3. B1.4.1 Adaptations
a) To survive and reproduce,
organisms require a supply of
materials from their surroundings and
from the other living organisms there.
b) Plants often compete with each
there for light and space, and for
water and nutrients from the soil.
c) Animals often compete with each
other for food, mates and territory.
4. B1.4.1 Adaptations
d) Organisms, including
microorganisms have features
(adaptations) that enable them to
survive in the conditions in which they
normally live.
e) Some organisms live in
environments that are very extreme.
Extremophiles may be tolerant to high
levels of salt, high temperatures or
high pressures.
5. B1.4.1 Adaptations
f) Animals and plants may be adapted for survival in the
conditions where they normally live, eg deserts, the Arctic.
Animals may be adapted for survival in dry and arctic
environments by means of:
■ changes to surface area
■ thickness of insulating coat
■ amount of body fat
■ camouflage.
Plants may be adapted to survive in dry environments by
means of:
■ changes to surface area, particularly of the leaves
■ water-storage tissues
■ extensive root systems.
g) Animals and plants may be adapted to cope with specific
features of their environment, eg thorns, poisons and
warning colours to deter predators.
6. Each zone of this oak tree is home to a
distinctive community of organisms.
7. The Polar Bear
• Polar bears are well adapted for
survival in the Arctic. Their adaptations
include:
– A white appearance as camouflage from
prey on the snow and ice
– Thick layers of fat and fur for insulation
against the cold
– A small surface area to volume ratio, to
minimise heat loss
– A greasy coat that sheds water after
swimming
– Large furry feet to distribute their load and
increase grip on the ice.
8. The Camel
• Camels live in deserts that are hot and dry
during the day, but cold at night. Their
adaptations include:
– Large, flat feet to spread their weight on the sand
– Thick fur on the top of the body for shade, and
thin fur elsewhere to allow easy heat loss
– A large surface-area-to-volume ratioto
maximise heat loss
– The ability to go for a long time without
water - they don't store water in their humps, but
they lose very little water through urination and
perspiration
– The ability to tolerate body temperatures up to
42ºC
– Slit-like nostrils and two rows of eyelashes to
help keep out sand.
9. The Cacti
• Cacti are well adapted for survival in
the desert. Their adaptations
include:
– Stems that can store water
– Widespread root systems that can
collect water from a large area.
– In addition, cacti have spines instead of
leaves. These minimise the surface area
and so reduce water loss by
transpiration. The spines also protect
the cacti from animals that might eat
them.
10. The Venus Fly Trap
• Venus fly traps are adapted to areas
poor in nitrates and phosphates.
Their adaptations are:
– A closing trap when insects fly into it,
caused by contact with trigger hairs.
– Being able to digest insects.
11. B1.4.2 Environmental change
a) Changes in the environment affect
the distribution of living organisms.
b) Animals and plants are subjected to
environmental changes. Such changes
may be caused by living or non-living
factors such as a change in a
competitor, or in the average
temperature or rainfall.
12. B1.4.2 Environmental change
c) Living organisms can be used as indicators
of pollution:
■ lichens can be used as air pollution
indicators, particularly of the concentration of
sulphur dioxide in the atmosphere
■ invertebrate animals can be used as water
pollution indicators and are used as indicators
of the concentration of dissolved oxygen in
water.
d) Environmental changes can be measured
using non-living indicators such as oxygen
levels, temperature and rainfall.
13. How prey and predators are
linked
• More prey
• More food for predators
• More predators survive and reproduce
• More predators
• More competition for food
• Some predators die (starvation)
• Fewer predators
• More prey survive
14.
15. Lichen
Crusty lichens can
survive in more
polluted air
Leafy lichens
can survive a
small amount
of air pollution
Green, bushy
lichens need really
clean air
16. Blackspot Fungus
• Another indicator of air quality is the
blackspot fungus on roses. Blackspot
fungus grows well on roses in unpolluted
areas.
• It is killed by the presence of sulphur
dioxide that would be found in polluted air.
17. Indicators of water pollution
• Scientists can take samples of the
invertebrate animals living in a river to see
if it is polluted.
• Some invertebrates are able to live in
polluted water and some are not.
18. Indicators of water pollution
Polluted water – cloudy, smelly with low
levels of oxygen
Invertebrates found: Not many different
species. Mostly worms and leeches.
19. Indicators of water pollution
Slightly polluted water – less cloudy and
smelly, oxygen levels rising.
Invertebrates found: more species:
molluscs (snails), some beetles.
20. Indicators of water pollution
Clean water – clear water, high levels of
oxygen.
Invertebrates found: Many different species.
Will begin to find shrimps and mayfly larva
which will not tolerate any pollution.
22. B1.5.1 Energy in biomass
a) Radiation from the Sun is the source
of energy for most communities of living
organisms. Green plants and algae
absorb a small amount of the light that
reaches them. The transfer from light
energy to chemical energy occurs during
photosynthesis. This energy is stored in
the substances that make up the cells of
the plants.
b) The mass of living material (biomass)
at each stage in a food chain is less than
it was at the previous stage. The biomass
at each stage can be drawn to scale and
shown as a pyramid of biomass.
23. B1.5.1 Energy in biomass
c) The amounts of material and energy
contained in the biomass of organisms is
reduced at each successive stage in a
food chain because:
■ some materials and energy are always
lost in the organisms’ waste materials
■ respiration supplies all the energy
needs for living processes, including
movement. Much of this energy is
eventually transferred to the
surroundings.
24. Food Chains
• Food chains show the flow of
material in biomass and energy flow.
• All life needs energy to stay alive.
25. Food Chains
• Energy from the sun is absorbed by
green plants.
• These are called producers.
• Who are eaten by primary
consumers.
• Who in turn are eaten by secondary
consumers.
26. REMEMBER
• Energy cannot be created or
destroyed, it is only transferred.
• Either up the food chain or out by
movement, excretion, etc.
• Describe how energy lost as it travels through a food chain.
• Construct food webs.
• Describe how farmers try to reduce energy loss.
29. B1.6.1 Decay processes
a) Living things remove materials from the
environment for growth and other processes.
These materials are returned to the environment
either in waste materials or when living things die
and decay.
b) Materials decay because they are broken down
(digested) by microorganisms. Microorganisms
are more active and digest materials faster
in warm, moist, aerobic conditions.
c) The decay process releases substances that
plants need to grow.
d) In a stable community, the processes that
remove materials are balanced by processes that
return materials. The materials are constantly
cycled.
30. Decay
• Living things remove materials from
the environment for growth and
other processes.
• These materials are returned to the
environment either in waste
materials or when living things die
and decay.
31. Decay
• Materials decay because they are
broken down (digested) by
microorganisms.
• Microorganisms are more active and
digest materials faster in warm,
moist, aerobic conditions.
32. Decay
• The decay process releases
substances that plants need to grow.
• In a stable community, the processes
that remove materials are balanced
by processes that return materials.
• The materials are constantly cycled.
33. B1.6.2 The carbon cycle
a) The constant cycling of carbon is called the
carbon cycle. In the carbon cycle:
■ carbon dioxide is removed from the
environment by green plants and algae for
photosynthesis
■ the carbon from the carbon dioxide is used to
make carbohydrates, fats and proteins, which
make up the body of plants and algae
■ when green plants and algae respire, some of
this carbon becomes carbon dioxide and is
released into the atmosphere
■ when green plants and algae are eaten by
animals and these animals are eaten by other
animals, some of the carbon becomes part of the
fats and proteins that make up their bodies
34. B1.6.2 The carbon cycle
■ when animals respire some of this carbon
becomes carbon dioxide and is released into the
atmosphere
■ when plants, algae and animals die, some
animals and microorganisms feed on their bodies
■ carbon is released into the atmosphere as
carbon dioxide when these organisms respire
■ by the time the microorganisms and detritus
feeders have broken down the waste products
and dead bodies of organisms in ecosystems and
cycled the materials as plant nutrients, all the
energy originally absorbed by green plants and
algae has been transferred
■ combustion of wood and fossil fuels releases
carbon dioxide into the atmosphere.
37. B1.7.1 Why organisms are
different
a) The information that results in
plants and animals having similar
characteristics to their parents is
carried by genes, which are passed on
in the sex cells (gametes) from which
the offspring develop.
b) The nucleus of a cell contains
chromosomes. Chromosomes carry
genes that control the characteristics
of the body.
38. B1.7.1 Why organisms are
different
c) Different genes control the
development of different
characteristics of an organism.
d) Differences in the characteristics of
different individuals of the same kind
may be due to differences in:
■ the genes they have inherited
(genetic causes)
■ the conditions in which they have
developed (environmental causes)
■ or a combination of both.
39. Chromosomes and Genes
• Chromosomes, found in the cell nucleus, contain
many genes.
• A gene is a section of DNA, which carries coding
for a particular protein.
• Different genes control the development of
different characteristics of an organism.
• Many genes are needed to carry all the genetic
information for a whole organism.
40. The Human
• Humans have 23
pairs of
chromosome, so 46
on total.
• For sexual
reproduction only
one from each pair
is used.
41. Gametes
• Gametes are also known as sex cells.
• In a female this is the egg cell. In the
male this is called a sperm cell.
• The nucleus of each gamete contains
chromosomes. There are 23 pairs for
humans.
• Each chromosome carries thousands of
genes.
42. Variation
• In genetics, variation refers to an
individual that possesses
characteristics different from the
others of the same kind.
43. Causes of variation
• Variation is caused by genes or by
environmental factors or by a
combination of the two.
• Eye, hair and skin colour is caused by
genes.
• Physical scars are due to environmental
factors.
• Height and mass are a combination of
both.
44. Types of variation
• Continuous variation can vary gradually
from one extreme to another, for example
height.
• Categoric variation is usually caused by
a single gene and is one of a small number
of possible choices, for example eye colour.
• Decide which type of variation the
following are:
– Eye colour
– height
– mass
– skin colour
– hair colour
45. B1.7.2 Reproduction
a) There are two forms of reproduction:
■ sexual reproduction – the joining (fusion) of
male and female gametes. The mixture of the
genetic information from two parents leads to
variety in the offspring
■ asexual reproduction – no fusion of gametes
and only one individual is needed as the
parent. There is no mixing of genetic
information and so no genetic variation in the
offspring. These genetically identical
individuals are known as clones.
b) New plants can be produced quickly and
cheaply by taking cuttings from older plants.
These new plants are genetically identical to
the parent plant.
46. B1.7.2 Reproduction
c) Modern cloning techniques include:
■ tissue culture – using small groups of cells from part
of a plant
■ embryo transplants – splitting apart cells from a
developing animal embryo before they become
specialised, then transplanting the identical embryos
into host mothers
■ adult cell cloning – the nucleus is removed from an
unfertilised egg cell. The nucleus from an adult body
cell, eg a skin cell, is then inserted into the egg cell. An
electric shock then causes the egg cell to begin to
divide to form embryo cells. These embryo cells contain
the same genetic information as the adult skin cell.
When the embryo has developed into a ball of cells, it
is inserted into the womb of an adult female to
continue its development.
47. B1.7.2 Reproduction
d) In genetic engineering, genes from the chromosomes of
humans and other organisms can be ‘cut out’ using enzymes
and transferred to cells of other organisms.
e) Genes can also be transferred to the cells of animals,
plants or microorganisms at an early stage in their
development so that they develop with desired
characteristics.
■ new genes can be transferred to crop plants
■ crops that have had their genes modified in this way are
called genetically modified crops (GM crops)
■ examples of genetically modified crops include ones that are
resistant to insect attack or to herbicides
■ genetically modified crops generally show increased yields.
f) Concerns about GM crops include the effect on populations
of wild flowers and insects, and uncertainty about the effects
of eating GM crops on human health.
48. Sexual Reproduction
• Gametes required from male and
female parents.
• Each gamete contains half the number
of chromosomes needed for offspring.
• Large amount of variation.
49. Asexual reproduction
• Only one parent is required, cells
divide without the need for male
sperm.
• Offspring are identical to the parent,
known as clones.
• No variation.
50. Asexual reproduction
• Much faster than sexual reproduction.
• Some plants reproduce asexually.
• Cuttings can be taken from some
plants, this allows us to grow an
identical plant from a stem or leaf.
51. Cuttings from Plants
• Cuttings from plants produce identical copies.
• Can only get a limited number of clones at
one time.
• Damaging to mother plant
53. Embryo Transplant
• Eggs are taken from a desirable female
(animals).
• Sperm is taken from a desirable male.
• These are combined in a dish.
• A fertilised eggs is allowed to divide.
• This is then split into multiple embryos.
• Each of these embryos are put into less
valuable females.
• Genetically identical offspring are born.
54. Adult Cell cloning
Adult cell cloning involves several steps:
1. The nucleus is removed from an
unfertilised egg cell and discarded
2. The nucleus is removed from an adult body
cell and injected into the egg cell
3. An electric shock is applied to make the
egg cell begin to divide to form an embryo
4. While it is still a ball of cells, the embryo is
inserted into the womb of an adult female
5. The embryo continues to grow and develop
The new individual is genetically identical to
the animal that donated the nucleus from one
of its body cells.
56. Genetic Modification
• Genetic modification, or GM for short, is
not the same as cloning.
• Although cloning techniques are used in
genetic engineering, the two things should
not be confused.
• This table shows some of the differences.
Cloning Genetic Modification
Produces exact copies Produces a unique set
of genes
Genes copied within
same species
Genes can be swapped
across species
58. B1.8.1 Evolution
a) Darwin’s theory of evolution by natural
selection states that all species of living things
have evolved from simple life forms that first
developed more than three billion years ago.
b) The theory of evolution by natural selection
was only gradually accepted because:
■ the theory challenged the idea that God made
all the animals and plants that live on Earth
■ there was insufficient evidence at the time
the theory was published to convince many
scientists
■ the mechanism of inheritance and variation
was not known until 50 years after the theory
was published.
59. B1.8.1 Evolution
• c) Other theories, including that of
Lamarck, are based mainly on the idea that
changes that occur in an organism during
its lifetime can be inherited. We now know
that in the vast majority of cases this type
of inheritance cannot occur.
• d) Studying the similarities and differences
between organisms allows us to classify
living organisms into animals, plants and
microorganisms, and helps us to
understand evolutionary and ecological
relationships. Models allow us to suggest
relationships between organisms.
60. B1.8.1 Evolution
e) Evolution occurs via natural selection:
■ individual organisms within a particular
species may show a wide range of variation
because of differences in their genes
■ individuals with characteristics most suited
to the environment are more likely to survive
to breed successfully
■ the genes that have enabled these
individuals to survive are then passed on to
the next generation.
f) Where new forms of a gene result from
mutation there may be relatively rapid change
in a species if the environment changes.
61. Classification
• Classification – sorting organisms into
groups according to their characteristics.
• We start with kingdoms, the main ones
are: plant; animal; and microbe.
62. Natural selection
• Evolution happens due to natural selection.
– Individual organisms within a particular
species may show a wide range of
variation because of differences in their
genes.
– Individuals with characteristics most suited to
the environment are more likely to survive
and breed successfully.
– The genes that have enabled these individuals
to survive are then passed on to the next
generation.
63. Darwin
• Darwin’s theory of evolution by
natural selection states that all
species of living things have evolved
from simple life forms that first
developed more than three billion
years ago.
64. Darwin’s Theory in a nutshell
• A Giraffe is born with a slightly
longer neck due to mutation. (You
could also say there is a variation in
neck size, longer neck means better
survival).
• That gives is a better chance of
survival as it can get more food.
• The Giraffe survives and breeds.
• This means the genes are passed on.
• Giraffe’s child has a slightly longer
neck due to it’s genes.
65. The Problem with Darwin’s
Theory
• The theory challenged that god made
all the plants and animals that live
on Earth.
• There was insufficient evidence at
the time.
• The mechanism of inherence and
variation was not known for 50 years
after the theory was published.
66. Lamarck Theory
• His theory centred on two ideas:
– The law of use and disuse.
– The law of inheritance of acquired
characteristics.
• His theory says that a characteristic
which is used more and more by an
organism becomes bigger and
stronger. One that is not used
disappears eventually. Any
characteristic of an organism that is
improved through use is passed to
its offspring.
67. Lamarck’s Theory in a nutshell
• A swordfish used to have shorts swords.
• The sword grew longer as each swordfish
used its sword more and more.
• Each time a swordfish reproduced, the
longer sword was passed on to its
offspring.
THIS IS AN INCORRECT THEORY
BUT YOU NEED TO KNOW IT
