bio ppt on reproduction in plants igcse

1. G R A D E : 9 I G C S E A
S U B J E C T : B I O L O G Y
T O P I C : R E P R O D U C T I O N I N
P L A N T S
S T U D E N T N A M E : A N Y A & S W E T H A

2. WHAT IS
REPRODUCTION ?
Reproduction is the biological
process by which new individual
organisms – "offspring" – are
produced from their "parent" or
parents.

3. THE TYPES OF REPRODUCTION :
ASEXUAL
 Requires only one parent.
 The offspring is genetically identical.
SEXUAL
 Formed by the involvement of two parents
I.e. when the fusion of the nuclei of two
gametes take place to form a zygote.
 The offspring produced is genetically
different from each other.

4. ASEXUAL SEXUAL

5. GAMETES
a mature
haploid
male or
female sex
cell which
is able to
unite with
another of
the
This Photo by Unknown author is licensed under CC BY-SA.

6. DIPLOID VS HAPLOID
DIPLOID
• A cell or nucleus that
contains two complete
sets of chromosomes
• Zygotes are diploid
HAPLOID
• A cell or nuclues with a
single set of
chromosomes.
• Gametes are haploid

7. MITOSIS VS MEIOSIS
MITOSIS
• Division of a cell
nucleus
• resulting in two nuclei.
• The two nuclei
are genetically identical
(I.e they contain
the same no. of
chromosomes of the
MEIOSIS
• Division of a diploid
nucleus
• Resulting in four nuclei
• The four nuclei are
genetically different

8. REPRODUCTION IN
FLOWERING PLANTS
• Flowers can reproduce in both ways : sexual and
asexual
• The function of a flower is to :
1) make gametes
2) ensure fertilization takes place
• Most flowers produce both male and female
gametes thereby also known as hermaphrodite

9. SEXUAL REPRODUCTION IN FLOWERS
Stigma: receives
pollen
Style: connects stigma to
ovary
Ovary: holds the
ovules
Ovule: contain
the female
gamete
Anther: pollen grains are
made here
Filament :the stalk
part of a stamen
Petals : attracts
pollinators
Sepal : protects
the flower when
it’s a bud
Flower
stalk
Carpel : female part
of the flower
Stamen: the
male part of
the flower

10. POLLEN GRAINS
Young anther:
Developing pollen
grains
Mature anther :
The pollen grains are mature
so they burst out

11. P O L L I N A T I O N
T H E T R A N S F E R O F
P O L L E N F R O M A
M A L E P A R T O F T H E
P L A N T T O T H E
F E M A L E P A R T ( T O
A S T I G M A , O V U L E ,
F L O W E R , ) T O
A L L O W
F E R T I L I Z A T I O N .

12. TYPES OF
POLLINATION
•There are mainly 2 types of
pollination- Insect
pollination and Wind
pollination

13. INSECT
POLLINATION
In insect pollination, The pollen
grains have a spiky texture and
thus allowing them to stick onto
insects more easily
Insect pollinated flowers have
petals which have stigmas
present inside them so that
insects brush past them to reach
the nectar

14. WIND POLLINATION
In wind pollination, the pollen grains have a smooth
surface and thus allowing them more surface area
Wind pollinated flowers have flexible anthers which
allows them to swing in the wind and release pollen
These flowers also have feathery stigma which
increases the surface area which results in higher
chances of successful pollination
These flowers also do not have petals
They tend to produce more pollen compared to insect
pollination as the chances of wind pollination is low.
This will help to increase these chances.

15. SELF POLLINATION
• Self
pollination
occurs when
pollen is
carried to
the stigma
of the same
flower or to
another

16. CROSS POLLINATION
•If pollen is
transferred to
a flower on a
different plant
of the same

17. FERTILISATION
Fertilization can be defined as the
fusion of the male gametes (pollen)
with the female gametes (ovum) to
form a diploid zygote. It is a
physicochemical process which
occurs after the pollination of the
carpel. The complete series of this
process takes place in the zygote to
develop into a seed.
In flowers, the pollen grain
germinates after the pollination of
the carpel and grows into the style
by creating the pathway for the
pollen grain to move down to the
ovary.
The pollen tube opens into the
ovule through the micropyle and
bursts into the embryo sac. Here,
the male nucleus unites with the
nucleus of an egg inside the ovule
forming a diploid zygote, which
later swells up and develops into a
fruit.

18. SEEDS
Once fertilization has occurred, the sepals, petals and stamens
dry up and fall off
The ovary contains ovules which contain zygotes
These zygotes divide by mitosis to form an embryo plant
known as seed

19. NOW LET’S LOOK AT AN
EXPERIMENT!
• The focus on this experiment is to
understand the conditions needed for
germination
• The main conditions required for
germination are- water and oxygen and
temperature must be warm
• In test tube A, It can be observed that it has
water, oxygen which diffuses through the
cotton and a warm temperature thus
germination will take place
• In test tube B it has all conditions except
temperature therefore germination will not
occur
• In test tube C, It has all conditions needed
for germination and thus it will occur
• In test tube D the oil is preventing oxygen
from entering the test tube, therefore no
germination will occur
• In test tube E there is no water present
therefore germination will. Be unsuccessful

20. A FEW DIFFERENCES
BETWEEN ASEXUAL
AND SEXUAL
REPRODUCTION:
In asexual production there is no genetic variation, that is the baby
plant is exactly like the parent plant as no new chromosomes are
involved in the reproduction process. This may be a disadvantage as if
the parent plant has a disease this may be inherited by the baby plant
as well
In sexual reproduction the cells divide by mitosis, thus involving
genetic variation. This means that as 2 different sets of chromosomes
are used the child will have lesser chances of inheriting a disease from
either of the parents.
In asexual reproduction, the process is very fast as it requires only one
plant. It does not have to go through pollination and fertilization which
take months to finish.
In sexual reproduction the process almost takes 9 to 12 months to
finish, thus it would not be very profitable to farmers if they want
immediate yield

21. A FEW DIFFERENCES BETWEEN CROSS AND
SELF POLLINATION:
Self pollination has an
advantage if genetic
variation is to be
minimum, in cases where
the plant is adapted to its
habitat.
1
Cross pollination has a
great advantage of having
a higher chance of genetic
variation as it is involving
a completely different
plant
2
Self pollination is also
useful when there’s only
one plant in the
environment. It reduces
the difficulty of finding
another plant
3

22. THANK YOU!!