A. CHARACTERISTICS OF LIFE (MRS. GREN)
Characteristic
Description
Movement
An action by an organism or part of an organism causing a
change of position or place.
Respiration The chemical reactions in cells that break down nutrient molecules
and release energy for metabolism.
Sensitivity
To detect or sense stimuli (changes) in the internal or external
environment and make appropriate responses.
Growth
A permanent increase in size and dry mass by an increase in
cell number or cell size.
Reproduction The process that makes more of the same kind of organism.
Excretion
Nutrition
Removal from the body of:
• waste products of metabolism;
• toxic materials;
• substances in excess of requirements.
Taking in of materials for energy, growth and development.
B. THE BINOMIAL CLASSIFICATON SYSTEM
Less groups
but larger
in size
Kids
Prefer
Candy
Over
Fresh
Green
More groups
but smaller
in size
•
Salad
Every organism has a binomial name that is decided by its Genus and species.
Examples of how this works
•
The binomial name of the tiger is Panthera tigris.
•
The tiger’s genus is Panthera.
•
The tiger’s species is Panthera tigris.
•
The binomial name of each organism is an internationally agreed system in which the
scientific name of an organism is made up of two parts showing the Genus and species.
Two organisms belong to the same species if they can
breed together to produce fertile offspring
•
Classification is traditionally based on studies of shape and anatomy (observations).
• Classification is now based on DNA bases sequences and amino acid sequences of certain
proteins. This is a much more accurate way of grouping organisms.
• Organisms which share a more recent ancestor (are more closely related) have
DNA base sequences that are more similar than those that share only a distant ancestor.
C. CLADOGRAMS
•
A gene is a DNA base sequence that codes for a protein.
•
Cladograms are branching diagrams that show how closely related in evolution different
organisms are.
•
DNA base sequences of a specific gene are compared in different organisms.
•
There will be less differences between organisms that are more closely-related as they
share a more recent ancestor.
Human
Chimpanzee
Macaque
•
The colours show the DNA bases that are the same in all three organisms.
•
Humans and chimpanzees show the most similarities for this DNA base sequence.
What a cladogram looks like
shortest distance
from a branch point
branching point =
when organisms
‘split’ and started
to evolve
differently
common ancestor = when
all of these organisms were
the same many years ago
•
•
•
•
•
Organisms A and B are the most closely related in evolution
(As) they share the shortest distance from a branch point
(So) they spilt from each other more recently
(So) they share a more recent ancestor
(So) they have the most similar DNA base sequences
D. THE FIVE KINGDOMS
ANIMAL
PLANT
FUNGI
Nucleus



X

Cell wall
X



Some
M
M
M - most
U - some
U
M - some
U - most
C
C
C
S
C
X

X
X
Some
Unicellular (U)
or
multicellular (M)
Simple (S)
or complex (C)
structure
Has chlorophyll
for
photosynthesis
PROKARYOTE PROTOCTIST
E. THE VERTEBRATES
•
These are animals that have a backbone.
•
Mammals and birds are warm-blooded. Their body temperature is kept constant.
Vertebrate group
MAMMALS
BIRDS
FISH
REPTILES
AMPHIBIANS
Examples
Human
Dolphin
Bat
Whale
Monkey
Penguin
Ostrich
Robin
Eagle
Seagull
Shark
Tuna
Salmon
Cod
Snake
Crocodile
Lizard
Turtle
Tortoise
Frog
Toad
Salamander
Newt
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Hair or fur
Feed young on milk
Give birth to live young
Have a placenta
Breathe using lungs
Feathers
Wings
Most can fly
Beaks
Lay eggs with a hard shell
Breathe using lungs
Fins for moving
Wet scales
External fertilisation (happens outside the body)
Breathe using gills
•
•
•
Dry, scaly skin
Lay eggs with leathery shells
Breathe using lungs
•
•
•
Smooth, wet, permeable skin
Live in water when young but on land when adult
Breathe using gills when young but use lungs
when adult
F. THE ARTHROPODS
•
This is the largest group of invertebrates, which do not have a backbone.
ARTHROPODS
•
•
•
Exoskeleton
Jointed legs
Segmented body
INSECTS
ARACHNIDS
CRUSTACEANS
MYRIAPODS
3 body parts
6 legs
Many have 4 wings
Compound eyes
2 antennae
2 body parts
8 legs
No wings
Simple eyes
No antennae
Chalky exoskeleton
10-40 legs
No wings
Simple eyes
4 antennae
Centipedes have
2 legs per segment
Millipedes have
4 legs per segment
No wings
2 antennae
G. THE PLANT KINGDOM
PLANTS
do not
produce
flowers
FERNS
No flowers
Leaves are called fronds
Reproduce using spores
produce
flowers
FLOWERING
PLANTS
MONOCOTYLEDONS
DICOTYLEDONS
One cotyledon in their seeds
Two cotyledons in their seeds
Leaves are strap-shaped
Leaves have parallel veins
A cotyledon is the
embryo and its food
stores in a seed
Leaves are broad and wide
Leaves have branching veins
Tap root system
Branched root system
Flowers
are usually
in multiples
of 3
Flowers
are usually
in multiples
of 4 or 5
H. DICHOTOMOUS KEYS
• Dichotomous means ‘dividing into two’.
• These keys include a series of paired statements or questions that lead to an organism being
identified.
• When designing a key yourself, look for ‘clear cut’ obvious features that can easily be
distinguished.
Has the animal got legs?
YES
Has it got wings?
NO
Has it got more than 8 legs?
YES
NO
Centipede
Spider
NO
Has it got a shell?
YES
Is it active at night?
YES
Moth
NO
Butterfly
NO
YES
Worm
Snail