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Classification, five kingdoms

Plants
Animals
Fungi
Protoctists
Prokaryotes
- Autotrophs ( able
- Heterotrophs
- Saprophytes (feed
- Unicellular
- Unicellular
to make their
(can’t make their
off dead organisms)
- Nucleus
- No nucleus
own food)
own food
- Multicellular
- Multicellular
- Multicellular
- Rigid cell wall
- Rigid cell walls
and chlorophyll
Subdivisions of kingdoms
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
- Phylum Chordata, made up of animals that have supporting rod like structures that goes up the back of the body
- Invertebrate, no backbone
- Vertebrate, have a backbone
- How they absorb oxygen
- Lungs
- Gills
- Skin
- How they reproduce
- Fertilisation occurs internally
- Fertilisation occurs externally
- Oviparous (lays eggs)
- Viviparous (give birth to live young)
- How they regulate body temperature
- Homeotherms (warm blooded, body temperature kept constant by homeostasis)
- Poikilotherms (cold blooded, body temperature changes with external
temperature)
Ring species
-

Ring species, a group of related populations that live in neighbouring areas
In the diagram, each block is a specie, it shows that some can interbreed to make fertile
offspring but others cannot

Binomial System
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-

Binomial system helps to classify animals with a two part name
- First name – genus
- Second name – Species
Helps to
- Identify species, avoids confusion where common names mean different things in different places
- Study species, by identifying the name and species, scientists can share information on them
- Conserve species, easy to presume that two similar looking organisms are the same, could mean only one
species gets protected whilst the other goes extinct
- Target conservation efforts, can protect areas that have a wide variety of species in

Variation, causes for variation;
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Genes
- Animals have the similar characteristics to their parents, characteristics inherited
- Combining genes causes genetic variation + mutations
Environment
- Diet
- Exercise
- Temperature
- Light level
- Amount of water
Most characteristics are a mixture of genes and the environment
Continuous variation, no distinct categories
- E
...
humans can be a variety of heights not just short or tall
Discontinuous variation, two or more distinct categories
- E
...
there is only four blood group types not lots of different ones

Adaptions
Living in the deep sea
adaptions
- Some fish emit light,
attracts prey
- Huge mouths, scoop
particles up from the
sea bed
- Huge eyes adapted to
the dark
- Long feelers, help
locate prey

Volcanic vents, hydrothermal
vents
- Chemicals from them
support bacteria,
make their own food,
chemosynthesis
- Animals feed off of
bacteria
- Bacteria adapted to
cope with high
temperatures and
pressure

Polar bears (Arctic)
Penguins (Antarctica)
- Compact shape, small
- Insulating fat
surface area
- Oily feathers
compared to volume
- Huddle in groups,
– reduces heat loss
conserve heat
- Thick layer of blubber
- Streamlined body,
for insulation, acts as
reduce water
energy source
resistance, catch fish
- Greasy fur shreds
easier
water, reduces heat
loss
- Big feet, spreads
weight, stops them
sinking

Natural selection, organism best suited to the environment are more likely to survive
-

Fittest survive and reproduce
Evolution happens over time to get beneficial characteristics

Evidence to support evolution
DNA research
-

Shared common ancestors
Species diverged more recently
Gradual changes in DNA
Species more recently diverged have similar DNA

Resistant organisms
-

Gene resistance to e
...
chemicals

Validation of evidence
-

Scientific journals
Peer review
Scientific conferences

Speciation – occurs when populations of the same species become so different that they can no longer breed (development of
a new species)
1
...
Conditions, either side of the barrier conditions are different characteristics will occur – natural selection
3
...
Osmoregulation (regulating water content)
b
...
Blood glucose regulation (keeps glucose levels steady)
-

Negative feedback, changes in the environment trigger a response that counteracts it
- A rise in body temperature causes a response that lowers the body temperature
The internal environment stays around the norm, where cells work best
Only works within limits, if the environment changes to much then it may not be counteracted

Body temperature, controlled by the hypothalamus
-

-

Enzymes in the human body work best at 37c
Hypothalamus, part of brain, personal thermostat
- Contains receptors sensitive to blood temperature
- Receives impulses from receptors in skin (nerve endings)
When the hypothalamus detects a change it causes a response in the dermis (deep layer of skin)

When temperature receptors detect you’re TO HOT
Erector muscles relax, makes hairs lie flat
Lots of sweat produced, (containing water and salt),
Sweat evaporates – transferring heat from skin to the
environment, cooling you down
...


When temperature receptors detect you’re TO COLD
Erector muscles contract, hairs stand on end, traps an
insulating layer of air, helps to warm
Little sweat produced

Blood vessels near the surface of the skin constrict (shrink)
Vasoconstriction
Less blood flows near the surface, less heat transferred to
surrounding areas
...

The effector then responds accordingly
- Sensory Neurones
- Long dendrons and short axons
- Carry nerve impulses from the receptors to the CNS
- Relay Neurones
- Short dendrons and short axons
- Carry nerve impulses from sensory neurones to motor neurones
- Motor Neurones
- Many short Dendrons and one long axon
- Carry impulses from the CNS to the effectors
- Effectors
- Muscles and glands
- Muscles contract in response to a nervous impulse
- Glands secrete substances in response to a nervous impulse (Hormones)

Reflexes, automatic responses to certain stimuli, reduce the chances of being injured
-

-

E
...
Someone shines a bright light in your eyes, your pupils automatically get smaller so that less light gets into
the eye – this stops it getting damaged
The passage of information in a reflex (from receptor to effector) is called a reflex arc

Reflex arc, goes through the central nervous system
1
...

3
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5
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7
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- Shoots are positively phototropic – they grow towards the light
Gravitropism (Geotropism), the growth of a plant in response to gravity
- Roots are positively gravitropic – they grow downwards
Plant growth hormones allow plants to grow in response to stimuli
- E
...
auxin and gibberellin

Auxin, controls the growth at the tips of shoots and roots
-

Produced at the tips and then diffuses backwards to elongate the cells behind

SHOOTS ARE POSITIVELY PHOTOTROPIC
-when a shoot tip is exposed to light, more auxin
accumulates on the side that’s in the shade than the side
that’s in the light
...

- This response enables plants to absorb more light for
photosynthesis
...


ROOTS ARE POSITIVELY GRAVITROPIC
- When a root is growing sideways, gravity produces an
unequal distribution of auxin in the tip, with more auxin on
the lower side
...
This means
the cells on top elongate faster, and the root bends
downwards
...
The plants absorb
more water and minerals, which are needed for
photosynthesis
...
g
...


Infectious diseases
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Pathogens, microorganisms that cause disease
- Bacteria
- Protozoa
- Fungi
- Viruses
Water
Drinking or bathing in dirty water

Food

Contact

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Droplets from when you cough or sneeze
Body fluids from the infected

Animal
Vectors

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Touching contaminated surfaces

Air
Body
Fluids

-

Eating contaminated food

Animals that spread disease

Cholera, bacterial infection
- Diarrhoea
- Dehydration
Spread by water contaminated with diarrhoea from other
sufferers
Salmonella, a bacteria found on food kept too long or not
cooked properly
- Food poisoning
Athlete’s foot, a fungus
- Itchy skin
- Flaky skin
Touching the same surface as an infected person has e
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g
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g
...
g
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g
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2
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4

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