1. • Hello !
• I'm teacher Omnia you can call me
ms Nia
• I will be teaching you igcse biology
in a very fun and simple way hope
you enjoy your biology class with
me
3. Objectives
What is Biology?
What is life?
What are the characteristics of living
organism?
What is classification and why living
organisms are classified?
4. What is Biology?
The word biology is derived from two Greek words
Bios meaning life
Logos meaning study, reasoning
The study of life is called Biology
5. What is life……………?
A set of characteristic/traits, that are
present in all the living things but not in
nonliving.
6. All living things have to perform seven life
processes.
Do you know what they are……..?
MRS-GREN
Movement
Respiration
Sensitivity
Reproduction
Growth
Excretion
Nutrition
If something does not perform all
of the seven life processes then it
is not alive.
7. 1. Movement
Why do animals move?
To find food, water, shelter, to hide from
predators and to reproduce.
Animal Movement
8. 17/12/2023
1. Do plants move?
•Yes, plants do move, but
very slowly compared to
most animals.
9. 2. Why do plants move?
•Plants move towards sunlight
which they need to make food.
•Roots will move towards water
and gravity.
•Some flowers close during the
night.
10. 2. Respiration
Respiration is the process in which the cells of an organism
obtain energy by combining oxygen and glucose, resulting
in the release of carbon dioxide, water, and ATP
(energy).
food-----glucose---energy
Glucose + Oxygen ENERGY + Carbon dioxide + Water
Respiration
11. 3. Sensitivity
Sensitivity is the ability of living things to detect changes
in their surroundings and respond to these changes.
12. 17/12/2023
Humans have five senses; do you know what they
are?
Touch
Taste
Smell
Sight
Hearing
Skin
Tongue
Nose
Eyes
Ears
Which organs are
associated with these
senses?
14. 4. Growth
Animals grow until they
reach adulthood and then
stop growing.
Plants continue to grow
throughout their lives.
15. 5. Reproduction
17/12/2023
All organisms need to reproduce. Reproduction is the
making of new organisms. If organisms did not reproduce,
then once those organisms died there would be no more of
the species left.
16. 5. Reproduction
Some animals reproduce by laying
eggs.
Example: Birds
Some animals reproduce by giving birth to live young.
Example: Mammals
17. Plant Reproduction
17/12/2023
Some plants reproduce using the wind to carry pollen from
one flower to another.
Some plants reproduce
using insects or birds
to carry pollen from
one flower to another.
18. 6. Excretion
Excretion is the process where an organism gets rid of
waste products that would otherwise cause it harm.
20. Nutrition
17/12/2023
Green plants make their own food using
sunlight, water and carbon dioxide. This
process is called PHOTOSYNTHESIS.
Carnivores
Omnivores
Herbivores
21. Additional Characteristics
They all are made up of cells
Cell contain
• Cytoplasm
• Cell membrane
• DNA
• Ribosome
• Enzymes
When we study the living organism
under the microscope
Human skin Cells
22. Objectives:
Classification
Five Kingdoms of Life.
Distinct characteristics of each of the Five
Kingdoms of Life.
Characteristics of each Kingdom.
23. 1.2. Classification
Why do we need to classify living things?
There are about 1.4 million
species of discovered
organisms on the earth
We divide them into different
groups to make studying them
easier
24. I. Physical appearance
• All the organism with similar
phenotype/characteristics are put in one group
e.g. Morphology
Anatomy
II. Using DNA Sequences to help classification
Based on the arrangement of DNA Bases (ATCG)
Modern method of classification of species
25. The classification system
Swedish naturalist 1735
He divided all the different kind of
living things into groups called
species
12000 species
Linnaeus classification was based on
same appearance and same behavior
Linnaeus
27. Binomial system of classification
• Binomial = two names (genus and
species)
• Worldwide system used by scientists
• The genus always has a capital letter e.g.
Panthera leo is the binomial name for lion
28. Species
The smallest group of organisms
classified which can interbreed
with each other to produce fertile
offspring
30. Kingdom Animalia
Characteristics
Multicellular
Cells have nucleus but no cell
wall and chloroplast
Feed on organic substances
made by other living organism
Multicellular –
Cell wall – it helps in the process of photosynthesis
Chloroplast – helps in photosynthesis
Chlorophyll – gives pigment to the leaves of the plant
34. kingdom Protista
Contains quite a mixture of organisms
Characteristics:
Multicellular or Unicellular
Cells have a nucleus
Cells may or may not have a chloroplasts
Some feed by photosynthesis and other feed
on organic substances made by other organisms
38. Viruses
Viruses are not true living
things
They can do nothing until
they enter a living cell.
Diseases
Common cold
Influenza
AIDs( HIV)
39. Scientists do not classify a virus as a living thing. This is
because:
It does not show all seven processes for life
when it enters a cell, it changes the way a
cell works so it can make copies of the virus.
40. Characteristics of Viruses
Very small (100 times
smaller than bacteria)
No typical cell structure
Contain strand of DNA or
RNA
Surrounded by a protein
coat called Capsid
The only life process they
can show is the
reproduction inside the
host cell
41. 1.5. Classifying Animals
Phylum Vertebrates
Animals with a supporting rod
running along the length of the body
They have the backbone
(vertebral column)
Vertebrae=the bones that make up the spine
42. Class Fish
All live in water except for one or two
(mudskipper) which spend short period of time
breathing air
Characteristics
Vertebrate with
scaly skin
Have gills
Have fins
43.
44. Class Amphibians
Most of the amphibians live on land but they always go back
to the water to breed
Toad, Frogs and Salamanders
45. Characteristics
Vertebrates with moist scale-less skin
Egg laid in the water, Larva ( tadpole) lives
in the water
Adults often lives on the land
Larva has gills and Adult has lungs
47. Characteristics
They are vertebrate with Scaly Skin
Lay eggs with rubbery shells
They Don’t need go back to the water for
breeding because their eggs have water
proof shells which stops them from drying out
48. Class Birds
Birds lay eggs with hard shells
(like reptiles)
Characteristics
Vertebrate with feathers
Forelimbs have become wings
Lay eggs with hard shells
Endothermic
Have Beak
Heart has four chambers
51. Phylum Arthropods
Also known as invertebrates
They are more successful group, because they have
waterproof exoskeleton that allow them to live in the
dry conditions
They have many kinds on the earth than other
species
Characteristics
Several pairs of legs
Exoskeleton
52. Insects
They are mainly terrestrial
Arthropods with three pairs of legs
Two pairs of wings
Body is divided into head thorax and abdomen
Breath through trachea
53.
54. Most insects reproduce oviparously, i.e. by laying eggs.
The eggs are produced by the female in a pair of ovaries.
At the time of fertilization, the eggs travel along
oviducts to be fertilized by the sperm and are then
expelled from the body ("laid"),
55. Crustaceans
Crabs, Lobsters and woodlice
Characteristics
They breath through gills
Most of them live in the wet
places
Arthropods with more than four
pairs of legs
Breath through Gills
56. Fusion of a sperm with an egg,
Some crustaceans are parthenogenetic;
That is, they produce eggs that develop
without being fertilized by a sperm.
57. Arachnids
Spiders, Ticks and Scorpions
They are land-dwelling
Characteristics
Arthropod with four pairs of
jointed legs
Breath through gills
Internal fertilization.
58. Myriapods
These are the centipedes and millipedes
Characteristics
Body consist of many segments
Each segment has jointed legs
Fertilization is internal
Centipedes generally have a life span of 4 to 6
years
millipedes live for 1 to 10 years
59. Classification of Plants
Plants are organisms that have cell with the
cell wall made up of Cellulose
Some parts of the plants are green
green pigment (chlorophyll)
Which absorb energy from sunlight
The plant uses this energy to make glucose using
carbon dioxide and water from the environment.
this process is known as photosynthesis
61. Ferns
Fern have leaves called fronds
They don’t produce flower
They reproduce by mean of spores produced on
the underside of the fronds
Characteristics
Plants with roots, stems and leaves
Have leaves called fronds
Don’t produce flowers
Reproduce by spores
62.
63. Flowering Plants
They can be tiny or very large
Many trees are flowering plant
Characteristics
Plants with root stem and leaves
Reproduce sexually by means of
flowers and seeds
Seeds are produced inside the ovary
in the flower
64.
65. Flowering plants can be divided
into two main groups
1. Monocotyledonous
2. Dicotyledonous
68. Dicots or Dicotyledon
They have two cotyledons in their seeds
They frequently have tap root system
Their leaves are often broader than monocots
leaves, and they have network of branching
veins.
69.
70. Dichotomous Keys
A dichotomous key is a method for
determining the identity of
something.
It is like a road map made of
questions with a yes/no answer.
Depending on the answer we will
follow one path or another
71. Keys are used to identify organisms based on
a series of questions about their features
Dichotomous means ‘branching into two’
and it leads the user through to the name
of the organism by giving two descriptions
at a time and asking them to choose
Yes No
72. Each choice leads the user onto another
two descriptions
In order to successfully navigate a key,
you need to pick a single organism to
start with and follow the statements
from the beginning until you find the
name
You then pick another organism and start
at the beginning of the key again,
repeating until all organisms are named
