Biology Y10 Topics
Unit
Title
1
Characteristics and classification of living organisms
2
Organisation of the organism
3
Movement in and out of cells
4
Biological molecules
5
Enzymes
6
Plant nutrition
7
Human nutrition
8
Transport in plants
9
Transport in animals
10
Diseases and immunity
11
Gas exchange in humans
12
Respiration
To be classed as a “living organism” the subject must perform all 7 life processes.
Invertebrates
Feature
Number of
pairs of legs
Body regions
Number of
pairs of
antennae
Type of eyes
Wings
myriapods
crustaceans
insects
arachnids
Plant Classification
Flowering plants are called ANGIOSPERMS. They are multicellular organisms.
Their cells have cellulose cell walls made when glucose from photosynthesis
is converted to cellulose. Some contain chloroplasts, roots, stems and leaves.
They reproduce sexually and asexually and produce seeds and fruits. There
are two types; Monocotyledons and Dicotyledons
Parallel
two
broad
network
narrow
flowering
one
Monocotyledons are ___ plants that often have ___ leaves with
___ veins. They have ___ cotyledon inside the seed. Dicotyledons
often have ___ leaves with a ___ of veins. They have ___
cotyledons inside each seed.
1) Define the term growth and sensitivity. (Grade D)
2) Describe why scientists use the binomial naming system for naming new species of organisms.
(Grade D)
3) Produce a dichotomous key to separate the following species: Lion, Tiger, Cheetah, Jaguar, Snow
leopard. (Grade A)
4) Identify three differences between monocotyledon plants and dicotyledonous plants. (Drade D)
5) Explain why a leaf is classed as an organ and not a tissue. (Grade C)
6) Explain why are virus not accepted to be “living organsims” under the rules of the 7 life
processes? (Grade C)
Structure
Description
Organelle
Cell structure that is specialised to
carry out a particular function or job
Cell
Basic structural and functional unit
of a living organism
Tissue
Group of cells with similar
structures, working together to
perform a shared function
Organ
Structure made up of a group of
tissues, working together to perform
specific functions
Organ system
Group of organs with related
functions, working together to
perform body functions
You need to know that all cells
(except some prokaryotes) contain
things called ribosomes, rough
endoplasmic reticulum and
mitochondria.
Mitochondria is where respiration
takes place and ALL cells have
them! Cells that need more energy
like muscles and sperm cells
contain more mitochondria.
1) Write down the calculation for calculating the magnification of a cell. (Grade C)
2) Explain how the vacuole and the cell wall help to maintain the plant cells structure (Grade B)
3) Analyse how the red blood cell is adapted to its function. (Grade B)
4) Explain how you would prepare a slide to view under a microscope. (Grade A)
5) Illustrate an animal cell and a plant cell (Include labels) (Grace B)
•
•
•
Define diffusion as the net movement of particles through a semi-permeable
membrane from a region of their higher concentration to a region of their lower
concentration down a concentration gradient, as a result of their random movement.
Define osmosis as the movement of water molecules from an area of high water
potential to an area of low water potential, through a semi permeable membrane.
Define active transport as the movement of molecules from an area of low
concentration to an area of high concentration through a semi permeable membrane.
This requires a carrier protein and the input of energy.
Isotonic solution: A solution
of equal concentration to cell.
Hypotonic solution:A solution
of lower concentration of
salts compared to cell. (High
water potential)
Hypertonic solution: A
solution containing a higher
concentration of salts
compared to cell (Low water
potential)
Osmosis Demonstration
explanation
When the funnel is placed into the
beaker, it forms a concentration
gradient between the distilled
water in the beaker and the
solution in the funnel. The funnel
contain 3% salt, which lowers its
water potential, in comparison to
the distilled water. This causes the
water molecules to pass through
the semi permeable membrane
from an area of high water
potential to an area of low water
potential.
The water pressure inside plant cells is
called turgor pressure, and it is
maintained by a process called osmosis.
Technically speaking, osmosis is the
movement of water across a
differentially permeable membrane
from a place where water concentration
is higher to one where the
concentration is lower.
When transporting organs. The
organ is placed in an isotonic
solution. If it was put in a hypo or
hypertonic solution the organ
could be permanently damaged.
Plants need to absorb
mineral ions from the soil.
This includes, phosphates,
nitrates and magnesium
ions.
Active transport is used in two
parts of the human body. The
section of small intestine called
the ILEUM contains villi which
actively reabsorb glucose.
The kidney also actively
reabsorbs glucose to prevent
glucose needed for energy being
mixed with urine and excreted!
1) Define the term diffusion. (Grade D)
2) Describe where in animals and plants you can find examples of diffusion.(Grade C)
3) Explain how active transport is used to absorb minerals into root hair cells (Grade C)
4) Create a table comparing the similarities and differences between osmosis, active transport and
diffusion. (Grade A)
5) Illustrate an experiment that can be used to teach year 9 students about osmosis. Provide an
explanation of what happens during the experiment. (Grade A)
Biochemical tests can be used to identify different substances found
in our food.
To test for starch a few drops of iodine solution are added to the unknown substance. If starch is present the
iodine will turn from an orange colour to a deep blue black.
To test for protein a few drops of biuret regent are added to the unknown substance. If the substance contains
protein the biuret solution will turn from blue to purple.
To test for glucose (or other reducing sugars) a few drops of benedict's solution are added to the unknown
substance. The solution then needs to be heated for a few minutes in boiling hot water. If glucose is present, the
benedict's solution will turn from blue to brick red.
Testing for vitamin C using DCPIP. Vitamin C takes the colour out of a blue dye called DCPIP. The number of
drops of vitamin C solution needed to make this happen depends on the concentration of vitamin C in the
solution. Thus, the more drops needed to turn the DCPIP to clear, the lower the concentration of vitamin C in
the solution.
Testing for lipids : Emulsion test
2 to 4 ml of ethanol is added to
the unknown solution. This is
gently stirred together. The
mixture is then poured into a test
tube containing an equal volume
of distilled water. If lipids are
present, a milk white emulsion is
formed.
Hydrolysis: The process of breaking down large molecules into
smaller ones by the addition of water. This is how enzymes work.
Condensation: The joining of small molecules to make larger
molecules by removing water.
Soluble: A solid which can dissolve into a liquid.
Insoluble: A solid which cannot dissolve into a liquid.
1) Define the term Organic molecule. Grade D)
2) Explain what hydrolysis and condensation are. (Grade C)
3) Explain what the terms soluble and insoluble mean. (Grade C)
4) If you did all four biochemical tests on an unknown solution, and the solution contained glucose, protein and
lipids, what would the results table look like. Illustrate the results table below. (Grade B)
5) Create a method for carrying out an emulsion test. Include two heath and safety aspects. (Grade A)
Enzymes are biological catalysts. This means they are able to speed up
chemical reactions by breaking down substrates into smaller molecules.
Enzymes are substrate specific, this means that each type of enzymes only
works of a specific substrate. E.g Amylase and starch. The lock and key model
is a good method of demonstrating how enzymes function.
All enzymes are different, and each
has its preferred conditions where
it is able to work at its optimum.
Factors affecting the rate of enzyme
reaction include: Temperature, pH,
and concentration of enzymes.
Denature
Enzymes can denature if they are
placed in too high temperatures.
The high temperature causes the
enzyme to twist and alter shape.
This changes the shape of the active
site, preventing it from working on
the substrate.
Amylase Starch into maltose
Lipase  Fats
Pepsin  Protein
Trypsin  Protein
Maltase  Maltose to glucose
Hydrogen peroxide (H2O2) is a by-product of respiration and
is made in all living cells. Hydrogen peroxide is harmful and
must be removed as soon as it is produced in the cell. Cells
make the enzyme catalase to remove hydrogen peroxide.
This investigation looks at the rate of oxygen production by
the catalase in pureed potato as the concentration of
hydrogen peroxide varies. The oxygen produced in 30
seconds is collected over water. Then the rate of reaction is
calculated.
1) Give an explanation of what an enzymes function is.(Grade C)
2) Using a diagram, illustrate why enzymes are classed as substrate specific (Grade B)
3) List 3 Enzymes with their substrate and the products they form.(Grade C)
4) Describe how an increase temperature from 0 degrees to 100 degrees affects an enzyme of your choise.
(Grade A)
5) Create a method which can be used to find out the optimum pH of an enzyme of your choice. (ensure you
identify the different variables in your experiment) (Grade A)
Photosynthesis is a chemical reaction which
happens inside pant cells. It uses carbon
dioxide, water, and the sun’s energy to form
glucose (chemical energy) and oxygen.
This primarily happens in palisade cells which
can be found in the upper layer of the leaf.
These cells are packed with chloroplast, so that
they can do a high amount of photosynthesis.
Each chloroplast contains chlorophyll, which is
the essential pigment required for absorbing
the suns light energy.
Factors effecting the rate
of photosynthesis:
Levels of carbon dioxide
and water.
Light levels/intensity
Environmental
temperature.
There are two method of proving whether or not photosynthesis is taking place. Firstly, we can use
iodine solution to test whether or not the plant is producing starch (This is the stored version of
glucose). Alternatively, we can use hydrocarbonate indicator to see whether the plant is taking carbon
dioxide out of the environment and using it for photosynthesis.
Testing the rate of photosynthesis
We can measure the rate of
photosynthesis by analysing the
amount of oxygen produced. This
can either be done by counting the
number of bubbles given off by a
piece of pond weed, or by
collecting those bubbles in a
measuring cylinder and measuring
the amount of oxygen produced in
a given time period.
1) Define the term photosynthesis and give a word equation for the chemical reaction (Grade C)
2) Explain how light intensity affects the rate of photosynthesis. (Grade C)
3) Analyse how oxygen and carbon dioxide are supplied and removed for photosynthesis. (Grade B)
4) Design an experiment which can be used to find out how temperature affects the rate of photosynthesis.
(Ensure you identify each of the variabes) (Grade A)
Peristalsis
Food is moved through the digestive system by a process called peristalsis.
Two sets of muscles in the gut wall are involved:
circular muscles - which reduce the diameter of the gut when they contract
longitudinal muscles - which reduce the length of the gut when they contract
The muscles work together to produce wave-like contractions. These have a
‘squeezing action’ that pushes the bolus through the gut.
Bile is secreted into the small intestine where it has two effects:
it neutralises the acid - providing the alkaline conditions needed
in the small intestine
it emulsifies fats - providing a larger surface area over which the
lipase enzymes can work
The villi (one is called a villus) are tiny, finger-shaped
structures that increase the surface area. They have several
important features:
wall just one cell thick - ensures that there is only a short
distance for absorption to happen by diffusion and active
transport network of blood capillaries - transports glucose
and amino acids away from the small intestine in the blood
internal structure called a lacteal - transports fatty acids and
glycerol away from the small intestine in the lymph
1) Define the following key words:Ingestion, peristalsis, digestion, assimilation,alimentary canal.(Grade
D)
2) Explain the difference between mechanical digestion and chemical digestion. (Grade C)
3) Explain the purpose of emulsification, and how it is done. (Grade B)
4) Analyse how the small intestine is adapted to its function. Incl. information regarding surface areas,
blood supply, villi, and intestinal wall thickness. (Grade A)
5) List 5 organs in the digestive system and explain the function of each organ. (Grade C)
Transpiration
Transpiration explains how water moves up the plant against gravity in tubes made of dead xylem cells
without the use of a pump.
Water on the surface of spongy and palisade cells (inside the leaf) evaporates and then diffuses out of the
leaf. This is called transpiration. More water is drawn out of the xylem cells inside the leaf to replace what's
lost. As the xylem cells make a continuous tube from the leaf, down the stem to the roots, this acts like a
drinking straw, producing a flow of water and dissolved minerals from roots to leaves.
Factors that speed up transpiration will also increase the rate of water uptake from the soil. When water is
scarce, or the roots are damaged, it increases a plant’s chance of survival if the transpiration rate can be
slowed down. Plants can do this themselves by wilting, or it can be done artificially, like removing some of
the leaves from cuttings before they have chance to grow new roots.
Factor
Description
In bright light transpiration
increases
Explanation
The stomata (openings in the leaf) open wider to allow
more carbon dioxide into the leaf for photosynthesis
Temperature
Transpiration is faster in higher
temperatures
Evaporation and diffusion are faster at higher
temperatures
Wind
Transpiration is faster in windy
conditions
Humidity
Transpiration is slower in humid
conditions
Light
Water vapour is removed quickly by air movement,
speeding up diffusion of more water vapour out of the
leaf
Diffusion of water vapour out of the leaf slows down if
the leaf is already surrounded by moist air
Transpiration and water loss from leaves happen because of the way
that leaves are adapted for efficient photosynthesis. The flat, thin
shape of a leaf, its spongy mesophyll layer and stomata are
adaptations that also allow water loss from the leaf. Features
involving the guard cells around the stomata provide a way to reduce
excessive water loss.
The size of the stomatal opening can be altered by the plant in
response to the availability of water and the light intensity. For
example, in conditions where there is plenty of water and bright light:
Chloroplasts make sugars at a high rate
Water enters the guard cells from other cells by osmosis
The guard cells become turgid
The stomatal opening gets bigger
Tissue
Process
Xylem
Transpiration
Phloem
Translocation
What is moved
Moves water and minerals from
roots to leaves
Moves food substances from
leaves to rest of plant
Structure
Columns of hollow,
dead reinforced cells
Columns of living
cells
1) Define the term transpiration. (Grade D)
2) Explain the process of transpiration, linking in osmosis to your explanation. (Grade C-A)
3) Discuss how each of the following factors affects the rate of transpiration: Humidity, temperature,
wind. (Grade A)
4) Create a summary table comparing transpiration with translocation. (Grade B)
5) Design an experiment which can be used to test the rate of transpiration and explain how it works.
(Grade A)
The passage of blood through the heart
Deoxygenated blood arrives at the left-hand side of the heart:
1.It enters the heart through the vena cava.
2.Blood flows into the right atrium.
3.Blood is pumped into the right ventricle.
4.Blood is pumped out of the heart, along the pulmonary
artery, to the lungs.
Oxygenated blood arrives at the right-hand side of the heart:
1.It enters the heart through the pulmonary vein.
2.Blood flows into the left atrium.
3.Blood is pumped into the left ventricle.
4.Blood is pumped out of the heart, along the aorta, to the
rest of the body.
Capillaries are the smallest type of blood vessel, and are adapted
to allow the effective exchange of substances between the blood
and the tissues of the body. Capillaries intermingle with the
tissues and exchange nutrients, gases, and wastes
Capillaries
Capillaries are made of thin cells, meaning that some parts of the
blood can easily leave the capillary, bathing the cells in a fluid
known as tissue fluid.
Useful substances within the tissue fluid - including glucose,
oxygen and amino acids - can then diffuse into the cells down a
concentration gradient. The concentration gradient is always
maintained as the useful substances are constantly being used
up by the cell.
Waste substances generated by the cell diffuse out of the cell,
and back into the tissue fluid. Most of the tissue fluid is then
reabsorbed back into the blood, and with it the waste substances
– such as carbon dioxide and urea – which are taken away to be
excreted.
A concentration gradient is always maintained as the cell
constantly generates more waste substances, and the blood
constantly takes them away.
1) Describe the function of each component of the blood. (Grade D)
2) Illustrate each blood vessel and explain its adaptations. (Grade C)
3) Explain what coronary heart disease is and analyse different methods of treating or preventing the
disease. (Grade B)
4) Analyse the function of the lymphatic system. (Grade C)
White blood cells
Pathogens contain certain chemicals that are foreign to the body, called antigens.
White blood cells - lymphocytes - carry antibodies - proteins that have a chemical 'fit'
to a certain antigen. When a white blood cell with the appropriate antibody meets
the antigen, it reproduces quickly and makes many copies of the antibody that
neutralises the pathogen. Alternatively, phagocytes are able to engulf pathogens and
produce antitoxins.
Immunisation
People can be immunised against a pathogen through vaccination. Different
vaccines are needed for different pathogens. Vaccination involves putting a small
amount of an inactive form of a pathogen, or dead pathogen, into the body.
Vaccines can contain:
•
•
•
•
live pathogens treated to make them harmless
harmless fragments of the pathogen
toxins produced by pathogens
dead pathogens
These all contain different proteins called antigens. When injected into the body,
they stimulate white blood cells to produce antibodies against the pathogen. The
body also produces memory cells which remember what the pathogen was for a
more rapid immune response if infected again.
Memory cells
Memory cells are a type of white blood cell (lymphocyte) that can respond quickly
when it meets a microorganism for the second time. They produce the right antibody
for the particular microorganism and destroy it before you feel unwell. This is
described as being immune to a disease.
Antibiotic resistance
Over time, bacteria can become resistant to certain antibiotics. MRSA is methicillinresistant Staphylococcus aureus. It is very dangerous because it is resistant to most
antibiotics. To slow down or stop the development of other strains of resistant
bacteria, we should:
avoid the unnecessary use of antibiotics
always complete the full course
1) Describe passive immunity and active immunity.
2) Illustrate a bacteria cell, virus cell, and a fungi cell; include labels. (Grade C)
3) Analyse the body’s response for when a pathogen enters the body. (Grade B)
4) Compare vaccinations against antibiotics and evaluate the advantages and disadvantages of each
method of fighting pathogens. (Grade A)
5) Explain what memory cells are. (Grade C)
Ventilation
The ribs, intercostal muscles and diaphragm all play important
roles in ventilation (breathing).
Breathing in
When you inhale:
1.the internal intercostal muscles relax and the external
intercostal muscles contract, pulling the ribcage upwards and
outwards
2.the diaphragm contracts, pulling downwards
3.lung volume increases and the air pressure inside decreases
4.air is pushed into the lungs
Breathing out
When you exhale:
1.the external intercostal muscles relax and the internal
intercostal muscles contract, pulling the ribcage downwards
and inwards
2.the diaphragm relaxes, moving back upwards
3.lung volume decreases and the air pressure inside increases
4.air is pushed out of the lungs
Inhaled air
Exhaled Air
Oxygen 21%
Oxygen 16%
Nitrogen 78%
Nitrogen 78%
Carbon dioxide
0.04%
Carbon dioxide
4%
Argon 1%
Argon 1%
Limewater turns milky in the
presence of carbon dioxide, so it
can be used to show the
differences between inhaled
(inspired) air and exhaled (expired)
air. The limewater immediately
turns milky on contact with exhaled
air.
Blood pH
The pH of the blood is normally 7.35 to 7.45 – a narrow range. During exercise, the concentration of carbon
dioxide in the blood and respiring tissues increases. This could lower the pH (making the blood more acidic).
To prevent this happening:
substances in blood plasma react with the excess carbon dioxide increases in the rate and depth of
breathing speed up the rate at which carbon dioxide is removed from the bloodstream
Within the lungs is a network of tubes through which air is able to pass. Air is firstly
warmed, moistened and filtered as it travels through the mouth and nasal passages.
It then passes through the trachea and down one of the two bronchi and into one of
the lungs.
After travelling into the many bronchioles, it finally passes into some of the millions
of tiny sacs called alveoli, which have the specialised surfaces for gas exchange.
Alveoli have several adaptations:
They are folded, providing a much
greater surface area for gas
exchange to occur.
The walls of the alveoli are only
one cell thick. This shortens the
diffusion distance which gases
have to move.
Each alveolus is surrounded by
blood capillaries This is important
as the blood is constantly taking
oxygen away and bringing in more
carbon dioxide - which helps to
maintain the maximum
concentration gradient.
1) Explain the pathway air takes from outside the body to inside the red blood cells. (Grade C)
2) Analyse the changes in chest cavity volume, and how these occur, when inhaling and exhaling. (Grade
B)
3) Evaluate the effects smoking can have on the respiratory system, with references to two respiratory
breathing diseases. (Emphysema, bronchitis.) (Grade A)
4) Compare the content of inhaled air with exhaled air, and explain why the amounts of each content
have changed. (Grade A)
5) Illustrate the respiratory system.
Aerobic respiration (Animals and plants)
Respiration is a chemical reaction which
happens inside the cells of living organisms. It
is used to release chemical energy stored in
food (glucose). There are two types of
respiration aerobic and anaerobic.
Anaerobic respiration (Plants and yeast)
Anaerobic respiration (Animals)
Anaerobic respiration in humans
Not enough oxygen may reach the muscles during exercise. When this happens, they use anaerobic
respiration to obtain energy.
Anaerobic respiration involves the incomplete breakdown of glucose. It releases around 5% of the energy
released by aerobic respiration, per molecule of glucose. The waste product is lactic acid rather than
carbon dioxide and water: glucose → lactic acid (+ little energy)
Useful products from respiration
Anaerobic respiration of microorganisms such as yeast can lead to the production of useful commodities.
During anaerobic respiration sugars are converted into ethanol. This is called fermentation.
When fermentation is performed on a larger scale using yeast, water, sugar and some other nutrients
bioethanol can be made that can be used as a biofuel.
Anaerobic respiration takes place in yeast and some bacteria, producing ethanol and carbon dioxide. They
have been used in the making of many foods such as bread, yoghurt and vinegar. You must know the
structure and functions of a bacterial cell and yeast cell.
1) Define the term respiration (Grade D)
2) Write a word and symbol equation for respiration. (Grade C)
3) Compare aerobic respiration with anaerobic respiration. (Grade B)
4) Illustrate an experiment which can be used to measure the rate of respiration. (Grade B)
5) Evaluate how heart rate, breathing rate, and respiration all alter when doing exercise compared to when resting.
(Grade A
Biology Experiments
Indicators:
EXPERIMENTS
Potential hazards
precaution
Microorganisms
Some bacteria
make us ill
Chemicals
Sulphuric acid can
burn skin,
alcohols can catch
fire easily
Fire
Unattended
Bunsen burners
Electricity
Faulty electrical
equipment could
give a shock
• Wear
gloves
• Tie hair back
• Wear
goggles
• Wash hands
• Use fire
proof matt
• No water
near
electricity
Measuring osmosis (living)
1. Cut up potato into
cylinders
2. Put some in sugar solution
and some in pure water
3. Measure length of
cylinders before and after
• Distilled water potato
swells up
• Concentrated sugar potato
solution shrinks
Measuring diffusion
1. Use scalpel to cut out agar
cubes (containing
phenolphthalein indicator
and sodium hydroxide)
2. Acid will diffuse into cubes
and turn them colourless
3. Repeat with different sized
cubes
Measuring light intensity and photosynthesis
iodine- tests for starch (starts orange,
turns blue/black if present)
Benedict's solutiontests for glucose
low
high
Hydrogen carbonate- shows change in
CO2 concentration
low
CO2
Normal
High
concentration CO2
Designing an experiment:
C-what you change, what are you investigating
O-what organism are you using
R-repeat
M-what you measure, ow you measure
S-thing you keep the same to make a fair test
Control variable to improve validity
Carry out repeats to improve reliability
Use smaller scales or more sensitive equipment to improve
precision
Improve method to improve accuracy (How close results are
to true answer)
Measuring osmosis (non-living)
1. Tie wire around one end of viscous
tubing, put a glass tube in other end and
tie
2. Put sugar solution down glass tube
3. Measure where liquid is up to
4. Put pure water into beaker and leave
overnight
5. Water will be drawn in and liquid will
move up tube
6. Re-measure where liquid is
Gas exchange in plants
1. Set up tubes with no leaf, 2. Use hydrogen
leaf and foil (no sunlight),
carbonate indicator
leaf in gauze (a little light)
to measure change
and a leaf in sunlight (lots of in co2 concentration
light)
The rate at which
pondweed produces
oxygen corresponds to the
rate of photosynthesis.
Adjust length away of
light from pondweed.
1. Leave pondweed to
photosynthesise for a 2. Use syringe to draw
set amount of time,
gas bubble up to ruler
oxygen will collect in
and measure
capillary tube
control
No
photosynthesis
More
photosynthesis
Respiration
than
and
respiration
photosynthesis
Calorimetry- measuring the energy in food
Increasing accuracy:
Insulate boiling
tube
• Hold food nearer
tube
• Make sure the
food sample is
completely burnt
out
thermometer •
25cm’ water
Mounted needle
with food sample
heat
Heat is lost to
surrounding air
and to glass tube
1. Weigh the sample of food
2. Measure temp of water
3. Burn food on mounted needle
under tube of water
4. Keep relighting until it no longer
learns
5. Measure final temp of water
Energy (J) = mass of water x temp change x 4.2
Energy per gram= energy in food
mass of food
Measuring transpiration (potometer)
Demonstrating CO2 production
Use hydrogen carbonate solution to show that living
organisms produce CO2 as they respire
1. Soak some dried beans in
water for 2 days until the
start to germinate (and
respire!)
2. Boil a second bunch so that
they die
Boiled Germinated
beans
beans
3. Put hydrogen carbonate
indicator into 2 test tubes
and put a platform made of
gauze into each
4. Seal with rubber bung and
leave for set time period
CO2 present
(respiration)
Ecosystem investigations
Estimating population size:
1. Place a 1m’ quadrat at a
random point of investigation
2. Count all the organisms within
the quadrat
3. Multiply by total area of habitat
4. Repeat at another area to compare population
sizes, or continue at more random places to calculate
an average
Measuring distribution:
1. Mark out a line on the area you are studying
2. Collect data along the line using quadrats next
to each other
Heat produced in respiration
thermometer
Cotton wool
Vacuum flask
Measure distance moved by air bubbletranspiration means water is lost through the leaves
so water is pulled upwards
Making it more accurate:
• Cut stem at a slant to increase water uptake
• Use a bung to prevent water evaporation
Measuring transpiration (using a balance)
Measure the change in weight
Making it more accurate:
• Use a layer of oil to stop evaporation
balance
Changing variables:
•
Light- use a lamp or put in cupboard
•
Temperature- use a heater
•
Humidity- spray water into air
•
Wind speed- use a fan
1. Prepare a set of
boiled dried
beans (control)
and one set of
germinated ones
2. Add each set to
Dead boiled beans
vacuum flask, but
make sure there
is some air so
beans can respire
aerobically
3. Put thermometer
in each and seal
with cotton wool
4. Record the temp
of each flask for a
Soaked
month
germinated
beans
Temperature and enzyme activity
How fast a product appears- the breakdown of hydrogen Respiration rate of yeast with
enzymes
Measure rate of CO2 production when
peroxide using catalase
H2O2 H2O + O2
changing variables such as
1.
Put hydrogen peroxide solution with
temperature, concentration of sugar
a source of catalyse (e.g. a potato) in
solution…
a water bath at a constant temp
2.
Using upward delivery, measure
amount of oxygen produced per
minute
3.
Adjust temp of water bath and repeat
2
2
How fast a substrate disappears- breakdown of starch to maltose
using amylase
1.
Put starch solution containing amylase in
2.
3.
4.
a test tube in a water bath
Time how long it takes starch to disappear
by regularly sampling starch solution
Iodine solution will stop turning
blue/black when starch is no longer
present
Adjust temp of water bath and repeat
Testing a leaf for starch
1.
2.
3.
4.
5.
Kill leaf by dunking in boiling water to stop any chemical
reactions happening
Heat in water bath with ethanol to get rid of chlorophyll
Rinse leaf in cold water
Add iodine solution
If starch is present leaf will turn blue/black. Starch will be
present if leaf is photosynthesising
1. Mix together sugar, yeast
and distilled water
2. Attach bung with a tube
leading to second test tube
of water
3. Count how many bubbles
are produced in a given
period of time
4. Repeat with water bath at
different temperatures (or
change another variable)
Respiration is controlled by
enzymes so as temp increases,
o should rate of respiration
Photosynthesis experiments
Chlorophyll, CO2 and light are all needed for photosynthesis
1.
2.
3.
The light
test
Put a plant in a cupboard
to grow without light
Take leaf from plant and
test for starch
Will no change colour as
no starch can be made as
light is needed for
photosynthesis
The chlorophyll test
Use variegated leaves (only the
green parts contain chlorophyll)
1.
Expose the leaf to sunlight
2.
Test for starch using iodine
solution
3.
Only the green bit that
contained chlorophyll will turn
blue/back
The carbon dioxide test
Soda lime absorbsCO2
out of the air in the jar
1.
Leave plant in
sealed bell jar with
soda lime and
sunlight
2.
Test plant for
starch
3.
Will not change
colour as CO2 is
needed for
photosynthesis