Download The F2 ratio would be predicted as 3 Tall : 1 dwarf

Credit biosphere objectives
Errors made using the sampling technique of a quadrat
Identifying the organisms wrongly – minimise this error by
using a biological key
Only using it once will not give a reliable result – minimise error
by repeating it several times
Errors made using the sampling technique of a pitfall trap
Identifying the organisms wrongly – minimise this error by
using a biological key
Not checking it often enough as some organisms could get eaten
– minimise this by checking frequently
Errors that could be made using the measuring technique call a
light meter
People blocking the light – minimise this by moving them
Only taking one reading – minimise this error by repeating the
technique to give you a more reliable result
Errors that could be made using the measuring technique call a
moisture meter
Probe not clean before use – minimise this error by cleaning
probe before you use it to prevent contamination
Only taking one reading – minimise this error by repeating the
technique to give you a more reliable result
The abiotic factors that could influence where an organism
lives could be
Intensity of light – some plants like a lot of light and others
prefer to be in the shade
Level of moisture – Could be more moisture at the bottom of a
hill compared to the top and some plants prefer more moisture
so live at the bottom and others prefer less moisture so live at
the top
How it works
Explain the effect of removing one species from the food chain
The organism could decrease if its predator numbers increase
or it has less food to eat
The organism could increase if its predators decrease or it gets
more food to eat as less competition for food.
Pyramid of numbers represents the number of organisms at
each successive levels in a food chain
Pyramid of biomass represents the mass of organisms at each
successive levels in a food chain
Growth curve under ideal conditions will keep increasing
Nitrogen cycle
Plants take in nitrates from the soil to give them a supply of
nitrogen to make their proteins
This protein can be passed up to the consumers (animals) in a
food chain
When the plant or animal dies or pass out waste microorganisms help recycle the nitrogen
Dead organisms or waste decomposed by bacteria and fungi and
this passes out ammonia
Ammonia eaten by bacteria and pass out nitrite --- nitrification
Nitrite eaten by different bacteria and they pass out nitrate
which can now be taken in by the plants – back to the start
decomposition
Waste/
dead organisms
nitrification
ammonia
nitrification
nitrite
nitrate
Nitrogen cycle using nitrogen gas
Nitrogen gas can be taken in by nitrogen fixing bacteria in the
soil and they will pass out nitrates
Nitrogen gas
nitrogen fixation
nitrates
Lightning flash can also change nitrogen gas in atmosphere into
nitrates which will end up in the soil
Nitrates can be changed back into nitrogen gas by denitrifying
bacteria in the soil --- plants do not like this as they want the
nitrogen
dentrification by bacteria
nitrates
nitrogen gas
Leguminous plants – the lucky ones
They have nodules on their roots which house their own
nitrogen fixing bacteria and this gives them their own personal
supply of nitrates
Control and management
Adverse effects of using fossil fuels in power plants
Gives off CO2 gas which increases the greenhouse affect and
acid rain
Gives off SO2 gas which increases acid rain
Adverse effects of using nuclear fuel in power plants
Produces radioactive waste which could cause cancers
Relationship between level of organic waste in the water and
the number of micro-organisms
As the organic waste increases the number of micro-organisms
increases
Relationship between the number of micro-organisms and the
oxygen concentration
As the number of micro-organisms increases the oxygen
concentration decreases
Relationship between the oxygen concentration and the number
of species
As the oxygen concentration decreases the number of species
in the water decrease
Indicator species
An organism that indicates the level of pollution by their
presence or absence
Lots of lichens growing indicates a low level of SO2 pollution in
the air
Very few lichens growing indicates a high level of pollution
Controlling components of an ecosystem to grow plants eg trees
Habitat- the soil can be controlled by adding fertiliser
Animals – eat our crop so control them using pesticides
Plants – compete with our crop so control them with herbicides
Investigating Living Cells
Booklet 1 has no credit objectives
Booklet 2 Investigating Diffusion
Explain the importance of diffusion to organisms.
This allows the organism to gas exchange
Explain osmosis in terms of a selectively permeable membrane and of a
concentration gradient.
Water moving from a higher water concentration to a lower water concentration
passing through a selectively permeable membrane
Explain the osmotic effects in plants and in animal cells in terms of the
concentration of the water in the solutions involved.
Plants cells surrounded by a solution with a higher water concentration will take in
water by osmosis and become TURGID
Animal cells surrounded by a solution with a higher water concentration will take
in water by osmosis and BURST (no cell wall to protect it)
Plants cells surrounded by a solution with a lower water concentration will lose
water by osmosis and become PLASMOLYSED
Animal cells surrounded by a solution with a lower water concentration will lose
water by osmosis and become SHRIVELLED UP
Booklet 3 Investigating Cell Division
Describe the stages of mitosis
Each chromosome becomes two chromatids
Chromosomes line up at the equator
Spindles pull the chromatids apart
Cytoplasm divides and becomes two daughter cells
Explain why it is important that the chromosome complement of daughter cells in
multicellular organisms is maintained.
So that each cell has all the information to develop and function correctly
Booklet 4 Investigating enzymes
Explain the term specific as applied to enzymes and their substrate.
Each enzyme has an active site (mouth) which only one substrate can fit into and
no other.
Degradation enzymes (speed up the breakdown of the substrate)
Amylase enzyme – only starch fits into the active site
Lipase enzyme- only Fats (lipids) fit into the active site
Catalase enzyme – only hydrogen peroxide fits into the active site
Pepsin enzyme – only protein fits into the active site
Synthesis enzyme – (speed up the build up of new bigger substances)
Phosphorylase enzyme – only Glucose –1-phosphate fits into the active site
Explain the term optimum as applied to the range of conditions in which enzymes
operate
Optimum means the condition which the enzyme is most active.
Enzymes in a range of temperature
0 - 40oC
enzymes activity increases
40oC and above enzyme activity decreases
Above 50oC the enzyme becomes denatured
Enzymes in a range of pH – depends on enzyme
Pepsin – active over a range of pH 1-7 optimum at pH of 2
Amylase – active over a range of pH 4 – 9 optimum of pH 7
Catalase – active over a range of pH 7-14 optimum at pH 12
Booklet 5 Investigating aerobic respiration
State that oils contains more chemical energy per gram than carbohydrates or
protein.
Burning food experiment can prove this.
Valid experiment (validity)
Variable changed – type of food
Variables kept constant – volume of water , mass of food and distance between
burning food and water
To make Results more Reliable – Repeat experiment
Explain the importance of energy released from food during respiration to the
metabolism of cells.
Energy needed to allow all the chemical reaction to occur.
Animal Survival
The elements in carbohydrates
Carbon Hydrogen and oxygen
The elements in Fats (lipids)
Carbon Hydrogen and oxygen
The elements in Protein
Carbon Hydrogen and oxygen and Nitrogen
Carbohydrates are made of
Glucose molecules
Fats are made of
Fatty acids and glycerol
Proteins are made of
Amino acids
Digestion means
The breakdown of insoluble foods into soluble foods
Digestive juices are produced in the
Salivary glands
Stomach wall
Pancreas
Small intestine
Liver
Peristalsis
The muscles behind the food contract and the muscles in front of the
food relax
Explain how the contraction of the stomach help the chemical
breakdown of food.
It mixes the food with the gastric juice ( pepsin and HCL acid)
An amylase enzyme
Salivary amylase starch
A protease enzyme
Pepsin
Protein
A lipase enzyme
Pancreatic lipase fats
maltose SAM
amino acids
fatty acids and glycerol FLAG
A Villus - Many folds in the small intestine
Thin epithelium
Quick diffusion of digested food
Blood capillary
Transports absorbed glucose and amino acids
Lacteal
Transports absorbed fatty acids and glycerol
Reproduction
Explain the importance of internal fertilisation to land living animals
The female body will always have liquid for the sperm to swim in
Explain the relationship between the number of eggs / young produced
and parental protection during fertilisation and development in fish and
mammals
The lower the number of eggs produced means that there is a higher
degree of parental protection eg human females only produce one egg
at a time which shows there is a very high degree of parental
protection
Describe the structure and function of the placenta
Function – to exchange substances between the embryo and mother
Structure
Many folds – increase the surface area to allow more substances to
exchanged
Large blood supply – to transport the substances
Thin – quick diffusion of substances
Water and waste
Explain the role of ADH in the regulation of water balance
If the blood has a decrease in the water concentration then
the pituitary gland will increase the production of ADH
This will increase the permeability of the nephron tubule to water
More water will be reabsorbed
Urine volume decreases but the
Urine concentration increases
State the source of urea
Urea is made in the liver
How is urea transported to the kidney
In the renal artery
Artificial kidney (dialysis)
Benefits – person stays alive
Limitations – they have to be on the machine for several hours 3 times
a week
- must control what they eat when they are not on the machine
Replacement kidney (transplant)
Benefits – lead a fairly normal lifestyle
Limitations – kidney can be rejected
Responding to the environment
Why do woodlice move more in dry conditions (stimulus)
As they are trying to find a moist area so they do not dry up
Why do woodlice move more in light areas
As they are trying to find a dark area to hide from predators
Rhythmical behaviour - follows a repeated pattern
Hibernation or migration – stimulus is the decreasing length of daylight
Significance – survives the winter when there is less food
Nocturnal owl – stimulus is the onset of darkness
Significance – will be active when their food is around
Nocturnal mice – stimulus the onset of darkness
Significance – will be active when they are better hidden from
predators
World Of Plants Credit objectives
Introducing plants - Part 1
Explain the consequences to man and other animals of a reduction in the
variety of species.
Man - Less food / Less medicines / less raw materials
Other animals - Fewer habitats to live in / less food to eat
Describe a production or refining process
Production of timber - grow trees in a nursery and then plants out on
the hillside. If fertilisers need to be added to soil use a helicopter or
plane. Cut some of the trees down (fell them) to reduce competition
every 5 years. Finally cut all the trees down after 50 years.
Use timber for building / paper etc
Describe two potential uses of plants.
New medicines or new food sources
Growing plants - part 2
Describe the percentage germination that occur over a range of
temperatures.
0 to 40 oC - percentage germination increases
40oC and above - percentage germination decreases
Explain the structure of wind pollinated flowers in relation to sexual
reproduction.
Anthers outside flower to put the pollen in the wind
Feathery stamens hang outside to catch the pollen in the wind
Explain the structure of insect pollinated flowers in relation to sexual
reproduction.
Anthers inside the flower to put the pollen onto the insect when it
comes into the flower.
Stigma inside the flower to collect the pollen from the insect when it
comes into the flower.
Nectary gland produces nectar to attract the insect into the flower
Describe the growth of the pollen tube and fusion of gametes
The pollen lands on the stigma and grows a pollen tube.
The male sex cell nucleus travels down the pollen tube and enters the
ovule and fertilises the female nucleus.
Describe fruits that use wind as a method of seed dispersal.
The fruits have wings or fluffy parachutes to fly in the wind
Describe fruits that use animal internal as a method of seed dispersal.
The fruits are edible ( can be eaten and seed passes through the
animal)
Describe fruits that use animal external as a method of seed dispersal.
The fruits have hooks to catch onto the outside of the animal
Explain the advantage to humans of artificial propagation in flowering
plants
The plants with desired characteristic are produced (clones)
A lot of the desired plant is quickly produced.
Describe the term clone.
A clone is genetically identical offspring to the parent.
Describe the advantages of sexual reproduction to plants.
Increases variation which increases the chances of survival if the
environment should change
Fruits can disperse the seeds which will allow the plant to colonise new
areas
Describe the advantages of asexual reproduction to plants.
Quickly produces lots of plants, which cover the area and reduce
competition with other plants.
Does not involve all the stages of sexual reproduction so more chance
to survive.
Making food - part 3
Describe the structure of phloem.
Have sieve cells with sieve plates and companion cells.
State the function of phloem
Transports food
Describe the structure of xylem
Long, hollow tubes with lignin
State the 2 functions of the xylem vessels
Transport water and minerals + support for the plant
Describe features of the leaf that allow it to be efficient at gas
exhange
Thin - quick diffusion of gases
Lower epidermis has stomata, which allow gas exchange between leaf
and atmosphere. These are controlled by guard cells.
Spongy mesophyll - these cells have circular shape to allow quicker
diffusion of CO2 to the palisade mesophyll cells above
Veins on the leaf - these are the vascular bundles that contain the
xylem and phloem
Describe the fate of CO2 as structural and storage carbohydrates in
plants and as an energy source.
CO2 will end up in the glucose made during photosynthesis and this can
be glucose can be used for respiration ( providing energy)
This glucose can then be changed into a storage carbohydrate called
starch
The glucose can also be changed into a structural carbohydrate called
cellulose.
Explain what is meant by a limiting factor.
This is something that is in short supply to the plant and if increased
will increase the rate of photosynthesis.
State the 3 main limiting factors in photosynthesis.
Light intensity
CO2 concentration
Temperature
Remember the rule if using a graph to find a limiting factor If the graph is rising the limiting factor is on the X axis (look down)
If the graph is level then it is not the factor on the X axis so you have
to look up to the graph above
Inheritance Credit objectives
Part 1
Explain what is meant by discontinuous variation
It is a variation that falls into 2 or more distinct groups
Explain what is meant by continuous variation
It is a variation that falls within a range of values
Part 2
State that the parents in experimental monohybrid crosses are usually
true breeding and show different phenotypes of the same
characteristics.
Example of this would be - Tall plants (TT) crossed with dwarf
plants(tt)
TT X
tt
Predict the proportions of the phenotypes of the F2 offspring of a
monohybrid cross
The parents would be Tt (Tall) X Tt (Tall)
The F2 ratio would be predicted as 3 Tall : 1 dwarf
Know the definition of alleles.
Alleles are different forms of a gene
Explain the differences between observed and predicted figures in a
monohybrid cross.
This is due to the fact that fertilisation is a random process.
Part 3
Describe one animal example of the enhancement of a characteristic
through selective breeding.
Cattle -- enhanced milk yield OR enhanced meat production
Describe one plant example of the enhancement of a characteristic
through selective breeding.
Sunflower plant -- enhanced oil production
Give an example of a chromosome mutation, advantageous to humans.
Polyploid plants are caused by a chromosome mutation and have
increased yield of crop and are bigger and stronger than the normal
plants
Give an example of a factor which can influence the mutation rate in an
organism.
X rays / UV light / certain chemicals eg mustard gas
Biotechnology Credit objectives
Describe the process of anaerobic respiration in yeast cells.
Sugar
energy + CO2 + alcohol
Compare anaerobic respiration with aerobic respiration in yeast cells.
Anaerobic respiration provides less energy and the by products are CO2
and alcohol instead of CO2 and water
Describe how the commercial brewers provide the best growing
conditions for yeast.
They provide the optimum temperature and pH for optimum enzyme
activity
Explain what is meant by batch processing
All ingredients are added at the start and the product is removed at
the end.
Explain the need for malting of barley before use by the brewing
industry.
The starch in the barley grain is changed into maltose sugar and the
yeast cells use this sugar.
Explain the souring of milk in terms of bacterial fermentation of
lactose.
The bacteria use the lactose sugar to provide them with energy and
pass out lactic acid, which makes the milk sour.
Explain the precautions, which are taken during the manufacturing
process with reference to resistant fungal and bacterial spores.
They have to use very high temperatures (121oC) or strong chemicals
Describe the part played by bacteria in the nitrogen cycle
Bacteria are involved in decomposition (waste to ammonia), nitrification
(ammonia to nitrite and then to nitrate). Also denitrification (nitrate
to nitrogen gas) and nitrogen fixation (nitrogen gas to nitrates)
Describe the part played by bacteria in the recycling of carbon.
Bacteria release the carbon as CO2 during decomposition of waste,
which can be taken in by the plants for photosynthesis.
Explain the process of decay in terms of the energy requirements of
micro-organisms
The micro-organisms use the waste as an source of energy
Explain why complete breakdown of sewage is only possible in aerobic
conditions.
Because oxygen is needed for the complete breakdown of sewage
Explain why a range of micro-organisms is needed to breakdown the
range of materials in sewage.
A range of micro-organisms are used to make sure all the material in
the sewage is completely broken down.
Explain the advantage of upgrading waste
Waste can be changed into either, a high protein food (whey into
cattle feed) or into a high energy fuel (manure into methane gas)
Explain genetic engineering in terms of manipulation of chromosomal
material.
Locate insulin gene and cut it out of the DNA.
Remove plasmid from bacterial cell and cut open
Add insulin gene to plasmid and replace into bacterial cell
Genetically engineered bacteria now multiply and produce insulin,
which can be purified
State that as a result of genetic engineering, bacteria can produce
large quantities of insulin very quickly
Learn the above statement
Why do we now need more insulin produced by biotechnology.
As there are more people with diabetes now
What are the two advantageous of producing new genotypes by genetic
engineering compared to selective breeding.
It is quicker and almost guaranteed to produce the new genotype
What are the two main advantages of using biological detergents
compared to non-biological?
Washing is at lower temperatures, which saves energy/money and
protects delicate material
Explain the action of biological detergents in terms of digestive
enzymes.
Biological detergent contains digestive enzymes, which were made by
genetically engineered bacteria. These enzymes breakdown the stains
on the clothes.
Describe the advantages of using immobilisation techniques.
The enzyme or yeast can be put into a jelly bead, which will be able to
be used over again and also be removed from the product.
Explain how continuous flow processing uses immobilisation and the
advantages this has over the batch processing.
Only continuous flow processing uses immobilization as it allows the
enzyme or yeast to be used many times and it will remain in the process
as the product is removed.
The body in Action Credit objectives
Movement
Describe the structure of a synovial joint and state the function of its
parts.
Cartilage ( at the end of the bones)
Acts as a shock absorber and reduces friction at the joint
Synovial fluid
Reduces friction at a joint
Synovial membrane
Produces synovial fluid
Ligament
Holds the bones in place at a joint
State that bone is formed by living cells.
Learn the above statement
Explain why tendons are inelastic.
So the pull of the muscle is transferred to the bone
Explain the need for opposing muscles at a joint
One muscle contracts to bend the limb and the other muscle contracts
to straighten the limb
The Need for Energy
Describe the mechanism of breathing in humans
To inhale -
intercostal and diaphragm muscles contract
this increases the volume and decreases the pressure
air moves into the lungs
To exhale -
intercostal and diaphragm muscles relax
this decreases the volume and increases the pressure
air is pushed out of the lungs
Explain the function of the mucus in trachea and bronchi tubes
This traps the dirt and germs in the inhaled air
Explain the function of the cilia in the trachea and bronchi tubes.
This pushes the mucus out of the lungs
Describe the gas exchange between the air sacs and the surrounding
blood vessels.
Oxygen diffuses from the air sacs to the blood and carbon dioxide
diffuses from the blood to the air sacs
Describe the features, which make the lungs efficient gas exchange
structures.
Large surface area; thin walled air sacs; good blood supply; always moist
Explain the function of haemoglobin in the red blood cells
This helps the red blood cells transport oxygen.
Describe the features of a capillary network, which allow efficient gas
exchange.
One cell thick; large surface area; come close to all the body cells
Co-ordination
Explain the relationship between judgement of distance and binocular
vision
Each eye sends a different image to the brain, which can then create a
3 dimensional picture to judge distances better.
Explain how the arrangement of semicircular canals is related to their
function
Each fluid filled canal is set at right angles to each other
This detects movement in all directions
Describe how a reflex action works, using a simple model of a reflex
arc.
State the central nervous system sorts out information from the
senses, and sends messages to those muscles to take the correct
response.
Learn the above statement
Know the function of the cerebrum in the brain.
For memory, reasoning, sight, sound
Know the function of the cerebellum in the brain.
For balance and co-ordination
Know the function of the medulla
Controls automatic actions eg breathing, heart beat.
Changing levels of performance
Explain muscle fatigue in terms of anaerobic respiration
Muscle cells have no oxygen so produce lactic acid instead of CO2 and
H2O
State that training improves the efficiency of the lungs circulation
Learn the above statement
Explain the relationship between the effects of training and recovery
time.
Training makes the lungs larger so more oxygen diffuses into the blood
and also the heart muscle is stronger and can push a greater volume of
blood each time