Organisms classified using
natural systems, giving information
about evoulutionary relationships
Similar organisms compete for food.
Organisms clasified into groups starts with kingdom ends with species
Energy flow and recycling
energy lost each
stage of food
chain
Food chaind
limited to small
number tropic
levels
Recycling of carbon
involves:photosynthesis, feeding,
respiration, decomposition
The recycling of bacteria involves 4 types of bacteria
Pyramids of biomas and numbers show
feeding relationships
Adaption and natural
selection
Darwins theory was widely critisised
but now it's widely accepted
heat loss on organisms depend on
surface area to volume ratio
Darwin - Natural selection. Involves variation,
competition, survival of fittest and selective reproduction
Organisms in hot dry areas adapt to: Increace heat
loss, move on sand, lack of water
Organisms in cold areas
adapt to: keep warm, move in
snow
Natural selection today:
Warfarin resistance in rats.
colour of peppered moths
Population, Pollution
and Sustainability
Conservation is important to:
protect food, prevent damage to
food chains, protect organisms
for medicuses, protect habitats
for people to visit
Heat loss from organisms
depends on their surface area to
volume ratio
Human population is
increacing exeptionaly
leads to: CO2 (global
warming), sulfur
dioxide (acid rain),
CFC's break down
ozone layer
remove waste, make food, suply
energy sustainably. Helps conserve
habitats and organisms
I want to fill space.It just looks wrong
without this
B1
Diet and Exercise
Fit - Ability to do exercise.
Healthy - free from disease
Balanced diet vary
according to age, gender,
activity, religion and
choice
BMI indicates if you're
overweight
EAR used to calculate protein
requirements. Depends on age,
pregnancy lactation
Blood pressure - 2 readings.
Diastolic and systolic
fat, smoking, alcohol increase blood pressure
High blood pressure
damages the brain amd
kidneys
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howdy doo
Drugs and disease
Class A, Class B,
Class C, Legal
Alcohol causes cirrhosis
of the liver
Deppresant and stimulus drugs affect nervous system by affecting transmission across synapses
Changes in lifestyle reduce risk of
cancer
Mosquito is vector carries malaria
Plasodium is a pathogen causes
maleria. Paracite, humans are the
host
Homeostasis and Plant hormones
Homeostasis is maintaining a constant
internal environment
Automatic systems in body keep
water, temp, co2 levelsconstant
Immunisation protects
against certain diseases
by using harmless
pathogens
insulin controlls bloodsugar. it
converts excess blood glucose into
glycogen
Auxins are involved in
phototrophism and geotrophism
Auxins are a group of plant hormones They shoot
curvature by cell elongation
Plant hormones have comercial uses. (weed killer,
rooting powder, controll of fruit ripening
The Nervous System
a nerve impulse
travels along the axon
of a neurone
Light rays are
refracted as they
pass through the
cornea and lens
The eye accomodates
by altering the shape
of the lens
A neurotransmiter
substance differs across a
synapse, so the nerve
impulse can pass to the next
neurone
Monocular vision has a wider field pf view but
poorer distance judgement then binocular
vision
A spinal reflex invilves a receptor, sencory, relay
and motor neurons and an effector
Long and short sight is caused by the eyeball
or lens being the wrong shape
A nerve impule travels along the axon of a neurone
Variation and
Inheritance
Alleles
are
different
versions
of the
same
gene
Sex is determined by
sex chromosones, XX in
female, YY in male
Most faulty alleles are recessive
Dominant alleles are exposed if present,
resccesive alleles are expressed in the adstence
of dominant allele
Being homozygous is having two identical
alleles.
Being heterozygous is
having two different
alleles
B3
DNA, Proteins and
Mutations
Science
Mutations may lead
to the production of
different proteins. This
is because a change
in bases in DNA can
change the amino
acid sequence
Proteins
are made
of long
chains of
amino
acids
Proteins can be structual, hormones, carrier molecules or enzymes
Enzyme activity is effected by pH and temperature. This is due
to: lower collision rates at lower temperatures, denaturing at
extremes of pH and high temperatures
enzymes are specific and work by a 'lock and key' mechanism
protein synthesis occours on
ribosomes in cytoplasm
the code needed
to produce a
protein is carried
from the DNA to
the ribosomes by
a molecule called
mRNA
Chromasones are long coils of DNA, divided up
into regions called genes
Proteins are coded
for by DNA. The
base sequence
codes for the order
of amino acids
Each emino acid is
coded for by three
bases
DNA looks like a
ladder that's twisted
Cell Devision and Growth
Gameses are produced
by meisois
In meiosis, the chromasone number is
halved and each cell is geneticaly different
New cells of growth are produced by mitosis.
The cells made by this are geneticaly identical
There are a
number of
differences
between plant
growth and animal
growth
Growth can be measured by a change
in wet mas, dry mas or length. Each
method has advantages and
disadvantages but dry mas is the best
measure
Being multicellular
allows organisms to be
larger, use cell
differentiation, be more
complex
Respiration and The Circulation
Arteries have thick elastic
walls and carry blood away
from the heart
Veins have large lumens and
valves and carry blood back to the
heart
Capillaries are
permable and link
arteries to veins
Anerobic respiration produces lactic acid which: builds
up in muscles causing fatigue, acuts as oxygen debt
and had to be broken down in the liver after exercise
Anerobic respiration takes place
during hard exercise when there
is insignificant oxygen there
The equasion for anerobic respiration is:
Glucose + Oxygen -> Carbon Dioxide + Water
Red blood cells carry oxygen around the body
and are especially addapted for this function
THe heart has four
chambers, vand is part of a
double circulatory system
Changing genes and cloning
Gene therapy involves changing a persons
genes to try and cure disorders
Genetic enginereing
can be used to
produce useful
products but raises
some ethical issues
A selective breeding program can produce organsims with desired characteristics but may reduce
gene pull leading to problems of inbreeding
Cloning plants is easier then cloning animals
because many plant cells retain the ability to
differentiate
Plants can be cloned by
tissue culture, which
provides a number of
benifits
New cloning technology
will: produce a number of
benifits, involve risks,
raise ethical issues
Dolly the sheep was produced by the process of neculear
transfer - this involves placing the nucleus of a body cell into an
egg