Module 1 FINALS: PHBotany LAB

Pollination

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

1. Pollen grains from the respective flowers land on the stigma
2. Formation of pollen tube with the style length, which connects both the stigma and ovary.
3. Pollen grain starts transmitting sperm cells from the grain to the ovary.
4. Formation of seed and release of seed.

Fertilization

The fusion of male gamete with female gamete.

Process of fertilization

1. A pollen grain is transferred from one flower to another. A pollen tube grows from the stigma to the ovary.
2. The nucleus of the pollen passes through the pollen tube and joins with the egg cell inside an ovule in the ovary.
3. 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