Characteristics
and
classification of
living
organisms
https://www.youtube.com/watch?v=zZtcMBTQaS4
Movement
Respiration
Sensitivity
Growth
Reproductio
n
Excretion
Nutrition
Movement
⮚
Movement is an action by an
organism or part of an
organism causing a change of
position or place
⮚
Most single-celled creatures,
and larger animals, move
about as a whole.
⮚
Fungi and plants make
movements with parts of their
bodies.
⮚
Movement does not
necessarily involve locomotion
(movement of an organism
from place to place)
Respiration
Respiration
❑
are the
chemical reactions in
cells that break down
Glucose + nutrient molecules and
oxygen release energy for
metabolism
Carbon dioxide ❑
All living organisms break
+ water down food to obtain
energy.
C6H12O6 + 6O2
❑
Most organisms need
oxygen for this (aerobic
6CO2 + 6H2O respiration) whereas
others are able to respire
without oxygen
Metabolism is the chemical reactions in the body's cells.
Sensitivity
⮚
Sensitivity is the ability
of living organisms to
respond to stimuli.
⮚
A stimulus is a change in
the external or internal
environment of an
organism.
⮚
Plants, for example,
respond to gravity. This
is known as geotropism.
Sensitivity
Living organisms are
also aware of their
internal environment
and are able to respond
to changes and restore
the body to its normal
state. This regulation of
the internal
environment is known
as homeostasis.
Growth
❑
Growth is a permanent
increase in size and dry
mass by an increase in
cell number or cell size
or both
❑
Bacteria and single-
celled creatures increase
in size.
❑
Many-celled organisms
increase the number of
cells in their bodies,
become more
complicated and change
their shape as well as
increasing in size.
Reproduction
❑
Reproduction are the
processes that make more of
the same kind of organism
❑
Offspring are produced by the
process of reproduction.
❑
Single-celled organisms and
bacteria may simply keep
dividing into two (eg. binary
fission).
❑
Many-celled plants and
animals may reproduce
sexually or asexually.
Excretion
Excretion involves the
removal of waste
products of metabolism,
from the body, such as
carbon dioxide ( a
product of respiration).
Living organisms expel
these substances from
their bodies in various
ways.
Nutrition
⮚
Nutrition is the process
of obtaining food for
energy, growth and
development.
⮚
There are two main
methods of obtaining
food – aututrophic
nutrition (green plants)
and heterotrophic
nutrition (organisms use
ready-made organic
compounds as their food
source).
Link the Word with the Description
Carnivore
Plant-eating animals
Meat-eating animals
Omnivore
Photosynthesis
The gas needed by green
plants to make food
Carbon dioxide Animals that eat
meat and plants
Herbivore The process by which green
plants make food using sunlight
TAXANOMY
CLASSIFICATION – a
method of scientific
taxonomy used to group and
categorize organisms into
groups such as a genus or
species.
These groups are known as
taxa.
Species
?
⮚
⮚
A species is a group of
organisms that can reproduce
to produce fertile offspring.
⮚
⮚
Smallest natural group of
organisms.
It has been
estimated that
there may be as
many as 8.7
million species!
About 2.16
million species
have been
described.
https://education.nationalgeographic.org/resource/biodiversity
The vast majority
have therefore
not been
identified.
The modern system of
putting different
organisms into certain
groups was developed
by the Swedish
botanist and zoologist
Carl Linnaeus in the
eighteenth century.
He gave each species
a Latin name,
consisting of the genus
and the species and is
known as binomial
nomenclature.
For example, the
scientific name for the
rabbit is Oryctolagus
cuniculus. It is known by
this name all over the
world by the scientific
community.
Similarly, the binomial
name for human beings is
Homo sapiens.
Homo is the genus, and
sapiens is the species.
https://www.youtube.com/watch?v=ehV-MmuvVMU
https://www.liveworksheets.com/yp2392589th
CLASSIFICATION SCHEMES
https://plantlet.org/diversity-in-living-organisms-five-kingdom-classification/
Classification
The largest group of
Kingdom organisms recognised by
biologists. But how
many?
Classification
The largest group of
Kingdom organisms recognised by
biologists. But how
many?
For many years most
biologists favoured the
use of two kingdoms,
Plants and Animals.
Modern classification
tends to favour the
adoption of 5 kingdoms –
Prokaryotes (Monera),
Protoctista, Fungi,
Plants and Animals
Classification
Kingdom
Monera
Bacteria and Blue-green algae
(Prokaryotes)
Protoctista Amoeba, Paramecium
Fungi Moulds, Mushrooms, Yeast
Algae, ferns and mosses,
Plants
conifers and flowering plants
Jellyfish, worms, arthropods, molluscs,
Animals echinoderms, fish, amphibia, reptiles,
birds and mammals.
https://www.youtube.com/watch?v=hiQCCN5oisw
Monera (Prokaryotes)
Bacteria are categorized underneath the Kingdom Monera.
They possess the following important features:
Bacteria are single celled organism
●
Do not have a nucleus surrounded by membrane
●
Occur everywhere and they are microscopic in nature.
●
They possess a cell wall and is formed of amino acids and polysaccharides.
●
Bacteria can be heterotrophic and autotrophic.
●
Bacteria can be classified into four types based on their shape:
Coccus (pl.: cocci) – These bacteria are spherical in shape
●
Bacillus (pl.: bacilli) – These bacteria are rod-shaped
●
Vibrium (pl.: vibrio) – These bacteria are comma-shaped bacteria
●
Spirillum (pl.: spirilla) – These bacteria are spiral-shaped bacteria
●
Monera has been divided into Archaebacteria and Eubacteria.
● Capsule - Some species of bacteria have a third protective covering, a capsule made up of
polysaccharides (complex carbohydrates). Capsules play a number of roles, but the most important
are to keep the bacterium from drying out and to protect it from phagocytosis (engulfing) by larger
microorganisms. The capsule is a major virulence factor in the major disease-causing bacteria,
such as Escherichia coli and Streptococcus pneumoniae. Nonencapsulated mutants of these
organisms are avirulent, i.e. they don't cause disease.
● Cell Wall - Each bacterium is enclosed by a rigid cell wall composed of peptidoglycan, a protein-
sugar (polysaccharide) molecule. The wall gives the cell its shape and surrounds the cell
membrane, protecting it from the environment. It also helps to anchor appendages like the pili and
flagella, which originate in the cytoplasm membrane and protrude through the wall to the outside.
The strength of the wall is responsible for keeping the cell from bursting when there are large
differences in osmotic pressure between the cytoplasm and the environment.
● Cell membrane - A layer of phospholipids and proteins, called the cell membrane, encloses the
interior of the bacterium, regulating the flow of materials in and out of the cell. This is a structural
trait bacteria share with all other living cells; a barrier that allows them to selectively interact with
their environment. Membranes are highly organized and asymmetric having two sides, each side
with a different surface and different functions. Membranes are also dynamic, constantly adapting
to different conditions.
● Cytoplasm - The cytoplasm, or protoplasm, of bacterial cells is where the functions for cell growth,
metabolism, and replication are carried out. It is a gel-like matrix composed of water, enzymes,
nutrients, wastes, and gases and contains cell structures such as ribosomes, a chromosome, and
plasmids. The cell envelope encases the cytoplasm and all its components. Unlike the eukaryotic
(true) cells, bacteria do not have a membrane enclosed nucleus. The chromosome, a single,
continuous strand of DNA, is localized, but not contained, in a region of the cell called the nucleoid.
All the other cellular components are scattered throughout the cytoplasm.
● Plasmids- One of those components, plasmids, are small, extrachromosomal genetic structures
carried by many strains of bacteria. Like the chromosome, plasmids are made of a circular piece of
DNA. Unlike the chromosome, they are not involved in reproduction. Only the chromosome has the
genetic instructions for initiating and carrying out cell division, or binary fission, the primary means
of reproduction in bacteria. Plasmids replicate independently of the chromosome and, while not
essential for survival, appear to give bacteria a selective advantage.
● Flagella - Flagella (singular, flagellum) are hairlike structures that provide a means of locomotion
for those bacteria that have them. They can be found at either or both ends of a bacterium or all over
its surface. The flagella beat in a propeller-like motion to help the bacterium move toward nutrients;
away from toxic chemicals; or, in the case of the photosynthetic cyanobacteria; toward the light.
● Nucleoid - The nucleoid is a region of cytoplasm where the chromosomal DNA is located. It is not a
membrane bound nucleus, but simply an area of the cytoplasm where the strands of DNA are found.
Most bacteria have a single, circular chromosome that is responsible for replication, although a few
species do have two or more. Smaller circular auxiliary DNA strands, called plasmids, are also found
in the cytoplasm.
● Pili - Many species of bacteria have pili (singular, pilus), small hairlike projections emerging from
the outside cell surface. These outgrowths assist the bacteria in attaching to other cells and surfaces,
such as teeth, intestines, and rocks. Without pili, many disease-causing bacteria lose their ability to
infect because they're unable to attach to host tissue. Specialized pili are used for conjugation, during
which two bacteria exchange fragments of plasmid DNA.
● Ribosomes - Ribosomes are microscopic "factories" found in all cells, including bacteria. They
translate the genetic code from the molecular language of nucleic acid to that of amino acids—the
building blocks of proteins. Proteins are the molecules that perform all the functions of cells and
living organisms. Bacterial ribosomes are similar to those of eukaryotes, but are smaller and have a
slightly different composition and molecular structure
Protoctista (Protista)
●
Eukaryotic organisms are unicellular
●
The nucleus is bound by a membrane
●
Include organisms which will not fit into other kingdoms
Fungi
●
The fungi are filamentous, excluding yeast (single-celled).
●
Their figure comprises slender, long thread-like
constructions called hyphae. The web of hyphae is called
mycelium.
●
The cell wall of fungi is composed of polysaccharides and
chitin.
●
Most of the fungi are saprophytes and are heterotrophic.
●
Some of the fungi also survive as symbionts. Eg. Lichens
fungi live in association with algae. Eg. Mycorrhizaome-
fungi live in association with roots of higher plants.
Plants
(Plantae)
●
The stem is usually entirely below ground and takes the form of a
structure called as rhizome.
●
In bracken, the rhizome grows horizontally below ground, sending up
leaves at intervals.
●
The roots which grow from the rhizome are called adventitious roots.
FERNS
●
Ferns produce gametes but no
seeds.
●
The zygote gives rise to the fern
plant.
●
The sporangia are formed on
the lower side of the leaf
●
The sprongia position depends
on the species of fern.
https://www.youtube.com/watch?v=WWtOxnWUmLw
FLOWERING PLANTS
●
Reproduce through seeds
EMBRYO
Embryo is further divided into
Radicle (baby root)
▪
Epicotyl (will become leaves and stem)
▪
Hypocotyl (stalk of the leaves)
▪
▪
Cotyledons ( the first leaf, also called storage unit of a seed, as it provides nutrients
to the different parts of Embryo)
THE ANIMAL KINGDOM (ANIMALIA
Animalia contains about 31 phyla
Arthropods
Crustacea Myriapods
Arachnids
(crabs, (centipedes
Insects (spiders
shrimps, and
and mites)
water fleas) millipedes)
Arthropods
Features
❖ The name arthropod means jointed limb
❖ They don’t have backbone, therefore they are called as invertebrates.
❖ They have hard firm external skeleton called a cuticle (exoskeleton)
❖ Their bodies are segmented and between the segments are flexible joints which allow
movement.
❖ Most arthropods, the segments are grouped together to form head, thorax and abdomen.
CRUSTACEA
LOBSTER
INSECTS
Insects differ from crustacea in
having wings, only one pair of
antennae and only three pairs of
legs.There are no limbs on the
abdominal segments.
Arachnids
Myriapods
VERTEBRATES
❏ Vertebrates are animals which have a vertebral column
❏ The vertebral column is sometimes called the spinal
column or just the spine and consists of a chain of
cylindrical bones (vertebrae) joined end to end.
❏ Each vertebra carries an arch of bone on its dorsal (upper)
surface.
❏ This arch protects the spinal cord which runs most of the
length of the vertebral column.
❏ The front end of the spinal cord is expanded to form a
brain which is enclosed and protected by the skull.
❏ The skull carries a pair of jaws which, in most vertebrates,
have rows of teeth.
vertebrates (phylum -chordata)
FISH
AMPHIBIANS
Their life cycle usually includes
an aquatic larval stage with gills
Land-living adults have lungs
Viruses
1. Viruses are not considered to be living.
1. Viruses are considered neither prokaryotes nor
eukaryotes.
1. Akaryota includes organisms having no cells. All
viruses are placed under akaryota.
1. Viruses consist of nucleic acid surrounded by a
protein coat called a capsid.These two components
are called a virion.
1. Virion are complete infectious virus particle.
Classification
Eg. Lion
Classification
Kingdom Animalia
Classification
Kingdom Animalia
Phylum Vertebrates
Classification
Kingdom Animalia
Phylum Vertebrates
Class Mammals
Classification
Kingdom Animalia
Phylum Vertebrates
Class Mammals
Order Carnivores
Classification
Kingdom Animalia
Phylum Vertebrates
Class Mammals
Order Carnivores
Family Felidae
(cats)
Classification
Kingdom Animalia
Phylum Vertebrates
Class Mammals
Order Carnivores
Family Felidae
(cats)
Genus Panthera
Classification
Kingdom Animalia
Phylum Vertebrates
Class Mammals
Order Carnivores
Family Felidae
(cats)
Genus Panthera
Species leo
Classification
Panthera leo
Dichotomous keys
⮚
A dichotomous keys is a set of
paired contrasting descriptions
which leads to through to the
identification of an unknown
organism.
⮚ Each key is made up of pairs of
contrasting features
⮚ Dichotomous means two
branches, starting with quite
general characteristics and
progressing to more specific
ones.
The use of DNA has revolutionised the process of classification
