Studied by 3 peoplePollination
The act of transferring pollen grains from the male anther of a flower to the female stigma.
Pollination
The process in which pollen is taken from one plant or part of a plant to another so that new plant seeds can be produced.
Pollination
It leads to the creation of new seeds that grow into new plants
Anther
part of a flower that contain the pollen
Stigma
it receives the pollen grains
Making seeds
One of the ways that plants can produce offspring is by
create offspring
The goal of every living organism, including plants, is to ______ for the next generation.
Pollen
is the contribution of the male parent and the female parent provides the ovule.
Ovule
The female parent provides what?
Pollination process
involves the transfer of pollen from the male part of a plant (in flowers, this is the ‘stamen’) to the female part of the plant (the 'carpel').
Stamen
Male part of flowers
Carpel
Female part of flowers
Male sperm
The pollen contains male?
carpel
Where the female gametes are contained
male part of the flower
comprising the anther and filament (together, they are called the ‘stamen’)
female part of the flower
the stigma and style with the ovary (containing the ovule) at the base of the flower (called the ‘carpel').
Plant Pollination Process
Pollen grains from the respective flowers land on the stigma
Formation of pollen tube with the style length, which connects both the stigma and ovary.
Pollen grain starts transmitting sperm cells from the grain to the ovary.
Formation of seed and release of seed.
Fertilization
The fusion of male gamete with female gamete.
Process of fertilization
A pollen grain is transferred from one flower to another. A pollen tube grows from the stigma to the ovary.
The nucleus of the pollen passes through the pollen tube and joins with the egg cell inside an ovule in the ovary.
The fertilized egg cell develops into an embryo.
Pollination
is the prerequisite of Fertilization.
Fertilization
it cannot occur without pollination and pollination will be useless if it will not take place.
pollination agents or pollinators
external factors needed for pollination
Fertilization process
only the pollen grains and the flower’s reproductive system are needed to make it work.
Fertilization
can only occur after a successful Pollination.
Pollination
It will be useless if fertilization will not take place.
Angiosperm
are a major division of plant life, which make up the majority (80%) of all plants on Earth.
Angiosperm
are also known as “flowering plants” because flowers are a characteristic part of their reproductive structure – though again, you may not always recognize their flowers as the pretty, colorful petaled things.
Angiosperm
plants produce seeds encased in “fruits,” which include the fruits that you eat, but which also includes plants you might not think of as fruits, such as maple seeds, acorns, beans, wheat, rice, and corn.
Gymnosperms
Develop their seeds on the surface of scales and leaves, which often grow to form cone or stalk shapes
Gymnosperms
Woody, vascular plants with seeds but without flowers or fruits
Seeds of Gymnosperms plants
sit exposed on cones rather than enclosed in a fruit as they are with angiosperm plants.
gymnos
Means naked in greek
Sperma
Means seed in greek
gymnosperms
were for a long time the dominant plants on Earth but have been overthrown since the evolution and diversification of the angiosperms
Conifers
still dominate in cold and dry environments, as a waxy covering (cuticle) on their needle-like leaves allows them to survive in more extreme conditions than the angiosperms
Pine trees
tend to become more common towards the poles and at higher elevations where temperatures become colder.
Coniferophyta, Cycadophyta (saycadofita), Ginkgophyta, Gnetophyta.
Gymnosperms are classified into 4 divisions
1,000 species
Species of gymnosperm
Angiosperms
number over 260,000 species
monocots that have a single cotyledon
dicots (also called eudicots or true dicots) with two cotyledons; trees, herbs, and shrubs
Angiosperm are divided into
Dicots
also called eudicots or true dicots)
Abiotic
By wind and by water
Biotic
By animals or insects
10%
Among plants, only ____ does not require pollinators.
Abiotic pollination
does not require the assistance of any other organism but instead relies on environmental components such as wind and water.
grasses, coniferous and some deciduous trees, and aquatic plant species.
Some plants that commonly use Abiotic pollinations are
Biotic pollination
is much more common and involves the participation of other organisms to distribute pollen
Pollinators
often maintain a very close relationship with the plants that pollinate.
petals of plants
often brightly colored and the flowers themselves are fragrant and produce sweet nectar, all of which attract animals to the plant and encourage pollination.
Self-Pollination or Autogamy
If the pollen grains are transferred from an anther to the stigma of the same flower, or different flowers of the same plant.
Self-Pollination or Autogamy
This type of pollination is observed in about 1⁄4 of the plants
Self-Pollination or Autogamy
Referred to as the primary type of pollination as it includes a single flower.
Self-Pollination or Autogamy
Occurs when pollen grains fall directly from anther into the stigma of the flower.
Simple and fast type of pollination
Self-Pollination or Autogamy
Reduction in genetic diversity as the sperm and egg cells of the flower share some genetic information.
Self-Pollination or Autogamy
It often results in homozygous plant lines, or plants with identical gene pairs for many traits, which ensures new plants grown from saving seed will be almost identical to the parent plants. Beans and peas are two examples of self-pollinated plants in the home vegetable garden.
Monocliny (Bisexuality)
Presence of male and female organs in the same flower.
bisexual
The presence of bisexual flowers is a must for self pollination._
hermaphrodite
All the self pollinated plants have ______flowers.
Homogamy
Both sex organs of a flower mature at the same time. Maturation of anthers and stigma of a flower at the same time is called ____ . As a rule, it is essential for self-pollination.
Cleistogamy
Pollination and fertilization occur in unopened flower bud. When pollination and fertilization occur in unopened flower bud, it is known as ____.
Cleistogamy
It ensures self pollination and prevents cross pollination.
Cleistogamy
has been reported in some varieties of wheat, barley, oats and several other grass species.
Chasmogamy
Opening (blooming) flowers only after the completion of pollination.
Opening of flowers only after the completion of pollination is known as ___ .
Chasmogamy
This also promotes self pollination and is found in crops like wheat, barley, rice and oats.
Position of Anthers
Stigmas are surrounded by anthers (e.g. soybean, chickpea, pea).
Such situation is found in tomato and brinjal.
Position of Anthers
Examples are greengram, blackgram, soybean, chickpea and pea.
stamens and stigma
In some legumes, _____ are enclosed by the petals in such a way that self pollination is ensured.
stigma
In some species, ____ are surrounded by anthers in such a way that self pollination is ensured.
Self-Pollination: Advantages
Ensures that recessive characters are eliminated. • Wastage of the pollen grain is very less compared to cross-pollination • Purity of the race is maintained, as there is no diversity in the genes No involvement of external factors like wind, water, and other pollinating agents. • Ensures that even a smaller quantity of produced pollen grains from plants have a good success rate in pollination.
Self-Pollination: Disadvantages
No mixing up of genes. Due to which: –The vigour and vitality of the race are reduced –The immunity to diseases is reduced in the resultant offsprings.
Cross-Pollination or Allogamy
When the pollen grains are transferred to the stigma of other flower of the same species. It takes place in between two different flowers.
Cross-Pollination or Allogamy
the pollen from the anthers of a certain plant is transported to the pistil (stigma) of another plant.
The — provides greater genetic diversity and hence more vital offspring, compared to the self pollination.
Cross-Pollination or Allogamy
It occurs in the most of the flowering plants (in about 3⁄4 of the species)
Cross-Pollination
Refers to a complex type of pollination that allows the transfer of pollen grains from the anther of the flower into the stigma of another flower.
Cross-Pollination
Leads to an increase in genetic diversity as different flowers will share and combine their genetic information to create unique offspring.
By insects
the process takes place in several plants like tulips, grapes, plums, apples, pears, strawberries, daffodils, raspberries and others.
by wind
for different grasses, maple trees, dandelions, catkins, and others.
Cross-pollination
occurs when pollen from one plant fertilizes the ovules of another plant. Some plants cannot set viable seed without cross pollination, as is the case with broccoli and many apple cultivars.
Cross-pollination
happens through the actions of pollinators, such as insects and other animals, or by wind blowing pollen from plant to plant.
cross-pollinated by insects; wind pollinated
In the home vegetable garden, tomato, watermelon and cucumbers are ___ and sweet corn is ______.
Geitonogamy
Pollination takes place in between the two flowers of the same plant; Genetical point of view, it is self-pollination but ecologically, considered as cross-pollination.
Xenogamy
Pollination takes place in between flowers of two different plants of the same species; It is real or true cross-pollination, genetically and ecologically.
Dicliny (Unisexuality)
Presence of unisexual flowers confirms cross-pollination is compulsory in this mechanism promoting cross-pollination
Monoecy
same plant (e.g. mango, castor, banana)
Dioecy
different plant (e.g. papaya, spinach, asparagus)
Monoecy
When male and female flowers are separate but present in the same plants, it is known as
mango, castor and banana
In some crops, the male and female flowers are present in the same inflorescence such as in ____. In some cases, they are on separate inflorescence as in maize.
Dioecy
When staminate and pistillate flowers are present on different plants, it is called dioecy. It includes papaya, date palm, spinach, hemp and asparagus
Inflorescence
complete flower head of a plant (stems, stalks, bracts, and flowers)
Dichogamy
From the Greek dikho-apart and gamousmarriage.
Dichogamy
It refers to maturation of anthers and stigma of the same flowers at different times.
____ promotes cross pollination even in the hermaphrodite species.
Anthers and stigma
do not mature at the same time
protogyny
When pistil matures before anthers,
protandry
When anthers mature before pistil, it is known as ___ It is found in maize, sugarbeet and several other species.
Heterostyly
When styles and filaments in a flower are of different lengths, it is called _____.
Difference between the length of the filaments of stamens and length of the style (e.g. linseed)
Heterostyly
It promotes cross pollination, such as linseed.
Herkogamy
Hindrance to self-pollination due to some physical barriers such as presence of hyaline membrane around the anther is known as _____.
Hyaline membrane
Such membrane does not allow the dehiscence of pollen and prevents self-pollination such as in alfalfa.
Dehiscence
splitting or bursting open of a pod
Note
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