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Biology - Unit B1
1 A Balanced Diet
1.1 You need to balance
the amount of energy
intake and energy
uptake.
1.2 Components
1.2.1 Carbohydrates =
immediate
supply of energy
1.2.2 Proteins =
growth and
repair
1.2.3 Fats = store
of energy
1.2.4 Vitamins and
Minerals =
shortage leads to
deficiency diseases
1.2.5 Fibre
1.2.6 Water
1.3 BMI
1.3.1 Gives an indication
about a persons ideal
body mass compared
to their height.
1.3.2 BMI = mass in Kg
/ (height in m)2
1.3.3 Underweight = 18.8 -
normal = 18.5 to 25
overweight = 25 to 30
obese = 30+
1.3.4 Metabolic Rate
1.3.4.1 The speed at which
chemical reactions
occur in the cells of
your body.
1.3.4.2 Affecting Factors = Inheritance - Proportion of
muscle to fat in your body - Gender - Age
1.3.4.3 Obesity
1.3.4.3.1 Health Problems = Coronary heart
disease - high blood pressure -
type 2 diabetes - cancer
2 Disease
2.1 A pathogen is a
micro-organism that carries
disease around your body
and makes you ill.
2.2 Bacteria make you feel ill by
injecting toxins into your blood
stream which are carried around
your body.
2.3 Viruses inject DNA inot a cell which
then creates small viruses, which causes
the cell to burst releasing the virus.
2.4 Barriers to infection
2.4.1 Nose - mucus lining preventing
the passing of pathogens
2.4.2 Mouth - mucus and acid in
the stomach so are killed in
the stomach
2.4.3 Skin - glands create antiseptic and
coats our skin in an oily substance
2.4.4 Eyes - tears produce lysozyme
which cleans our eyes.
2.4.5 Second Line of Defence
2.4.5.1 White blood cells called phagocytes
engulf the white blood cells and
destroy them.
2.4.5.2 Third Line of Defence
2.4.5.2.1 The Immune System
2.4.5.2.2 The white blood cells produce
different anti-bodies to lock
onto the antigen.
2.4.5.2.3 Every antigen needs its own
special antibody.
2.4.5.2.4 Antitoxins
2.4.5.2.4.1 Neutralise toxins that
bacteria dump in your
body.
2.4.5.2.5 Reproduction
2.4.5.2.5.1 Sexual
2.4.5.2.5.1.1 Occurs in both
animals and plants
2.4.5.2.5.1.2 Involves 2 parents and the joining of
the gametes
2.4.5.2.5.1.3 Results in
variation in the
offspring
2.4.5.2.5.2 Asexual
2.4.5.2.5.2.1 Involves only 1 parent
2.4.5.2.5.2.2 Results in clones and are
genetically identical
2.4.5.2.5.3 There is no variation
2.4.6 Vaccinations
2.4.6.1 Endemics are the spread of
disease in one country.
2.4.6.2 Pandemics is the spread of
disease across several countries.
2.4.6.3 Involves injecting a small harmful amount of the pathogen into
your immune system which then creates the antibodies needed
to fight it, in preparation for the real disease.
2.4.6.4 Genetically Engineered Insulin
2.4.6.4.1 DNA is a universal code
2.4.6.4.2 Transferring genes from ones species to
another is genetic engineering
2.4.6.4.3 The species that has had its DNA changed
is known as genetically modified.
2.4.6.4.4 GM bacteria are used to
produce insulin for diabetes.
2.4.6.4.5 GM Crops
2.4.6.4.5.1 To improve there quality or resistance to insects or herbicides.
2.4.6.4.5.2 Used to alter the
rate of growth
2.4.6.4.5.3 virus resistance
2.4.6.4.5.4 Contamination, may be unsafe, takes
years to come onto the market.
2.5 Antibiotic Resistance
2.5.1 When bacteria are
no longer killed by
antibiotics.
2.5.2 Happens when mutations
occur in the dividing of
bacteria.
3 Hormones and Fertility
3.1 A hormone is a chemical produced by
a gland in one part of the body,
released into your blood stream and
carried to a target organ where it has
an effect.
3.2 Hormone Glands include pituitary, thyroid,
Adrenal, Pancreas, ovaries and testes.
3.3 Menstrual Cycle
3.3.1 LH - produced in the pituitary -
target organ are the ovaries and
it causes egg release.
3.3.2 FSH - produced in pituitary - target organ
ovary - matures the eg and produces
oestrogen.
3.3.3 Increasing Fertilty
3.3.3.1 Involves the giving of FSH and LH in a
fertility drug to stimulate maturation of
eggs which can be used in IVF.
3.3.4 Decreasing Fertility
3.3.4.1 Pills are taken containing oestrogen
which prevents the release of FSH and
prevents the eggs from maturing.
4 Tropisms
4.1 Plant responses are called
tropisms, plants respond to
light, gravity and water.
4.2 A response to light is phototropism
4.3 A response to gravity is geotropism
4.4 A response to water is hydrotropism
4.5 Positively tropic means plant
grows towards a stimulus
4.6 Negatively tropic means plant
grows away from the stimulus.
4.7 Growth in Plants
4.7.1 The hormone auxin
stimulates a plant to grow
4.7.2 The auxin encourages the cells
to elongate and it moves down
the stem by diffusion.
4.7.3 Plant Hormones
4.7.3.1 Weed killers - the auxins cause
rapid growth in plants which lead
to plants growing them to death
e.g. agent orange
4.7.3.2 Rooting Powders - auxin causes
the roots to grow
4.7.3.3 Ethylene - Causes fruit
to ripen converting
starch into sugar.
5 Drugs
5.1 A drug is any chemical that alters the way the body
works.
5.2 Stimulants - Ecstacy, Cocaine
5.3 Depressants - Heroin, Nicotine, Alcohol
5.4 Key Words
5.4.1 Addiction = when a drug contains
an addictive chemical that alters
body chemistry and can cause
withdrawal symptoms.
5.4.2 Withdrawal = a range of
symptoms such as sweating
and tremors associated with
stopping taking an addictive
drug.
5.4.3 Tolerance = requiring larger and
larger doses to get the same
effect with the risk of overdose.
5.4.4 Gateway Drug = a drug that
leads to more addictive drug
use e.g. cannabis
5.4.5 Drugs in Sport
5.4.5.1 Beta Blockers = overcome nervousness
5.4.5.1.1 Natural Selection and Evolution
5.4.5.1.1.1 Evolution is a change over time
5.4.5.1.1.1.1 1. many young are born -
shortage of food
5.4.5.1.1.1.1.1 Charles Darwins
theory of how
evolution happens is
called natural
selection.
5.4.5.1.1.1.1.2 2. individuals show variation due to
spontaneous mutation
5.4.5.1.1.1.1.2.1 3. Genes allowing survival are passed to the next generation.
5.4.5.1.1.1.1.2.1.1 4. individuals most suited to the environment survive
and breed successfully.
5.4.5.2 Lean Mass Builders =
increases muscle growth
5.4.5.3 Diuretics = removes excess water
5.4.5.4 Stimulants = boosts physical activity
5.4.5.5 Painkillers = treats pain
6 Competition
in animals
6.1 Animals and plants have to
compete for limited resources.
The best adapted survive.
6.2 Compete for food, water, mate, territory.
6.3 Interspecies = compete
outside of species
6.4 Intraspecies = compete
within species
6.5 Adaptation
6.5.1 Special feature or behaviour that makes an
organism particularly suited to its habitat.
6.5.2 Adaptations may be
general or specific.
6.5.2.1 General = legs to walk or
fins to swim
6.5.2.2 Specific = multiple rows of
teeth for eating
6.5.2.3 Specific = adaptation
that makes the animal
unique to others.
7 Competition in Plants
7.1 Compete for light, water,
nutrients and minerals from
the soil
7.2 Adaptation
7.2.1 Plant adaptations include surface area of
leaves, water storage and root systems.
7.3 Competition = the
way plants compete
with each other for
their necessities.
8 Extremophiles
8.1 Hydrothermal Vents = extreme
temperature, pressure, acidity, no light.
8.2 Chemosynthetic bacteria =
Animals/plants use minerals out of
black smokers for growth and food and
they form the first steps of the food
chain e.g. crab
9 Environmental Change
9.1 Changes in the environment affect
the distribution of living
organisms.
9.2 Non living factors = change in temperature, water
availability, light levels, pH and amount of oxygen
available.
9.3 Living factors = arrival of new
competitor for food, arrival of new
predator, arrival of a new disease.
9.4 A living indicator is any
organism that is present in
a certain place that can
indicate whether it is
polluted or not.
9.5 Cloning
9.5.1 Taking a cutting
9.5.1.1 You leave one leaf on the
cutting and place it in a
plastic bag for the water to
evaporate. Put auxin on the
end of the cutting which
causes cell elongation and
grows.
9.5.1.1.1 DOLLY THE SHEEP
9.5.2 Tissue Culture
9.5.2.1 Hundreds of clones are made at the same time. The
cutting is sterilised and broken down and grown in
agar.
9.5.3 Embryo Transplantation
9.5.3.1 A fertilised egg divides and the cells are
implanted into surrogates before implanted
into the uterus, each cell divides into
identical embryos.
9.5.3.1.1 All offspring are genetically
identical in all of these
techniques