The document discusses flowers, their structures and functions. It defines flowers as compressed shoots bearing floral leaves that are the reproductive structures of plants. The main external parts of a flower are described as sepals, petals, stamens and pistils. Variations in flower structures and types of inflorescences are covered. The development of pollen grains and ovules is summarized, as are the processes of pollination, fertilization and fruit/seed formation.

1. FLOWERS

2.  At the end of my discussion, we should be able
to:
1. know what are FLOWERS and their external
parts and functions.
2. be familiar about the variations in flower
structures and their collective clusters.
3. know their development of pollen grains and
ovules, as well as the pollination and
fertilization processes.

3.  FLOWERS
A. External parts of a flower
B. Variations in flower structures
C. Inflorescence
D. Development of pollen grains and ovules
E. Pollination
F. Fertilization

4.  Is a compressed shoot bearing floral leaves.
 They are the reproductive shoots of
angiosperm sporophytes because they cease
growing and fruit are formed.
 They are the most colorful as well as the most
widespread and diverse members of the plant
kingdom.

5.  Are leaf-like usually colorful structures
arranged in a circle called corolla around the
top of a flower stem. They often have nectar
and perfume at their bases.
FUNCTION:
Petals support and protect the fertile structures
and also help attract pollinators.

7.  Are also leaf-like, usually green and encircle
the flower stem beneath the petals.
FUNCTION:
Like petals, sepals also support and protect the
fertile structures and also help attract
pollinators. It also cover the outside of a
flower bud to protect the flower before it
opens.

9.  Is the male reproductive structure of a flower.
It is made up of the filament and anther.
FUNCTION:
The main function of the stamen is to produce
pollens.

11.  Terminal structure which is a part of the
stamen.
FUNCTION:
Produces and contains pollens.

13.  The hair-like stalk of the stamen which bears
the anther.
FUNCTION:
To attached the anther to the flower stem.

15.  Female structure of a flower. Consists of
stigma, style, ovary and ovule.
FUNCTION:
The main function of the pistil is to produce
ovule.

17.  Is the sticky or feathery surface on which
pollen grains land and grow.
FUNCTION:
Receives and captures the pollen grains and on
which they germinate.

19.  Is the slender stalk of the pistil that the stigma
sits on top of.
FUNCTION:
Connects the stigma to the ovary and the place
where pollen tube grows.

21.  The enlarge basal portion of the pistil. The
structure formed at the lower end the pistil.
FUNCTION:
Place where ovule/s containing eggs are formed
and produced and will eventually become the
fruit.

23.  the structures in the chamber of an ovary
containing the egg cell, within the embryo sac.
FUNCTION:
Carries female gametes and become seeds after
fertilization.

25.  The peduncle is a stem, usually green, though
some peduncles are more or less florally
colored or neutral in color, having no
particular pigmentation.
FUNCTION:
The main function of peduncle is to support
inflorescence.

27.  The thickened part of a stem from which
the flower organs grow.
FUNCTION:
The receptacle gives rise to the edible part of
the flower and fruit.

29.  Calyx, the collective name for sepals of a
flower. They are often green and hairy.
FUNCTION:
The calyx serves as a protective covering for the
flower bud helping to protect it from insect
damage and prevent it from drying out.

31.  Collective term for all the petals of a flower.
They are often brightly colored and scented.
FUNCTION:
To attract insects for pollination, and act as
landing pad.

34.  Variations in
flower structures..

35.  Flower with all four whorls of floral leaves.
example: hibiscus or gumamela

36.  Flower with one or more whorls of floral
leaves missing.
Example: squash and rue anemone

37.  A perfect flower has both stamens and
carpels, and may be described as "bisexual" or
"hermaphroditic".
Example: lily, sacred garlic pear

38.  A "unisexual" flower is one in which either the
stamens or the carpels are missing, vestigial or
otherwise non-functional.
A. Staminate- having only functional stamens
and thus male.
Example: kiwi

39. B. Pistillate- having only functional pistil and
thus female.
Example: melon

40. C. Monoecious- staminate and pistillate flowers
on the same plant.
Example: petunias

41. D. Dioecious- staminate and pistillate flower on
different plants.
Example: holly

42.  Flowers with all their flower parts are the
same in size and shape.
Example: buttercup

43.  Flowers with different shape and size flower
parts.
Example: orchid

44.  is the union of unlike parts; organically united
or fused with another dissimilar part.
Example:
primrose

45.  The fusion of similar organs.
Example:
Gumamela

47.  The collective cluster of flowers.
 Some inflorescences are composed of many
small flowers arranged in a formation that
resembles a single flower.
 An inflorescence may include specialized
stems and modified leaves known as bracts.

48.  Single - When all the flowers are gathered in
the same single pattern.
MAIN SINGLE INFLORESCENCES:
Racemes- In racemes, florets are attached
along a floral peduncle with stems similar in
length. Young florets appear above and the
old ones below.

50.  A spike is a raceme, but the flowers develop
directly from the stem and are not borne on
pedicels, as in barley (Hordeum).

51.  A spadix is a spike of flowers densely arranged
around it, enclosed or accompanied by a
highly specialized bract called a spathe. It is
characteristic of the Araceae family.

52.  a flower cluster whose lower stalks are
proportionally longer so that the flowers form
a flat or slightly convex head.

53.  An umbel is an inflorescence which consists of
a number of short flower stalks
(called pedicels) which spread from a common
point, somewhat like umbrella ribs. The
arrangement can vary from being flat topped
to almost spherical. Umbels can be simple or
compound. The secondary umbels of
compound umbels are known as umbellules.

56.  A head (capitulum) is a short dense spike in
which the flowers are borne directly on a
broad, flat peduncle, giving the inflorescence
the appearance of a single flower.

58.  Elongated cluster of single-sex flowers bearing
scaly bracts and usually lacking petals.

59.  Compound inflorescences is when a complex
pattern is made of another single pattern.
MAIN COMPOUND INFLORESCENCES:
Compound Umbels- Are formed by several
umbels gathered together.

61.  Panicles are formed by several racemes
gathered together.

62.  is defined as the ensemble of fruits derived
from the ovaries of an inflorescence. It usually
retains the size and structure of the
inflorescence.

64.  Pollen formation occurs in the anthers,
the club-shaped structures that rest on
top of the numerous filaments that
emerge from the center of a flower.
These anthers contain structures
called microsporangia that generate
pollen. These microsporangia undergo
meiosis, producing microspore cells
that contain half of the normal amount
of genetic material. Each microspore,
in turn, reproduces itself several times
to form a pollen grain. A single pollen
grain contains two sperm cells and a
cell that will grow into a tube that
allows the sperm to pass into the
ovule during pollination.

66.  A similar process takes place in
the ovary of the flower, which is
located at the flower's base. The
megasporangia in the ovary
undergo meiosis, resulting in
megaspores, each of which will
develop into an ovule. The
megaspore divides multiple times
to form the structures found
inside the ovule. An embryo sac,
synergid cells that attract the
pollen tube, cells that become a
food source for the embryo, and
the egg cell form from the
megaspore cell. Following
pollination and fertilization, each
ovule becomes a seed.

67.  Is the process of transferring pollen grains
from the anther to the stigma. It is
accomplished by wind, water or animals.

68.  If a stigma receives pollen from the same
flower on the same plant, it is self-pollinated.

69.  If the stigma receives pollen from another
flower of the same species, the flower is
cross-pollinated.

70. The fusion of gametes, results in
diploid zygotes, which divide by
mitosis and form new
sporophytes.

71.  The fusion of male and female
gametes (sex cells) produced by the
same plant. Self-fertilization occurs
in bisexual organisms.
Example: gumamela

72.  The process by which two sperm cell
nuclei unite with two cell nuclei of
the female gametophyte. The
triploid nucleus will divide many
times, eventually forming the
endosperm of the seed.

74.  - The response of flowering plants to the
difference in the duration of light and dark
periods in a day. Plants can be placed into
three categories, depending on the day length
they require for flower production.
 Short day plants (example: strawberries,
golden rod flower, crysanthemum)
 Long day plants (example: spinach, lettuce)
 Neutral (example: cucumber, tomatoes, corn)

75.  Biology: The dynamics of Life/Texas edition/ Biggs,
Kapicka, Lundgren
 Botany: Introduction to Plants/ Weier, Stocking,
Barbour, Rost
 Biological Science/9th edition/ Campbell
 Biology: Concepts and Connections/6th edition/
Campbell
 Plant systematics/3rd edition/ Gucharan Singh
 www. Wikipedia.com/pictures
 www.Botanical-online.com

76. What is the largest flower in the World?
 The largest flower in the world is the Rafflesia
arnoldi. It weighs approximately 7kgs and its
petals grow to a meter long and 2.5cmss
thick. This flower grows on the Sumatra
Island of Indonesia.
 Also known as the ‘corpse flower' as it emits a
foul odor and attracts flies for pollination.

77.  Top 5 most popular flowers in the World
 1. Rose
 2. Carnation
 3. Chrysanthemum
 4. Tulip
 5. Gerbera

78. Thank you!
FAULET GALE B. ENRIQUEZ
BSE-BIOLOGICAL SCIENCE
2nd yr./block 3
Dr. Annie Cu Gallardo