All living things will eventually leave
our planet, either by dying of old
age, disease or accidents. If living
organisms did not reproduce, life
would cease to continue in our planet
until each member of life forms
Nature ensures that life continues in
every type of living organism through
the process of reproduction.
Process by which organisms replace
themselves, the “old circle of life”.
Reproduction in Lower life forms
Plants, just like other living organisms, are also
part of the “circle of life”. They cannot live forever and
therefore each species of plants must replace
themselves with younger members. Plants do this in two
ways, asexually and sexually.
• does not involve the fusion of sex
•only one parent is required
•offspring are genetically identical to
parents known as clones
•involves fusion of two sex cells to form a zygote
•usually requires two parents
•offspring shows variations or not the exact copy of
Parts of the
•The new plant that results is
genetically identical to its parent plant.
•Can occur naturally or artificially with
the aids of humans
◘ Reproduction in plants from its vegetative
parts or specialized reproductive structures
Modified stem Description Representative Species
Tuber New shoots arise from axillary bud
on swollen, short, fleshy,
Runner New plants arise at nodes of
above-ground horizontal stem
Bermuda Grass, Strawberry plants
Corm New plants arise from every short
thickened, underground stem with
thin, scaly leaves
Rhizome New plants arise at nodes of
underground horizontal rootlike
Sugar cane, ginger
Bulb New bulbs arise from axillary bud
on very short stem with thick
fleshy leaves (only in monocots)
-various types of modified plant structures that are enlarged to
stems which grow at the soil surface or just below ground that form
adventitious roots at the nodes, and new plants from the buds.
-characteristically horizontal stem of a plant that is usually found
underground, often sending out roots and shoots from its nodes.
Rhizomes may also be referred to as creeping rootstalks or
a short stem with fleshy leaves or leaf bases. The leaves often
function as food storage organs during dormancy.
-Asexual methods practiced with a little help from
- Often faster than growing plants from seeds.
- Farmers propagate plants by using a piece of plant
- Each plant generated that is identical and genetically
the same as the parent tree is said to be a clone
Method Description Examples
Cutting Leaves or pieces of stems or roots
are cut from one plant, planted in
soil and used to grow new
Ornamental trees and shrubs
Budding and Grafting Small stems from one plant are
attached to larger stems or roots
of another plant.
Some fruit and nut trees
Pieces of tissues from one plant
are placed on a sterile medium
and used to grow new individuals
in mass numbers
Orchids, potatoes, many house
Methods of Vegetative Plant Propagation
•All flowering plants reproduce
•Sexual Reproduction happens in the
sexual organs of flowering plants.
•Most plants are Hermaphrodites
•Involves the fusion of sex cells from
Anther- makes tiny
which contain sex
Filament- holds up
Stigma- top part of
the carpel with sticky
surface to trap pollen
Style- joins the
stigma and the ovary
female sex cells called
-Transfer of pollen grains from the
stamen to the stigma
-Pollen grains produced in the anther
of one plant land of the stigma of the
flower of another plant.
-The stigma is often quite sticky, so
the pollen grains stick to it easily.
It is the transference of the pollen grains from the
anther to the stigma of either the same or of
another flower borne on the same plant.
Autogamy- The pollen grains are transferred from
the anther to the stigma of the same flower. It
occurs in bisexual flowers.
Geitonogamy- Flower is pollinated by pollen from
another flower on the same plant.
It is the transference of the pollen grains from the anther
of one flower to the stigma of another flower borne on a
different plant of the same species. It is also known as
allogamy or xenogamy.
Cross pollination increases variety and can give rise
to changes that help species survive.
In order to prevent overcrowding
and competition for basic needs,
such as space, light, and water, seeds
together with its fruit are sometimes
carried away from the parent plant
in a process called dispersal.
The process in which a new plant grows from a seed.
-Water – is needed for metabolism. The
uptake of water by seeds is called imbibition.
-Oxygen- is needed for respiration, which
breaks down food, releasing energy for
-Temperature- affects the cellular metabolic
and growth rate.