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How is blood sugar regulated?
• Eating foods containing lots of carbohydrates puts
glucose into the blood from the gut
• The normal metabolism of cells removes the glucose
from the blood but if you do lots of vigorous exercise,
much more glucose is removed
• Insulin (a hormone secreted by the Pancreas) helps to
maintain the right level of blood glucose so your cells
get a constant supply of energy

Explain 2 Arguments FOR and AGAINST
taking performance enhancing drugs
FOR taking performance
enhancing drugs

AGAINST taking performance
enhancing drugs

• Athletes have the right to make
• It’s unfair – people gain an
their own decision about whether
advantage by taking drugs, not just
taking drugs is worth the risk or
through training
not
• Athletes may not be fully informed
• Drug free sport isn’t fair because
of serious health risks associated
different athletes have access to
with the drugs they take
different training facilities, coaches
and equipment

Biology B1 Quiz
Leah Broderick

The Pill –
An oral contraceptive that before
contained high levels of oestrogen and
progesterone
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g
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Tropism–
Growth of a plant in response to a
stimulus (e
...
Light, Gravity, Moisture)

Phototropism–
Growth of a plant in response to light

Geotropism or Gravitropism–
Growth in a plant in response to gravity

Auxin–
A plant hormone that controls growth
near the tips of shoots and roots

Performance enhancing drugs–
Drugs that athletes take to improve their
performance in sport
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g
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Some of
these are banned by law, some are
prescription-only and all are banned by
sporting bodies

Anabolic Steroids–
Improve the performance of athletes by
increasing their muscle size

Stimulants–
Improve the performance of athletes by
increasing their heart rate

Statins–
Hormones–
Prescribed drugs used to lower the risk of Chemicals messengers which travel in
heart and circulatory disease
...


Receptor Cell–
A cell that is sensitive to a stimulus
...

blood to activate target cells
...
A
group of them change stimulus energy
into electrical impulses

Neurone–
A nerve cell that transmits information
from the receptor cells to and from the
CNS very quickly

Effector–
Muscles and glands that respond to
nervous signals– muscles contract and
glands secrete hormones

Indicator Species–
Organisms that are very sensitive to
changes in their environment, so they
can be studied to see the effect of
human activities

Evolutionary Relationships–
How all living things are related

Ecological Relationships–
How all living things interact with one
another

What food groups should you eat to have a
balanced diet and why?
• Carbohydrates – to release energy
• Fats – to keep warm and release energy
• Protein – for growth, cell repair and cell
replacement
• Fibre – to help the digestive system
• Small amounts of Vitamins – for healthy
functioning of the body

How does resting metabolic rate vary
between people?
• People with a higher proportion of muscle to
fat will have a high metabolic rate (muscle
needs more energy than fatty tissue)
• Physically bigger people have a higher
metabolism (they have more cells and
therefore they need more energy to be
supplied to each of them)
• Men have a slightly bigger metabolic rate than
women (they’re slightly bigger and have a
larger proportion of muscle)
• People who exercise more have a larger
metabolic rate (exercise builds muscle,
boosting your metabolic rate)

What happens if you eat too much?
• People who eat too much carbohydrate or fat can suffer from
obesity (common disorder, being 20% or more over the maximum
recommended body mass)
• Hormonal problems can lead to obesity, but it’s usually caused by
bad diet, overeating or lack of exercise
• Obesity can cause health problems: Arthritis (inflammation of
joints), type 2 diabetes (can’t control blood sugar level), high blood
pressure, heart disease and some types of cancer
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g
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• Some vaccinations wear off, therefore
booster injections are necessary to
increase the level of antibodies again

What are the advantages of Vaccination?
• They have helped to control lots of infectious diseases that
were once common
• Prevents epidemics (big outbreaks of disease) if a large
percentage of the population are vaccinated – this means that
people that aren’t vaccinated are less likely to catch the disease
as there are fewer people that can pass it on
...
Hot agar jelly is poured into Petri dishes
2
...
They then multiply
...
Paper discs are soaked in different types of antibiotics and
placed on the jelly
...

• The individual resistant bacteria will survive and reproduce (the
population will increase)
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g
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g
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• Other drugs (e
...
cold remedies) reduce the symptoms of an
illness without tackling the underlying cause of it
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g
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Different
antibiotics kill different bacteria (you must be treated with the
right one) – Antibiotics don’t effect viruses (e
...
influenza)
because they reproduce inside your cells (difficult to produce
drugs to kill them without damaging your own cells)

How did Semmelweis cut deaths by using
antiseptics?
• While working in a hospital in 1840s, Semmelweis saw that many
women were dying after child birth of puerperal fever (a disease)
• He believed doctors were spreading it on unwashed hands and told
doctors entering his ward to wash their hands in antiseptic solution –
the death rate decrease from 12% to 2%
• The antiseptic solution killed bacteria on their hands (Semmelweis
didn’t know this – microbes causing disease not discovered for 20
years) so he couldn’t prove how his ideas worked so his methods were
dropped when he left (death rates rose)
• Nowadays, it’s known that basic hygiene is essential for controlling
disease but recent reports show lack of hygiene has helped MRSA
spread in hospitals

What are the new dangers of bacteria?
• Bacteria can mutate to form new strains resistant
to the antibiotics usually used to clear the
infection or new strains that haven’t been
encountered before (no one’s immune), which
could spread and cause an epidemic
...

• This could be light, sound, touch, pressure, pain,
chemical, change in position or temperature

What are the 5 Sense Organs and what do
their receptor cells detect?
• Ears – Sound and balance
• Eyes – Light
• Nose – Smell; sensitive to chemical stimuli
• Tongue – Taste; sensitive to bitter, sweet, salt and
sour tastes and MSG (savoury) – this is chemical
too

What is the Central Nervous System (CNS)?
• Where all the information from the sense organs
is sent, and where reflexes and actions are
coordinated
• It consists of the brain and spinal cord

What are the 3 types of neurones?
• Sensory Neurones – nerve cells that carry
electrical impulses from receptors to the CNS
• Relay Neurones – nerve cells that carry signals
from sensory neurones to motor neurones
• Motor Neurones – nerve cells that carry signals
from the CNS to the effector

What does a synapse do?

• A junction between two
neurones which chemical pass
through
• The nerve signal is transferred
by neurotransmitters
(chemicals) which diffuse across
the gap and set of a new
electrical signal in the next
neurone

What are reflexes?
• Automatic responses to certain stimuli that reduce
the chance of getting injured
• Muscle example: someone shines a bright light in
your eye and your pupils automatically get smaller so
less light gets into the eye (stops it getting damaged)
• Gland example: if you get a shock, your adrenal gland
releases the hormone, Adrenaline automatically
• The passage of information in a reflex is called a reflex
arc

What happens in a Reflex Arc?
1
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g
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Impulses are sent along the sensory neurone
to the CNS
3
...
The same thing happens when the impulses
reach a synapse between the relay and motor
neurones
5
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g
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The effector responds (e
...
muscle contracts,
moving away from the source of pain)

Where are Hormones secreted from?
• The Pituary Gland secretes FSH and LH, which are involved in the Menstrual Cycle
• The Ovaries secrete Oestrogen which is also involved in the Menstrual Cycle
• Some other examples are shown in the diagram below:

What are Hormones?
• Chemicals messengers which travel in blood to activate
target cells
• They’re released directly into the blood and control this in
organs and cells that need constant adjustment
• They are carried to other parts of the body in blood
plasma (therefore they travel “at the speed of blood”) but
only effect certain cells called Target Cells
...
Causing an egg to mature in one of the
ovaries
2
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Causing the Pituary gland to produce LH
2
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Stimulating the release of an egg at
around the middle of the menstrual
cycle

What is Progesterone and what does it
control in the Menstrual Cycle?
• Progesterone is a hormone that is
produced by the Ovaries
In the Menstrual Cycle, Progesterone
is responsible for:
1
...
Day 1 - the bloodbath begins when the uterus lining breaks down for around 4 days

2
...
Day 14 – an egg is released from the ovary
4
...
If no fertilised egg has landed on the
uterus by day 28, the spongy layer starts to break down and the cycle starts again
...


What is The Pill?
• An oral contraceptive that before contained high
levels of oestrogen and progesterone
• The oestrogen in the pill caused side effects e
...
blood
clots, so now it contains lower doses of oestrogen to
reduce side effects
• A progesterone-only pill can also be used with fewer
side effects but it’s not as effective

How are hormones used to reduce fertility in
Contraception?
• Oestrogen can be used to prevent the release of an
egg if taken every day (level is always high) inhibiting
the production of FSH to stop egg development and
production for a long time
• Progesterone stimulates the production of thick
cervical mucus which prevents sperm reaching an egg

List 2 of the Pros and Cons of taking the Pill
Pros
• Over 99% effective at
preventing pregnancy
• Reduces risk of getting
some cancers

Cons
• Isn’t 100% effective – still
could get pregnant
• Has side effects e
...

headaches, irregular
periods and fluid retention
• Doesn’t protect you from
STD

How are hormones used to increase fertility?
• Some women have low levels of FSH so their eggs
don’t mature, meaning no eggs are released and they
can’t get pregnant
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g
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2
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4
...

2
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A shoot is growing sideways
Gravity produces an
unequal distribution of
auxin in the tip, with more
auxin on the lower side
This causes the lower side
to elongate faster, bending
the shoot upwards

Describe how Auxin effects the growth of a
plant in the roots
•Extra Auxin inhibits growth (cell elongation)
in the roots, meaning the side of a root with
the least Auxin will grow fastest
...

2
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4
...

2
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There is an uneven amount of
moisture either side of a root
More auxin is produced on
the side with more moisture
This inhibits growth on the
side with more moisture and
stimulates growth on the
other side, causing the root to
bend towards the moisture
...
Ion content
2
...
Sugar content
4
...
The skin as sweat
2
...
Urine from our kidneys and bladder
• On a cold day or when you’re not exercising, you don’t sweat much, so
you produce more urine which will be pale (less concentrated as there’s
more water)
• On a hot day or when you’re exercising, you sweat a lot so you produce
less urine which will be more concentrated and darker
...
You can’t
use human cells and tissues to test drugs that affect whole or
multiple bodies (e
...
you can’t test a drug for blood pressure on
cells as there is no circulatory system)
• Drugs are tested on live animals to test their toxicity, effect, the
best dosage (a low dose is given which is gradually increase)
...
A very low dose is firstly given, which is gradually
increased
• Then, the drugs are tested on people suffering from the illness to find the
optimum dose (dose that is the most effective with few side effects)
• To test how it works, the patients are put into two groups – one is given
the new drug, and the other is given a placebo (a substance like the drug
being tested)
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How are desert plants adapted to having
little water?

• Small surface area compared to volume – plants lose
water vapour from the surface of their leaves
...

• Water storage tissues – e
...
cacti store water in their
huge stems
• Maximising water absorption – some cacti have
shallow but extensive roots to absorb water quickly
over a large area when it rains in the desert
...

• Camouflage – sandy colour helps them avoid
predators and sneak up on prey
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g
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g
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Some invertebrate animals like
Mayfly larvae are good indicators – if there are lots of Mayfly larvae, the oxygen
concentration is high so the water is clean
• Other invertebrate animals are adapted to live in polluted conditions so if you see
lots of them, there is lots of water pollution – e
...
rat-tailed maggots, sludgeworms

How are non-living indicators used to measure
environmental changes?
• Satellite are used to measure the temperature of the sea surface and the
amount of snow and ice cover (modern, accurate instruments and give us
global coverage)
• Automatic weather stations tell us about the atmospheric temperature at
various locations (contain thermometers that are sensate and accurate)
• Rain gauges are used to measure how much the average rainfall changes
every year
• Dissolved oxygen meters are used to measure the dissolved oxygen
concentration in water and the change in water pollution

What do Pyramids of Biomass show?
• Each bar on a pyramid of biomass shows the mass of living material at that
stage of the food chain

Pyramids of Biomass

Energy Transfer and Decay

Describe the 7 stages of the Carbon Cycle
1
...
The carbon is
used to make carbohydrates, fats and proteins
2
...
This carbon then moves through the food chain
3
...
When plants, algae and animals die, detritus feeders (Detrivores) and
microorganisms eat and digest their remains (body, faeces, etc
...
Compounds from the animals’ remains are taken up by plants through the soil
as nutrients, putting the carbon back into the food chain
6
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g
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The cycle starts agains

The Carbon Cycle

What is a Variation within a species?
• Differences between organisms of the same
species
• Examples include hair colour, eye colour, height
and nose shape

How is Genetic Variation influenced by Genes?
• All plants and animals have similar characteristics to their
parents – this is because an organism’s characteristics are
determined by the genes inherited from their parents
• These genes are passed on in gametes, which the offspring
develop from
• Most animals get some genes from their mother and father
– this combination causes genetic variation (no two
organisms of the same species are genetically identical,
apart from identical twins)

List 3 characteristics that are determined by
Genes only
• Eye colour
• Blood group
• Inherited disorders (e
...
cystic fibrosis,
haemophilia)

What is Environmental Variation?
• Environmental variation is when
the environment that an
organism lives in causes
differences between members of
the same species
• An example of this is leaf colour
in plants
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g
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X-shaped chromosome has two identical
halves
2
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e
...
A membrane forms around each set and the
DNA replicates itself to form two identical
cells with sets of X-shaped chromosomes

What is the difference between ‘Sexual’ and
‘Asexual’ Reproduction?
Asexual Reproduction
• Requires one parent
• Involves body cells
• Creates offspring that are
genetically identical to the parent
(clones)
• Does not result in Genetic Variation

Sexual Reproduction
• Requires two parents
• Involves Gametes (sperm and egg)
• Creates offspring that are not
genetically identical to the parents
• Results in Genetic Variation (23
pairs of chromosomes are
inherited by the offspring from
each parent)

How do you clone plants?
• Cuttings: Taking cuttings from a good parent plan and
then planting them to produce genetically identical copies
of the parent plant – these are produced cheaply and
quickly
• Tissue Culture: A few plant cells are put in a growth
medium with hormones into new plants (clones of the
parent plant) – these can be made very quickly, in very
little space and all year round
...

• The sperm are then used to artificially fertilise an egg cell
...

• These cloned embryos can be implanted into lots of other cows where
they grow into baby calves (which will be genetically identical to each
other)

How do you make animal clones using adult cell
cloning?
• This technique was used to create Dolly – the famous cloned sheep
1
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2
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g
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The egg cell is stimulated by an electric shock, making it divide (like a
normal embryo)
4
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An unfertilised egg is taken from the ovaries and its genetic material (the
nucleus) is removed
...
A complete set of chromosomes from an adult body cell (e
...
skin cell) is
inserted into the ‘empty’ egg cell
3
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When the embryo is a ball of cells, it’s implanted into an adult female (the
surrogate mother) to grow into a genetically identical copy (clone) of the
original adult body cell

What are the Pros and Cons of Cloning
Pros of Cloning

Cons of Cloning

• Cloning quickly gets you lots of ‘ideal’ offspring
• The study of animal clones could lead to a
greater understanding of the development of
the embryo, and of ageing and age-related
disorders
• Cloning could be used to help preserve
endangered species

• Cloning gets you a ‘reduced gene pool’ – this
means there are fewer different alleles in a
population
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g
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A useful gene is ‘cut’ from one organism’s chromosome using
enzymes
2
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1
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g
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Sheep have been genetically engineered to produce substances, like
drugs, in their milk that can be used to treat human diseases
3
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Scientists are trying to treat these disorders by inserting working genes
into sufferers (this is called Gene Therapy)

What are the Pros and Cons of Genetic
Engineering?
Pros of Genetic Engineering

Cons of Genetic Engineering

• Has the potential for solving
• There are worries about the
many of our problems (e
...

long-term effects of genetic
treating diseases, more efficient
engineering e
...
changing a
food production)
person’s genes might
accidentally create unplanned
problems, which could then be
passed on to future generations

What are the Pros and Cons of GM Crops?
Pros of GM Crops

Cons of GM Crops

• GM crops can increase the yield of a crop, • Growing GM crops will affect the number
making more food
...
GM crops
around the crops, reducing farmland
could be engineered to contain the
biodiversity
...
g
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natural environment e
...
the herbicide
resistance gene may be picked up by
weeds, creating a new ‘superweed’ variety

How are organisms classified into groups?
• They groups are based on the similarities and differences between the
organisms
• Plants make their own food (by photosynthesis) and are fixed in the
ground
• Animals move about the place and can’t make their own food
• Microorganisms are different to plants and animals e
...
bacteria and
single-celled

How do Evolutionary Relationships work?
• Species with similar characteristic often share similar genes because they
share a recent common ancestor, so they’re closely related, often looking
alike and living in similar habitats (e
...
Whales and Dolphins)
• Occasionally, genetically different species may look alike (e
...
Dolphins and
Sharks - they’re both adapted to living in the same habitat and so look
similar, but are not closely related and have evolved from different
ancestors)
• Evolutionary Trees show common ancestors and relationships between
organisms
...


How do Ecological Relationships work?
• Organisms with similar characteristics, living in the same environment (e
...

Sharks and Dolphins) suggest that they might be in competition (e
...
for
food, territory, etc
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g
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g
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g
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g
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g
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• Therefore, the beneficial characteristic is more likely to be passed on to the
future generation by Natural Selection
• Over time, this beneficial mutation will accumulate in a population
e
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some species of bacteria have mutated to become resistant to
antibiotics, ensuring their survival

Why did people disagree with Darwin’s Theory of
Evolution?
• It conflicted with religious beliefs at the time about how life on Earth
developed, being the first plausible explanation for our existence without
the need for a ‘Creator’
• Darwin couldn’t give a good explanation for why these useful
characteristics appeared or exactly how individual organisms passed on
their beneficial characteristics to their offspring
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g
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g
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They might have different beliefs (e
...
religious) or have been influenced by
different people (e
...
other scientists and their way of thinking)
2
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g
...

• Darwin’s hypothesis was accepted because of the discovery of genetics, providing an
explanation of how organisms born with beneficial characteristics can pass them on
(through their genes)



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