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1
Q

Give and example of an artificial ecosystem and explain why they have a low biodiversity

A

Forestry plantations, fish farms.
They were built for a soecific purpose, have not be established for as long as natural ecosystems, weed killers, fertilisers and pesticides are used, fewer diseases so the numbers of species are imbalanced, gewer organisms are introduced from the start.

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2
Q

What is a community?

A

The total number of individuals of all the different populations of plants and animals that live in a habitat

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3
Q

What is a population?

A

The total number of indiviuals of the same species living in a habitat

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4
Q

What is the capture-recapture method and what do you have to assume and make sure?

A

1st samp. total x 2nd samp. total
Pop. size= —————————————————
2nd sample prev. marked
You have to assume that no organisms have died, emigrated or migrated.
You have to make sure the sampling methods are identical, and that marking them doesnt effect their survival

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5
Q

What are some examples of sampling methods?

A

Pooters, sweepnets, pitfall traps, quadrats

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6
Q

What did Van Helmont do?

A

He carried out many exoeriment to conclude that plant growth isnt just from soil nutrients

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7
Q

What did Joseph Priestly do?

A

He put plants and mice in jars of air and changed the combinations to conclude that oxygen is produced by plants.

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8
Q

What can glucose and starch be converted into?

A

Energy by respiration
Proteins for growth and repair
Starch, fats and oils in seeds
Cellulose to make cell walls

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9
Q

How did scientists test that oxygen in plants came from the water and not the carbon dioxide?

A

They used radioactive oxygen-18; you only get a radioactive waste product of oxygen if the oxygen was introduced by the water

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10
Q

What are the two stages of photosynthesis?

A

Light energy is used to split water into hydrogen and oxygen then the carbon dioxide combines with the hydrogen ions to make glucose

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11
Q

When do plants respire and when do the photosynthesise?

A

Respire all the time to break down glucose and release energy and photosynthesise during the day to produce glucose when there is light to make it by breaking down water into hydrogen to react with the carbon dioxide.

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12
Q

How are leaves adapted?

A

Broad and falt to absorb sunlight, vascukar bundles for support and transportation, thin structure for gases to only travel a short distance, stomata on the underside of the leaf which can be opened and closed, transparent upper epidermis, cells in palislade layer full of chloroplasts, spongy mesophyll contains air spaces for gas exchange ans there is a very large surface area to volume ratio

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13
Q

What pigments are in leaves?

A

Chlorophyll a and b, xanthophylls, carotene

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14
Q

What is diffusion?

A

The movement of a substnace from high to low concentration

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15
Q

How is the rate of diffusion increased?

A

Greater cell membrane surface area, steeper concentration gradient, shorter distance for particles to travel

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16
Q

What is osmosis?

A

The diffusion of water (net movement) from a high to low concentration through a partially permeable membrane. It happens because the solute molecules cant pass through the membrane.

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17
Q

What happens to animal cells if they absorb too much or too little water and why?

A

Lysis - bursting from too much water
Crenation - shrivel up from too little water
It happens because animals cells do not have an inelastic cell wall so water is gained by osmosis.

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18
Q

What happens when plant cells loose a lot of water?

A

Plasmolysis - the inside contracts

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19
Q

What are xylem and what do they do?

A

They are made of dead plant cells and have a hollow lumen, thickened with a waterproof substance. They transport water and soluble minerals from the roots to the leaves.

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20
Q

What do phloem do?

A

They allows the movement of food/sugars (glucose) up and down stems to growing and storage tissues

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21
Q

How can the rate of transpiration be increased?

A

Light (increases photosynthesis), air movement (blows away water and gases), temperature (increases photosynthesis), low humidity.

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22
Q

How do leaves prevent water loss?

A

The stomata vary on different plants and their habitats and the turgidity of guard cells cahnges in relation to light intensity and water avaliability. During photosynthesis guard cells and turgid (open) but they become flaccid if there is a lack of water.

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23
Q

What do plants need nitrates for?

A

To make amino acids for proteins and cell growth. Lack of nitrates causes poor growth and yellow leaves

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24
Q

What do plants need potassium for?

A

Helping the enzymes in photosynthesis and respiration. Lack of potassium causes poor root and flower growth as well as discoloured leaves.

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25
What do plants need phosphates for?
To make DNA and cell membranes (respiration and cell growth). Lack of phosphates causes poor root growth and discoloured leaves.
26
What do plants need magnesium for?
To make chlorophyll for photosynthesis. Lack of magnesium causes yellow leaves.
27
What effects the rate of decay and why?
Temperature (enzymes), oxygen (more = more respiration, water (grow quickest in moist conditons)
28
What are detrivores? Give examples
Organisms that feed on dead organisms and decaying material (detritus) therefore speeding up the rate of decay because the particles have a larger surface area. Earthworms, woodlice and maggots
29
What are saphrophytes?
Fungi - they feed on dead organic material by secreting enzymes then absorbing the digested products
30
Why and how does battery farming improve productivity?
There is a better efficiency of energy transfer because there is less energy loss at each stage because of the warm conditons and limited movement
31
Give examples of intensive farming
Hydrophonics, fish farming, galss houses, battery farming
32
What are the advantages and disadvantages of organic farming?
Check in revision guide
33
What are the advantages and disadvantages of hydrophonics?
Check in revision guide
34
What are the advantages and disadvantages of biological control?
Check in revision guide
35
What is ossification?
When cartilage is replaced with calcium and phosphorous salts to make the bone hard
36
What is oesteoporosis?
A degenerative condition where the bones are weakened and break more easily
37
What are the different type of fractures?
Simple - cleanly breaks Greenstick - doesnt break completely Compound - when the bone breaks through muscle and skin
38
What is the differnce between ligament and tendons?
Ligments join bones together, tendons attatch bones to muscles
39
Label the anatgonistic muscles in the arm
Check in revision guide
40
Label the heart
Check in revision guide
41
Who were the two scientists that made discoveries about the heart?
Galeen, greek doctor: blood flows in tides between the liver and the heart William Harvey: the heart pumped through blood vessels, arteries and valves
42
What are the two pacemakers and what do they do?
Sinoatrial node SAN- atria contract Atrioventricular node AVN- ventricles contract They are groups of cells that produce electrical impulses to stimukate the heart muscle to contract
43
What is an echocardiogram and what is an electrocardiogram?
Echo/ECG - graph to show the pacemaker impulses in three different waves - P from SAN, R from AVN and T as the ventricles contract Electro - produces an uktrasound image of the beating heart
44
What is a bypass surgery used for?
To replace blocked coronary arteries
45
What are heart assist devises used for?
To help patient's muscles after a heart attack
46
What are the advantages and disadvantages of repairing the heart (pacemakers and artificial valves)?
``` Advantages: Less rejection risk No human donor Shorter waiting time Less traumatic surgery Disadvantages: Must take anticoagulants May need replacing ```
47
What are the advantages and disadvantages of replacing the heart (heart transplant)?
``` Advantages: Lasts a lifetime Patient can lead a full life Immediate effects Disadvantages: Long waiting list Major operation and expensive Need to take immunosuppressants ```
48
What are the intercostal muscles?
The muscles in between the ribs that raise and lower them
49
What is pleural membrane?
It protects and lubricates the lung surface
50
What are the three measurement of Kung capacity?
Tidal air: volume of air breathed in a normal breath Vital capacity air: Maximum volume of air that can be used for gas exchange Residual air: the air that stays in the lungs when you breathe out
51
What enzyme is in the mouth and what does it break down?
Carbohydrase (I.e. Amylase) - starch into sugars
52
What enzymes are in the small intestine and what do they break down?
Carbohydrase - starch into sugars Protease - proteins into amino acids Lipase - fats into fatty acids and glycerol
53
What enzyme is in the stomach and what does it break down?
Protease - proteins into amino acids
54
Describe how carbohydrase breaks down starch
Starch —> Maltose (double sugar) —> Glucose (single sugar)
55
What is egestion?
Getting rid of solid waste
56
What is excretion?
Getting rid pf waste products such as carbon dioxide, urea and sweat
57
What is the difference between the renal artery and the renal vein?
The renal artery carries dirty blood into the kidneys where it is filtered in the nephrons and then it travels out in the renal vein
58
What are the three stages that take place in the nephrons?
Ultrafiltration (glomerulus), selective reabsorbtion (tubules and capillaries), salt and water regulation (loop of Henlé)
59
What do FSH and oestrogen do?
FSH- Egg ripens stimulates oestrogen release | Oestrogen- stimulates lining of uterus to thicken, reduces FSH release (neg feedback) and stimulates LH release
60
What do LH and progesterone do?
LH- Controls ovulation (egg is released) | Progesterone- Preserves uterus lining
61
What do LH and FSH stand for?
LH- Luteinising hormone | FSH- Follice stimulating hormone
62
How do hormonal contraceptives work?
By micking pregnancy and inhibiting FSH release
63
What are fertility drugs?
FSH is injected into women who dont produce enough naturally
64
What is artificial insemination?
Sperm is placed directly into the uterus
65
What is IVF and what does it stand for?
In vitro fertilisation- sperm and eggs and combined outside of the body and the embryos are implanted into the uterus
66
What are the ways of treating fertilisation?
``` Fertility durgs IVF Artifical insemination Egg donation Surrogacy Ovary transplant ```
67
What could be the causes of infertility?
Blocked fallopian tubes or sperm ducts Egg not developing or being released Insufficient fertile sperm produced
68
What does ultrasound reveal in pregnancy?
Multiple pregnancies, developmental problems, the baby's sex
69
What does aminocentesis do and why is it controversial?
It samples the amniotic fluid from the amniotic sack | 1 in 200 babies die from it
70
What is foetal screening and why do some people think it is wrong?
It is a way of testing the health of a foetus (aminocentesis and ultrasound) some people think it offers the unacceptable option of ending an unborn baby's life
71
What are the problems with organ donation?
Ethical issues, religous beliefs, passing on diseases, must take immunosuppresants which reduce the immune system's ability to fight off other infections, not enough donors
72
What are the types of bacteria?
Spherical, spiral, curved rod, rod
73
How do bacteria reproduce?
Asexually, splitting in two (binary fission)
74
How does yeast reproduce?
Asexually by budding
75
How does temperature effect yeast growth?
It doubles with every 10°c rise but slows down at 40°c because the enzymes are denatured
76
Who developed the germ theory of disease?
Louis Pasteur- he showed that microorganisms where the cause of food decay
77
Who developed the first antiseptic?
Lister, a surgeon who realised spraying wounds with carbolic acid prevents wound infection
78
Who invented the first antibiotic?
Flemming- Penicillin, his bacteria culture plates got contaminated with penicillum mould
79
How do you make yoghurt?
Sterilise equipment (large steel fermenters) Pasteurisation - 80°c Add live bacteria culture, incubate (warm) Lactobacillus bacteria reproduce and feed on lactic sugars to make lactic acid Sampled and packaged
80
What is fermentation?
Anaerobic resoiration of yeast C6H12O6 -> 2C2H5OH + 2CO2 Glucose -> ethanol + carbon dioxide
81
How do you brew beer?
Allow barley seeds to sprout to turn starch into sugars then extract sugars Add hops for flavour Add yeast to ferment the mixture (kept warm so yeast respires and reproduces) Seal the tank - prevents microorganisms and aerobic respiration Add chemical so yeast settles to the bottom - clarifying Pasteurised 72°c 15 seconds
82
How do you distill spirits?
Liquid is heated to evapurate alcohol, concentrated alcohol is trapped and cooled (condensed)
83
What are three example of biomass fuels?
Manure broken down by bacteria or yeast, sugar cane broken down by yeast, fast growing trees burned
84
What is biogas?
The waste gas that bacteria produce when they feed on dead plant and animal material - Methane (over 10%) - Carbon diocide - Hydrogen sulphide - Hydrogen and nitrogen
85
How is biogas made?
Using a continuous flow method in a digester: waste in, sludge out, biogas trapped benath a metal gas holder and released using a tap Under 45°c
86
What can biogas be used for?
Burned to generate electricity, produce hot water and steam for central heating, fuel for buses and cars Useful in remote areas with no mains electricty
87
Why are landfill sites dangerous?
Because methane is produced as bacteria and other microbes feed on the rubbish and it is explosive
88
Why is biogas good for the environment?
Because it rpoduces no soot and doesnt increase greenhouse gas kevels as long as it is burned at the same rate as it is produced, areas of land arent cleared in order to grow vegetation for the fuel
89
What is gasohol and why is it used?
Alcohol mixed with petrol or diesel Be ause alcohol is cleaner but doesnt release as much energy and in places like brazil there are few oil reserves and lots of sugar cane
90
What is in soil?
``` Minerals Humus Organisms Water Oxygen ```
91
What four types of organisms does soil contain?
Herbivores, detrivores, decomposers and carnivores
92
Why are earthworms important?
They mix up the soil layers, they produce calcium carbonate to neutralise acidic soil, the aerate the soil, they drag down leave to be decomposed to release nutrient and charles darwin found that earthworms are important for soil fertility because they take the nutrients released by humus down into the soil to prevent it from being washed away
93
What are the two types of plankton and what do they do?
Phytoplankton- Microscopic plants Zooplankton- Microscopic animals Rely on currents, phytoplankton are the pridcuers
94
How can water become polluted?
``` Sewage Oil PCBs Fertilisers Pesticides Detergents ```
95
What is bioaccumulation?
The build up of chemicals such as PCBs (insulate electrical equipment) and DDT (pesticide) in the food chain so that large organisms die
96
How do amoeba face the problems of living in water?
The water in more dilute than its cytoplasm so water moves in by osmosis. It has lots of vacuoles which form a contracile vacuole to use active transport to pump water out of the cell
97
How is sucrose broken down?
Using sucrase or invertase Invertase: Sucrose —> glucose + fructose
98
Why are some people lactose intolerant?
Because they dont make lactase to break down lactic sugar. You can buy lactose free milk- lactase is added to break it down into glucose and galactose. If they do consume lactose it travels to their intestine where bacteria ferment the sugar.
99
How and why are enzymes immobilised?
Extracting and purifying enzymes is difficult so they are reused by immobilising them so they can be used in contiuous flow processing. You can put them in alginate jelly beads or out them on reagant sticks
100
How can you test for blood sugar?
The benedicts test- mixing blood or urine with benedicts reageant but a large sample is needed. The reagant turns red if sugar is present Reagant sticks make it easier
101
What ezymes are used in genetic engineering?
Restriction enzymes- cut open DNA leaving sticky ends | Ligase enzynes- Rejoin DNA strands using sticky ends
102
How do scientists identify transgenic organisms?
Assaying- genetically engineered bacteria are put on agar gel with antibiotics and only the genetically modified ones survive because they also add a marker gene like one that codes for antibiotic resistance
103
What are the four stages of DNA fingerprinting?
Extraction- DNA is removed from blood, hair etc. Fragmentation- DNA is cut into sections using restriction enzymes Separation- DNA sections are separated using electrophoresis (Electric field pulls fragments through gel, they distribute depending on their size, a radioactive probe is added and the film turns dark where there is radioactivity Visualising pattern- The barcode like patterns are compared with the suspects
104
What enxymes are used in biological washing powders?
Lipase- fats, amylase- carbohydrates, protease- proteins They work best at low temperatures or else the enzymes are denatured and very acidic or alkaline tap waters denature the enzymes

Biology B4-6 (4 decks)

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