Q

what is active transport?

A

the movement of molecules from an area of low concentration to high concentration using ATP

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60
Q

how does sa:v affect diffusion?

A

the smaller the sa:v is, the higher the rate of diffusion is

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61
Q

how does distance affect diffusion?

A

the greater the distance, the lower the rate of diffusion

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62
Q

how does temperature affect diffusion?

A

the greater the temperature, the higher the rate of diffusion

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63
Q

how does concentration gradient affect diffusion?

A

the higher the concentration gradient is, the higher the rate of diffusion is

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64
Q

how do you investigate osmosis in living systems?

A
  1. use a cork borer to cut equal cylinders in a potato
  2. cut the cylinders the same length (about 3cm) - have five
  3. measure and record the mass of each
  4. measure out 10cm^3 of 0M, 2.5M, 5M, 7.5M, 1M sucrose solution into 5 different test tubes
  5. add one potato cylinder (of known mass) into each tube
  6. leave for 30 minutes
  7. take out each potato and gently dry them by tapping them with a paper towel then weigh them and record the new mass for each
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65
Q

how do you investigate osmosis in a non-living system?

A

connect a visking tube to a capillary tube, and fill the visking tube with sucrose solution and put into a beaker with 20 cm^3 of water. leave for 30 mins, then measure the volume of water. repeat with different concentrations of sucrose solution

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66
Q

how do you investigate diffusion in non-living systems?

A

put potassium permanganate crystals in a beaker of water. observe after 15 minutes, then observe after 1 hour

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67
Q

what does photosynthesis do?

A

convert light energy into chemical energy

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68
Q

what is the word equation for photosynthesis?

A

water + carbon dioxide –light–> oxygen + gluose

69
Q

what is the balanced chemical equation for photosynthesis?

A

6CO2 + 6 H2O –> 6O2 + C6H12O6

70
Q

how does varying carbon dioxide concentration affect the rate of photosynthesis?

A

a higher concentration of carbon dioxide increases the rate of photosynthesis because there are more molecules for the enzymes to collide with
at a certain point, increasing the concentration doesn’t change anything, as it is no longer the limiting factor

71
Q

how does varying light intensity affect the rate of photosynthesis?

A

increasing the light intensity increases the rate of photosynthesis because there is more energy for the reaction to occur
at a certain point increasing the light intensity doesn’t change anything because something else has become the limiting factor

72
Q

how does varying temperature affect the rate of photosynthesis?

A

enzyme shape

73
Q

how are leaves specialised for photosynthesis?

A
  • large surface area + thin
  • upper epidermis is transparent
  • palisade cells are long, thin, and tightly packed
  • stomata allow gasses to diffuse into the air spaces of leaf
  • xylem transports water into leaf
  • phloem vessel transports sugars
74
Q

how does the large surface area and thinness of a leaf help in photosynthesis?

A
  • maximises absorption of sunlight by cells
  • increases number of stomata so carbon dioxide can diffuse quicker
75
Q

how does the upper epidermis being transparent help photosynthesis?

A

allows light to penetrate the palisade mesophyll

76
Q

how does the palisade cells being long, thin, ad tightly packed together help photosynthesis?

A

contain lots of chloroplasts which maximises the absorption of sunlight energy - palisade is the main site of photosynthesis

77
Q

how do the stomata help photosynthesis?

A

provides a short diffusion distance for carbon dioxide because it allows gasses to diffuse into the air spaces of the cell

78
Q

how do the xylem helo ohotosynthesis?

A

provide a short diffusion distance for water

79
Q

what do plants require for growth?

A

mineral ions

80
Q

what are magnesium ions needed for in plants?

A

chlorophyll

81
Q

what are nitrate ions needed for in plants?

A

making amino acids

82
Q

what is the symptom of deficiency of nitrate ions in plants?

A

stunted growth

83
Q

what are phosphate ions needed for in plants?

A

needed to make nucleic acids and part of the cell membrane

84
Q

what is the symptom of deficiency of magnesium ions in plants?

A

yellow leaves

85
Q

what is the symptom of deficiency of phosphate ions in plants?

A

poor root growth or purple younger leaves

86
Q

how can you investigate the effect of light intensity on photosynthesis?

A
  1. place the beaker of pondweed 10cm away from the light source
  2. count the number of bubbles produced in one minute (using a stopwatch
  3. repeat twice more and record the mean
  4. repeat 1-3 for 4 more distances, eg. 15cm, 20cm, 25cm, 30cm
  5. record the results in a table
87
Q

how can you investigate the effect of carbon dioxide concentration on photosynthesis?

A
  1. de-starch the plant by putting it in a dark cupboard for 24 hours
  2. put a conical flask containing potassium hydroxide around one leaf, this will absorb the carbon dioxide in the air
  3. put an empty conical flask around another leaf as a control test
  4. place the plant in a bright place
  5. test both leaves for starch using iodine solution (drop it in boiling water, place it in hot ethanol for 5-10mins, spread on a white tile and drop iodine solution over it)
88
Q

how would you investigate the effect of chlorophyll on photosynthesis?

A
  1. use a variegated leaf
  2. put the leaf in boiling water for 30 seconds to kill the tissue and break down cell wall
  3. put the leaf in a boiling tube of hot ethanol for 5-10mins to remove the chlorophyll so the colour can be seen more easily
  4. rinse the leaf under cold water to soften it
  5. spread it out on a white tile and use iodine to test for starch, the white parts should stay orange and the green parts will turn blue/black
89
Q

what are the components of a balanced diet?

A
  • carbohydrates
  • proteins
  • lipids
  • vitamins
  • minerals
  • water
  • dietary fibre
90
Q

what are the functions of carbohydrates?

A
  • direct source of energy
  • fuel for respiration
91
Q

what is the function of dietary fibre?

A
  • provides bulk for intestines to push food through it
  • prevents bowel cancer and constipation
92
Q

what is the function of lipids?

A
  • storing and providing energy
  • thermal and electrical insulation
  • fuel for respiration
93
Q

what is the function of protein?

A
  • repairs and builds tissues
  • fuel for respiration
94
Q

what is the function of vitamin a?

A
  • making a chemical in the retina and keeping the retina healthy
  • protects the surface of the eye
  • prevents night blindness
95
Q

what is the function of vitamin c?

A
  • needed for cells and tissues to stick together
  • prevents scurvy
96
Q

what is the function of vitamin d?

A
  • needed to absorb calcium and phosphate ions from food
  • prevents rickets
97
Q

what is the function of iron?

A
  • forms part of haemoglobin
  • prevents anaemia
98
Q

what is the function of calcium?

A
  • needed to form bones and teeth
  • prevents osteoporosis and rickets
99
Q

what is the function of water?

A

it is an essential solvent, transports components of blood, is essential for temperature regulation

100
Q

what are some sources of carbohydrates?

A
  • bread
  • rice
  • fruits
  • potatoes
  • cereals
101
Q

what are some sources of dietary fibre?

A
  • fruits
  • veggies
  • grains
102
Q

what are some source of lipids?

A
  • butter
  • cooking oil
  • avocado
  • cream
103
Q

what are some sources of protein?

A
  • meat
  • fish
  • eggs
  • quinoa
  • quorn
104
Q

what are some sources of vitamin a?

A
  • fish oils
  • liver
  • butter
  • carrots
105
Q

what are some sources of vitamin c?

A

fresh fruits and veggies

106
Q

what are some sources of vitamin d?

A
  • dairy products
  • oily fish
107
Q

what are some sources of iron?

A
  • red meat
  • liver
  • spinach
108
Q

what are some sources of calcium?

A
  • milk and dairy products
  • fresh fruits
  • fish
109
Q

what are some sources of water?

A
  • water
  • cucumber
  • lettuce
110
Q

what is the function of the mouth?

A

mechanical digestion, increasing the surface area of food (by making it into bolus), salivary amylase breaks down starch into maltose, saliva makes food easier to swallow

111
Q

what is the function of the oesophagus?

A

mechanical digestion; peristalsis occurs to push bolus down towards the stomach

112
Q

what is the function of the stomach?

A

chemical digestion: pepsin from stomach walls to break down proteins into peptides, mechanical digestion by muscle churning, stomach acid lowers pH for pepsin and sterilises food

113
Q

what is the function of the duodenum?

A

chemical digestion - contains many enzymes (amylase, lipase, protease)

114
Q

what is the function of the ilieum?

A

chemical digestion - enzymes break down food
villi and microvilli to absorb nutrients

115
Q

what is the function of the colon?

A

reabsorbing water to form faeces

116
Q

what is the function of the rectum?

117
Q

what is the function of the pancreas?

A

secretes enzymes into stomach and small intestine for chemical digestion

118
Q

how is food moved through the gut?

A

peristalsis

119
Q

what enzymes are in the mouth?

A

salivary amylase
starch –> maltose

120
Q

what kind of enzymes are there in the stomach?

A

pepsin (protease)
proteins –> peptides

121
Q

what enzymes are produced in the pancreas?

A

pancreatic amylase, trypsin (protease), pancreatic lipase

122
Q

what kind of enzymes are there in the duodenum?

A

pancreatic amylase, trypsin (protease), pancreatic lipase
starch –> maltose
peptides –> amino acids
lipids –> fatty acids + glycerol
in the walls (gets secreted out):
maltase
maltose –> glucose

123
Q

what kind of enzymes are there in the ilieum?

A

(in the walls and gets secreted out)
maltase
maltose –> glucose

124
Q

where is bile produced?

125
Q

where is bile stored?

A

the gall bladder

126
Q

what is the role of bile?

A

emulsifies lipids, neutralises stomach acid

127
Q

how is the small intestine adapted for absorption?

A

thin cell wall - decreases diffusion distance for soluble molecules
large surface area to volume ratio - villi increases surface area for diffusion
large network of capillaries - maintain the concentration gradient

128
Q

what does respiration produce?

129
Q

what does ATP provide for cells?

130
Q

what is the difference between aerobic and anaerobic respiration?

A

aerobic: with oxygen, produced carbon dioxide + water, produces more ATP
anaerobic: without oxygen, produces lactic acid (in animals)

131
Q

what is the word equation for aerobic respiration?

A

oxygen + glucose –> carbon dioxide + water (+ATP)

132
Q

what is the balanced chemical equation for aerobic respiration?

A

6O2 + C6H12O6 –> 6CO2 + 6O2

133
Q

what is the word equation for anaerobic respiration in animals?

A

glucose –> lactic acid

134
Q

what is the word equation for anaerobic respiration in plants (and fungi)?

A

glucose –> ethanol + carbon dioxide

135
Q

what is the method to investigate the evolution of carbon dioxide from respiring seeds (or other organisms)?

A
  1. pour some sodium hydroxide solution into the first conical flask. this is connected to the pipe that allows the inflow of air and removes the carbon dioxide from the air
  2. pour some hydrogen carbonate indicator in the second flask. this is connected to the first flask with a delivery tube
  3. place the respiring seeds in the third conical flask on some moist cotton. this is connected to the second conical flask
  4. pour some hydrogen carbonate indicator in the fourth flask, which is connected to the pipe to allow the outflow of air
  5. observe the colour of the hydrogen carbonate indicator
136
Q

what colour does hydrogen carbonate indicator go in carbon dioxide?

137
Q

what is the method to investigate the evolution of heat from respiring cells (and other organisms)?

A
  1. set up two thermoflasks
  2. place the respiring seeds with cotton wool in one of the thermoflasks
  3. place the boiled seeds with moist cotton wool in the other thermoflask
  4. use a thermometer to measure and record the initial temperature
  5. after a certain number of days, measure and record the final temperature and work out the temperature difference
138
Q

what are the ribs?

A

bone structures that protect internal organs (including lungs)

139
Q

what are the intercoastal muscles?

A

muscles in between the ribs that move the ribs during inhalation and exhalation

140
Q

what is the diaphragm?

A

a sheet of muscle at the bottom of the thorax that changes the volume of the thorax

141
Q

what is the trachea?

A

wind pipe that connects the mouth + nose to the lungs

142
Q

what are the bronchi?

A

thick tubes that divide into two bronchi in the lungs (one bronchus for each lung)

143
Q

what are the bronchioles?

A

the bronchi will split to form them and are connect the bronchi to the alveoli

144
Q

what are the alveoli?

A

air sacs where gas exchange occurs

145
Q

what are the pleural membranes?

A

the thin moist membrane lining the outside of the lungs for lubrication to reduce friction, and to stick outside of lungs to chest cavity for lungs to follow chest movement

146
Q

what happens during inhalation?

A

diaphragm contracts so it moves down and flattens, the intercostal muscles contract, which pulls the ribs up and out
volume of thorax increases, air pressure falls. the air pressure in the thorax is now lower than the atmospheric pressure, so air moves into the lungs

147
Q

what happens during exhalation?

A

the diaphragm relaxes so it moves up and domes, the intercostal muscles relax, which makes the rib cage move down and in
the volume of the thorax decreases so air pressure rises. air pressure in the thorax is higher than atmospheric pressure so air moves out of the lungs

148
Q

how are the alveoli adapted for gas exchange?

A

they have a large surface area to volume ratio which increases the rate of diffusion
they are surrounded by a network of capillaries which keeps the concentration gradient high
each alveolus is one cell thick which shortens the diffusion distance

149
Q

what is the effect of smoking on the air passages?

A
  • tar in cigarettes destroys cilia (which gets rid of dust and microbes trapped in mucus) so it causes a build up of mucus, and increased risk of bronchitis
  • tar in cigs contains carcinogens which increases risk of lung cancer
150
Q

what is the effect of smoking on the alveoli?

A

tar in cigs breaks down alveoli walls and makes them merge together, so it increases the surface area : volume
insufficient gas exchange will increase the risk of emphysema - shortness of breath due to insufficient oxygen transport in blood

151
Q

what effect does smoking have on the circulatory system?

A
  • nicotine in blood vessels cause the blood vessels to narrow, placing strain on circulatory system and results in increased blood pressure
  • narrowing of blood vessels also cause the build up of fat globules, increasing the risk of coronary heart disease (CHD).
  • the carbon monoxide from cigarette smoking will bind irreversibly to haemoglobin, reducing the amount of oxygen that can be carried in red blood cells, so it increases risk of emphysema (shortness of breath due to insufficient oxygen transport)
152
Q

what is coronary heart disease?

A

it is when the lumen of the coronary arteries is blocked with fat, and irritation of the lining of the arteries causes it to harden until lumen is blocked. this means there’s less oxygen taken to the heart, so there is more anaerobic respiration, so lactic acid is produced which causes chest pains (angina). this means less atp is formed, so the muscles stop contracting and die, causing a heart attack

153
Q

what is the method to investigate breathing in humans and the release of carbon dioxide?

A
  1. pour lime water into a boiling tube
  2. using the straw, breathe into it
  3. note the change in limewater
154
Q

what is the method to investigate breathing in humans and the effect of exercise?

A
  1. measure the breathing rate of the person at rest (breaths/minute)
  2. carry out a specific exercise, like star jumps, for 1 minute
  3. measure the breathing rate immediately after
  4. repeat 2-3 for different intensities of exercise (still the same thing though)
155
Q

why can simple unicellular organisms rely on diffusion for movement of substances in/out of the cell?

A

they have a large surface area to volume ratio (because of size and often shape) so very efficient for diffusion, unicellular organisms also often have moist membranes to allow substances to diffuse easily

156
Q

why do multicellular organisms need a transport system?

A

they have a small surface area to volume ratio so diffusion is insufficient and they can’t rely on diffusion to transport necessary substances, so they require a transport system to provide a constant supply of a necessary substance

157
Q

what is the role of the phloem?

A

transporting sucrose and amino acids between the leaves and other parts of the plant, can flow both ways

158
Q

what is the role of the xylem?

A

transporting water and mineral ions from the roots to other parts of the plant, can only move up

159
Q

what is the composition of the blood?

A
  • red blood cells
  • white blood cells
  • platelets
  • plasma
160
Q

what is the role of plasma?

A
  • transport of waste carbon dioxide produced by aerobic respiration to the lungs for exhalation
  • transports digested food to respiring for assimilation in the form of simple sugars (eg glucose) and amino acids
  • transports urea from the liver to the kidney for excretion
  • transports hormones made by the endocrine system to target organs to stimulate change
  • maintains constant body temperature
161
Q

how does plasma maintain body temperature?

A

mainly composed of water which has a high specific heat capacity which allows plasma to maintain a constant body temperature for optimum enzyme activity

162
Q

how are red blood cells adapted to be suitable for transport of oxygen?

A
  • haemoglobin
  • no nucleus
  • small and flexible
  • thin cell membrane
  • biconcave
163
Q

why do red blood cells contain haemoglobin

A

haemoglobin binds with oxygen to form oxyhaemoglobin to transport oxygen to respiring cells

164
Q

why do red blood cells have no nucleus?

A

allow more space for haemoglobin to bind with more oxygen

165
Q

why are red blood cells small and flexible?

A

to allow them to squeeze through narrow capillaries and blood vessels for efficient transport

166
Q

why do red blood cells have a thin cell membrane?

A

makes diffusion of oxygen more efficient because it shortens the diffusion distance

167
Q

why do red blood cells have a biconcave shape?

A

increases surface area to volume ratio and decreases the distance to the centre of the cell so diffusion is more efficient/speeds up rate of diffusion

biology (10 decks)

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