POLLINATION Flashcards
Both male and female gametes are motile.
true/false
false
both non-motile
Transfer of pollen grain ( shed from filament) to style of pistil is termed pollination.
true/false
false
shed from anther to stigma
Flowering plants use internal agents for pollination.
True/false
False
external
Depending on ____ there are 3 types of pollination
source of pollen
Transfer of pollen grains from anther to stigma of same flower is autogamy.
True/false
True
In flowers which open and expose their anther and stigma, autogamy is common.
true/false
False
rare
Conditions for autogamy in open/exposed flowers.
2
- Synchrony in pollen release and stigma
2.Anther and stigma should lie close to each other
Examples of plants with both chasmogamous and cleistogamous flowers.
- Viola(common pansy)
2.Oxalis
3.Commelina
Chasmogamous flowers have ________ anther and stigma
exposed/close
Exposed
Cleistogamous flowers do not open at all.
True/false
True
In cleistogamous flowers, anther and stigma lie close/far from each other.
Close
When anthers dehisce in floral buds in cleistogamous flowers, pollen grains come in contact with the stigma of same flower to effect pollination.
True/false
True
Cleistogamous flowers are invariably autogamous.
True/false
True
There is a 10 percent chance of cross-pollen landing on stigma of cleistogamous flowers.
true/false
False
no chance
Which type of flowers produce assured seed-set even in the absence of pollinators?
Cleistogamous flowers
Transfer of pollen grains from anther to stigma of another flower of the same plant is called________
Geitonogamy
Geitonogamy is functionally cross/self pollination.
Cross
Geitonogamy involves pollinating agent.
True/false
True
Genetically , geitonogamy is similar to autogamy as the pollen grains come from the same plant.
True/false
True
Transfer of pollen grains from anther to stigma of a different plant is called
Xenogamy
Genetically different types of pollen grains are brought to stigma by _______
auto/geitono/xeno
Xenogamy
How many kinds of biotic agents do plants use for pollination and what is the name?
1,Animals
Majority of plants use abiotic/biotic agents for pollination.
Biotic
Pollen grains coming in contact with stigma is assured in wind and water pollination.
True or false
False
Chance factor
How do flowers compensate for the loss of pollen grains?
They produce enormous amount of pollen grains when compared to the number of ovules available for pollination.
Among abiotic pollinations,
which one is more common?
wind/water
wind
To transport pollen grains by wind currents, what are the characteristics of pollen grains req.?
2
Light, non-sticky
What chars. of stigma and stamen are req. for wind pollination?
stamen - well exposed (easy dispersion)
stigma - large, feathery ( trap air-borne pollen grains)
Wind pollinated flowers have how many ovules in the ovary ?
one
Wind pollinated flowers have numerous flowers packed into an inflorescence.
True/false
True
Tassels of corn cob are ________ and ____ which wave in wind to trap pollen grains
Stigma and styles
Wind pollination is rare in grasses
true/false
False
common
Pollination by water is rare/common in flowering plants limited to 30/450 genera, mostly dicots/monocots.
Rare,30,monocots
Why is water req. in lower plant groups like algae, pteridophytes, bryophytes?
for the the transport of male gamete
Examples of water pollinated plants that grow in fresh water
Vallisneria, Hydrilla
Marine sea-grasses such as ____ are examples of water pollinated plants.
Zostera
All aquatic plants use water pollination.
True/false
False
Examples of plants in which flowers emerge above the water level and use insects, wind for pollination
Water hyacinth, water lily
How do the female flowers of Vallisneria reach the surface of water?
using Long stalk
In Vallisneria, the male flowers are situated on the surface of water and release pollen grains under water.
True/false
False
pollen grains also released on to the surface of water
Pollen grains are carried actively/passively by water currents in Vallisneria.
passively
In sea-grasses ,female flowers are already above the surface of water.
true/false
False
submerged in water
In sea- grasses, pollen grains are released inside water.
true/false
True
In sea-grasses, pollen grains’ characters are________
Long,ribbon like
In sea-grasses, pollen grains are carried actively/passively inside water.
passively
How are pollen grains protected from wetting in water pollinated species?
By a mucilaginous covering.
Wind and water pollinated flowers are colourful/not colourful and produce/do not produce nectar.
not colourful, do not produce nectar
What 2 kinds of birds are used for pollination?
Sunbird and humming birds
Dominant biotic pollinating agents are
Bees
List 3 larger animals that have been reported to pollinate some species.
- Primates(lemur)
- Arboreal rodents ( tree-dwelling rodents)
- Reptiles(garden lizards and gecko lizards)
Often flowers get specifically adapted to pollination by a particular species of animals.
True/false
True
List 4 chars. of majority of Insect pollinated flowers
- Large
- Colourful
- Fragrant
- Rich in nectar
What do small insect pollinated flowers do ?
No. of flowers get clustered into an inflorescence to make them conspicuous.
Flowers pollinated by ____ and ____ secrete foul odours to attract them.
Flies and beetles
What are the 2 usual floral rewards?
Pollen grains, nectars
For harvesting floral rewards, the animal has to come in contact with ____ and ____
Anther, stigma
Pollen grains of animal pollinated flowers are non-sticky.
True/false
False
sticky
In tallest flower of 6 feet height called________ , floral reward is ___________
Amporphophallus, safe place for laying eggs
A species of moth and Yucca plant can’t complete their life cycle without each other.
True/false
True
Moth deposits its eggs in the ____ of Yucca plant
Locule of the ovary
When do the larvae of moth come out of the eggs?
When seeds start developing
Insects that consume pollen/nectar without bringing about pollination are called ______
pollen/nectar robbers
Majority of flowering plants produce ____ flowers
Hermaphrodite(bisexual)
Hermaphrodite flowers increase chance of self/cross pollination.
Self
Continued self pollination results in ____________
Inbreeding depression(genetic diversity loss)
Devices used to discourage self pollination and encourage cross pollination are called _________
Outbreeding devices
To reduce self-pollination , stigma receptivity and pollen release are not synchronized.
True/false
True
Anther and stigma are placed at same positions to reduce self-pollination.
True/false
False
Different
Self pollen refers to
Pollen from same flower and other flowers of same plant
Self incompatibility is a ____ mechanism that prevents self pollen from fertilising ovules by inhibiting ____ or ____ in pistil.
Genetic, pollen germination, pollen tube growth
Production of unisexual flowers is a device to prevent self-pollination.
True/false
True
Monoecious means
Both male and female flowers on same plant but only unisexual flowers.
Monoecious plants prevent autogamy/geitonogamy
Only autogamy
Examples of monoecious plants
Castor, maize
Dioecious means
Only one kind of unisexual flower ( male or female) present on one plant - plant is either male or female(dioecy)
Dioecy prevents autogamy/geitonogamy
Both
Example of dioecious plants
Papaya, date palm
