2. ASEXUAL REPRODUCTION
involves a single parent. It results in offspring that
are genetically identical to each other and to the
parent. All prokaryotes and some eukaryotes
reproduce this way. Asexual reproduction has several
different methods.
They include binary fission, fragmentation, budding,
parthenogenesis, vegetative, spore formation and
propagation.
6. BINARY FISSION
In binary fission, parent cell divides into
two equal halves called daughter cells.
Daughter cells are identical to each other
and to their parent cell.
Organisms like the amoeba,
bacteria, euglena, etc., exhibit binary fission.
7.
8.
9.
10. FRAGMENTATI
ON
happens when a parent organism breaks
into
fragments, parts or pieces, and each
fragment develops into a new organism. The
parent body divides into two or more fragments.
After some time, each fragment develops into a new
individual.
There are organisms that can replace or
restore their lost or damaged body part. This
process is called regeneration.
11.
12.
13. BUDDIN
G
happens when a parent cell forms a bubble-like
bud. While the new bud grows and develops, it
stays attached to the parent cell .
When the bud is fully developed, it breaks away
from the parent cell and forms a new organism.
The cycle continues.
14. THE PICTURE SHOWN
BELOW IS YEAST,
SHOWING NEW FORMED
BUDS STILL ATTACHED TO
THE PARENT CELL.
15.
16. PARTHENOGENES
IS
occurs when an embryo develops from
an unfertilized cell. It occurs in
invertebrates, as well as in some fish,
amphibians, and reptiles.
It is a natural form of asexual reproduction
in which growth and development of
embryos occur without fertilization by sperm.
17.
18.
19.
20. SPORE
FORMATI
ON
is type of asexual reproduction that uses spores as a
reproductive cell capable of developing into a new
individual without fusion with another
reproductive cell. Spores hence vary from gametes,
which must unite in pairs to reproduce.
are used in asexual reproduction, while
Spores
gametes
Spores are delivered by microscopic
are specialists of sexual propagation.
organisms,
parasites, algae, and plants.
21.
22.
23. VEGETATIVE
PROPAGATION
Through their vegetative parts such as leaves, roots,
stem, and buds, plants reproduce asexually. This is
known as vegetative propagation. Some examples for
this are onion bulbs, tubers of potato,
runners/stolon, etc.
Vegetative plant structures that emerge from
plant stems incorporate rhizomes, runners,
bulbs, tubers, and corms. Tubers can also
be root extensions. Plantlets develop from plant
leaves.
24. 1.
RHIZOMES
are modified stems that typically grow horizontally along the
surface of or beneath the ground. Rhizomes serve as storage
sites for growth substance like proteins and starches.
As rhizomes grow and extend, roots and shoots may arise
from segments of the rhizome and develop into new plants.
As they mature, new rhizome emerges. Certain grasses, lilies,
irises, and orchids propagate in this manner. Edible plant
rhizomes include ginger and turmeric.
25.
26.
27. 2.
RUNNERS
Moreover known as stolons, runners are specialized stems
that, not at all like rhizomes, develop from existing stems just
underneath the soil surface.
As they are propagated, the buds on the specialized
stems produce roots and stems. Those buds are more isolated
than the ones found on the rhizome.
28.
29.
30. 3.
BULBS
Bulbs are swollen parts of the stem inside which lie the central
shoots of new plants. They are usually underground and are
surrounded by plump and layered leaves that provide nourishment to
the new plant.
Examples of plants that use bulbs are shallots, onion and tulips
31.
32.
33. 4.
TUBERS
Tubers emerge from either the stem or the root
of the plant. Stem tubers develop from rhizomes
or runners that swell from storing nutrients while
root tubers develop from roots that are
modified to store nutrients and get too large
and produce a new plant.
Examples of stem tubers are potatoes and yams
or locally known as ube.
34.
35.
36. 5.
CORMS
The solid, enlarged underground stems that
store nutrients in their fleshy and solid stem
tissue are called corms.
They are sorrounded by papery leaves. Corms
vary from bulbs in that their centers comprises
of strong tissue whereas bulbs comprise of
layered clears out.
Example of plants that use corm is taro (gabi).
37.
38. 6.
PLANTLET
S
The miniature structures that arise from meristem
in leaf margins ic referred to as plantlets. They
eventually develop roots and drop from the “mother
leaf” or the leaves they grew on. Bryophyllum
daigremontianum (syn.
Kalanchoe daigremontianum), also known as mother of
thousands is an example of a plant that uses plantlets
to propagate. Kataka-taka plant is another example for
this.
39.
40.
41. Asexual reproduction occurs faster than
sexual reproduction. This is
an advantage for many organisms
exhibiting this mode of reproduction. It
allows them to outnumber other
organisms that reproduce more slowly.
42.
43. Microbes, for instance, may separate a
few times per hour. Beneath
perfect conditions, 100 microbes can
divide to produce millions of bacterial
cells in a number of hours!
44.
45. In any case, most microbes don't live
beneath perfect conditions. In case they did,
the whole surface of the planet would soon be
covered with them. Instead, their reproduction is
kept in check by limited resources, predators,
and their own wastes. This is applicable for most
other organisms as well.
49. Sexual reproduction requires
two parents. Humans and other higher
forms of animals and plants are
products of sexual reproduction. In
this type of reproduction,
parents produce reproductive cells
called gametes.
50.
51. These sex cells are produced through
meiosis. These gametes are
haploid cells, which means that the
male and female gametes contain
only half the number of chromosome
found in the cells of the organisms.
52.
53. The gametes have to unite. This process is called
fertilization. The fertilized cell is called a zygote.
This zygote is now a diploid cell, which means that
it has twice the number of chromosomes as
a gamete. The embryo takes some time to
develop and mature.
