Monera, protoctists, fungi and plants.
The Monera Kingdom.
The MoneraKindom contains unicellular prokaryotic organisms (without an organized nucleus), such as
The vital functions of bacteria.
Nutrition : Some bacteria are autotrophic but most are heterotrophic and they feed in
Saprophytes: These live on decomposing organic remains and they become
inorganic substances. In this way they enrich the soil.
Parasites: They feed on other living beings, harming them and causing
Symbionts: They live in close association with another living being and this
produces a mutual benefit such as those which live in our intestine. Some
bacteria live inside plants we eat, such as leguminous plants. Bacteria fertilize
the soil and provide plants with nutrients which are rich in nitrogen; plants
feed bacteria with sugar.
Interaction: Some of these organisms don´t move, some swim by means of
flagellaand some slide over surfaces. They live in all types of environments, even
extreme ones, such as thermal waters.
Reproduction: Bacteria reproduce asexually through successive cell divisions. In
this way they can form groups of millions, and these groups are called colonies.
Reproduction of bacteria
Types of bacteria
Coccus, spherical bacteria
Bacillus, rod shaped bacteria
Spirillum, bacteria with a helical or spiral shape
Vibrio, curved bacteria
The Protoctist Kingdom
Protoctists are unicellular and multicellular organisms. They are eukaryotes and very simple and they
never form tissues.
Protozoa and Algae
Protozoa:Protozoa are unicellular eukaryotic beings and most of them are heterotrophs. They
can be found in salt water, in pools or on the ground, except for few that live inside other living
things, to which they cause harm.
Nutrition. Some protozoa feed on small particles found in their environment. Most are
hunters and they feed on micro-organisms. A few are parasites and cause illnesses
such as malaria.
Interaction. Some protozoa are immobile but most move using different mechanisms
(see the picture on the following page).
Reproduction. They reproduce by dividing their cellular body into two or more
Algae: Algae are eukaryotic autotrophic beings. Their cells have walls, like plant cells. Most are
unicellular and they usually form colonies but the best knownalgae are multicellular (see
picture on the following page).
They perform photosynthesis because their cells contain chloroplast.
Most are aquatic (from fresh water or salt water).
Algae have been used in food for centuries. For example, a type of gel is extracted from them,
which is used to cultivate bacteria and make ice-cream.
The main function of algae in nature is to feed aquatic herbivores. When some algae
reproduce excessively they can cause serious problems in lakes and swamps.
Movement mechanisms of protozoa
Using a flagellum
- Using pseudopods
Red algae: Most of the species are marine and they are red because they have a red
Brown algae: Most are marine. They are brown due to a brown pigment that is found
Green algae: They can live in the sea and also in fresh water. They are green because
they have a green pigment called chorophyll.
The Fungi Kingdom
Fungi are eukaryotic heterotrophic organisms. Some are unicellular, such as yeast, and others are
multicellular; they don´t form tissues. Mushrooms are fungi. Their cells have a cellular wall, but they are
different to plant cells.
They vital functions of fungi
Some multicellular fungi are made up of fine threads called hyphae. It is easy to see them in
When the hyphae are packed tightly together, they form the mycelium. Example: mushrooms.
Fungi are heterotrophic. They feed in different ways:
Saprotrophsfeed on remains of dead organisms, like the remains of plants and
Parasites feed on plants or living organisms, and they cause illnesses.
Symbiontsfeed by associating with autotrophic organisms, which provide them with
the food they need.
Fungi produce special types of cells to reproduce, called spores, from which a new
fungus is created.
They usually live in the soil, in dark, damp places.
Some types of fungi
Fungi that form mushrooms and their reproduction
The Plant Kingdom
Plants are eukaryotic multicellular organisms. They are also photosynthetic.
Parts of a plant
A typical plant has organs, such as roots, a stem and leaves.
The root: The root secures the plant to the ground and absorbs water and mineral
nutrients from it.
The stem: The stem supports leaves, branches and fruits.
Leaves: The leaves are where photosynthesis and transpiration (the elimination of
excess water by evaporation of vapour) take place.
Flowers: The flowers of a typical plant have a calyx (or set sepals), a corolla (or set of
petals), male sex organs (the stamen), and female sex organs (pistils).
The vital functions of a plant
Nutrition: Plants are autotrophs because they make their own food through
Reproduction: Their reproduction is sexual (through seeds) or asexual (through spores
or with fragments of their bodies, for example stem cuttings).
Interaction: They live attached to the soil and they can´t move. They can, however,
make some movement, such as growing towards light or closing their leaves when
Classification of plants
Plants can be classified into two groups:
Plants with seeds: They are the plants which have adapted best to the environment
because they have flowers which contain reproductive organs and they have seeds
which propagate better than spores. Spermatophytes are divided into two groups:
plants with bare seeds called gymnosperms, and plants which have seeds inside a fruit
Plants without seeds: These are plants without flowers, which reproduce through
spores and need to live in wet environments to be able to reproduce.
Plants with seeds
Gymnosperms are plants with bare seeds. Angiosperms are plants with seeds enclosed inside fruits.
Characteristics of gymnosperms
Characteristics of gymnosperms
Conifers are the most abundant gymnosperms. They are called conifers because their flowers
group together to make cones. There are huge woods of conifers in cold regions of northern
hemisphere. Pine trees, cypresses and junipers are conifers. Gymnosperms have the following
They are woody plants. They are usually large shrubs and trees.
They have thin, waterproof leaves so they can live in extreme temperatures. Their
leaves are green all year round.
Their flowers are called cones. They are unisexual - they have male reproductive
organs and female reproductive organs separated in different flowers.
Their flowers don´t have calyx or corolla.
Their seeds aren´t protected inside a fruit.
Characteristics of angiosperms
Angiosperms are the most numerous plants and they adapt well to the terrestrial
environment: they can grow in cold, high mountains or in warm tropical areas. Angiosperms
have the following characteristics:
Most are deciduous trees – they lose their leaves in winter
They are herbs, shrubs and trees.
Their flowers have calyx and corolla.
They can be unisexual or hermaphrodite.
Hermaphrodite plants have the male reproductive organ (stamens) and the female
reproductive organ (carpel) in the same flower. The seeds are protected inside fruit. After
fecundation, the ovule changes into the embryo of the new plant. The carpel changes into the
fruit and this protects the seed and helps to disseminate it.
Plants with seeds
Developed female cone
Plants without seeds
Plants without seeds
Mosses are plants without tissues or organs. They reproduce by spores which are
formed in a capsule.
These plants absorb water and all the substances they need through their whole
surface. These substances are small so that they can be distributed throughout the
plant. Look at the diagram below to see the structure of moss.
Ferns are plants with roots, stems and leaves.
The stem of a fern is called the rhizome, and it grows horizontally underground. Large
leaves, called fronds, grow from the stem.
They reproduce by spores which are formed and which grow in a structure called the
sorus, on the underside of the fronds.