sexual reproduction in flowering plants. Flashcards
Female reproductive part of the flower ?
Gynoecium
Female reproductive part of the flower ?
Gynoecium
Single pistil - __________
More than one pistil - _________
More than one pistil that are fused -________
Pistils that are free-_______
- Monocarpellary
- Multicarpellary
- Syncarpous
- Apocarpous
________ are morphological and embryological marvels and are the sites of ______ reproduction.
Flowers , sexual
Several ______ and ______ changes are initiated which lead to the differentiation and further development of the _______ ______
Hormonal , structural, floral primordium
_____ are formed which bear the floral bud and then the flowers .
Inflorescence
Two parts of stamen
Anther and filament
Stamen has a long slender stalk called _____ and terminal generally ___ lobed structure called ____
Filament , bi , anther
- The proximal end of the filament is attached to ____ or ____
- A typical angiospermic anther is bilobed , each lobe having ___ Theca.
- They are _______. ( based on having two thecas)
- Often a longitudinal groove runs lengthwise separating the _____.
- Thalamus or petal
- 2
- Dithecous
- Theca
- Anther is a four sided structure (_______) consisting of _____ microsporangia located at the ______ , _____ in each lobe .
Tetragonal , 4 , corners , 2
The microsporangia develop further and become _______.
They extend _________ all through the length of an anther and are packed with ________.
Pollen sacs , longitudinally , pollen grains
A typical microsporangium appears______ in structure .
It is surrounded by ____ wall layers .
Name of the layers -
Circular
4
1. Epidermis
2. Endothecium
3. Middle layer
4. Tapetum
- Epidermis , endothecium and middle layer perform the function of ______ and ______.
- The innermost wall layer is called ____
- Function of tapetum .
- Cells of the tapetum posses dense ______ and generally have more than ______ nucleus .
- Protection and dehiscence of anther
- Tapetum
- Nourishes the developing pollen grains .
- Cytoplasm , more than one .
- Epidermis , endothecium and middle layer perform the function of ______ and ______.
- The innermost wall layer is called ____
- Function of tapetum .
- Cells of the tapetum posses dense ______ and generally have more than ______ nucleus .
- Protection and dehiscence of anther
- Tapetum
- Nourishes the developing pollen grains .
- Cytoplasm , more than one .
When the anther is young , a group of compactly arranged ________ cells called the ___________ occupies the centre of each _________.
Homogeneous, sporogenous tissue , microsporangium .
As the anther develops, the cells of Sporogenous tissue undergoes ________ divisions to form _________.
Meiotic divisions , microspore tetrads .
True or false
1. Each cell of sporogenous tissue is capable of giving rise to a microspore tetrad .
True
1.Each one of the cells of microspore tetrad is a potential pollen or ________ \ ______
2. MMC is also called as ______
MMC\PMC
Potential pollen
1.The process of formation of microspores from pollen mother cell through meiosis is called _______.
2. The microspores as they are formed are arranged in _____ of ____ cells called as _______.
Microsporogenesis
Cluster of cells , microspore tetrads
True or false
1. As the anthers mature and hydrate , the microspores dissociate from each other and develop into pollen grains .
False , dehydrate
- Pollen grains are released with ______ of anther .
- The pollen grain represents the ______ _____.
- Pollen grains are generally _____. ( shape ) .
- Pollen grains measure about ___ to ___ mm in diameter .
- Dehiscence
- Male gametophyte
3: spherical - 25-50
- Pollen grains are released with ______ of anther .
- The pollen grain represents the ______ _____.
- Pollen grains are generally _____. ( shape ) .
- Pollen grains measure about ___ to ___ mm in diameter .
- Dehiscence
- Male gametophyte
3: spherical - 25-50
- Pollen grain has ____ layered wall .
- Hard , outer layer is called ___ made up of ____.
- One of the most resistant organic material known -
- It can withstand high ____ and ____.
- T/F - no enzyme that degrades sporopollenin is known .
- Double
- Exine , sporopollenin
- Sporopollenin
- Temperature and alkali
- T
Pollen grain exine have prominent apertures called ____ where sporopollenin is absent .
2. Pollen grains are well preserved as fossils because of presence of ______.
Germpores
Sporopollenin
- The _____ exhibits fascinating array of patterns and designs.
- The inner wall of pollen grain is called _____ and is made up of ________ and _______.
- hard and discontinous layer ______
- thin and continous layer ______.
- exine
- intine , cellulose and pectin
- exine
- intine
- the cytoplasm of the pollen grain is surrounded by _____.
- when the pollen grain is mature , it contains ____ cells. name of the cells .
- the ____ cell is bigger and have abundant ____ reserve and a large ____ shaped nucleus.
- plasmamembrane
- 2, vegetative cell and generative cell .
- vegetative , food , irrerularly
1.the ____ cell is small and floats in the cytoplasm of ____ cell.
2. generative cell is ____ shaped and have dense ____ and a _____.
- generative , vegetative
- spindle , cytoplasm , nucleus
- in over _____% of angiosperms , pollen grains are shed at this 2 celled stage .
- in 40% of angiosperms , the ____ cell divides ______to give rise to two _____ ______ and then this pollen grain is shed at 3 celled stage .
- 60
- generative , mitotically , male gametes
Pollen grains of many species cause severe _______ and _________ in some people often leading to chronic respiratory disorders _______ ,________ etc .
- Allergies , bronchial afflictions , asthma bronchitis
- ________ or carrot grass that came into India as a contaminant with imported _________ has become ubiquitous in occurrence and causes_______ ______ .
Parthenium , wheat , pollen allergy
- Pollen grains are rich in ________.
- It has become a fashion in recent years to use _________ as food supplements.
- In western countries large number of pollen products in the form of _____ and _____ are available in the market.
- Nutrients
- Pollen tablets
- Tablets and syrups
Pollen consumption has been claimed to increase the performance of ________ and __________.
Athletes and race horses.
- pollen grains have to land on the ______ before they lose viability if they have to bring about __________.
- The period for which pollen grains remain viable is highly _______ and to some extent depends on the prevailing ______ and _______.
- Stigma , fertilisation
- Variable , temperature and humidity
- In some cereals such as ______ and ______, pollen grains lose viability within ________ of their release.
- some members of ________ , __________ , _________ maintain viability for_________.
- Wheat and rice , 30 minutes
- Leguminosae , solanaceae , rosaceae , upto months
- pollen grains of a large number of species are stored for years in ____________ ( temperature) .
- Such stored pollen can be used for _________ similar to seed banks, in ___________ programmes .
- Liquid nitrogen , -196 C
- Pollen banks , crop breeding programs
- Each pistil has ______ parts .
- the ______ , ______ and ________
- The _______ serves as a landing platform
for polien grains. - The ______ is the elongated slender part beneath the stigma .
- The basal bulged part of the pistil is the _________.
- Three
- Stigma , style , ovary
- Stigma
- Style
- Ovary
- Inside the ovary is the ___________ .
- The _________ is located inside the ovarian cavity.
- Ovarian cavity is also called as _____.
- Ovarian cavity
- Placenta
- Locule
- Arising from the placenta are the______________, commonly called ovules. 2. The number of ovules in an ovary may be one ( examples ) to many ( examples).
1.Megasporangia
2. Wheat , paddy , mango
Watermelon , papaya , orchid
- The ______ is a small structure attached to the placenta by means of a stalk called ______.
- The body of the ovule fuses with funicle in the region called _______ .
- hilum represents the junction between _______ and _______ .
- Each ovule has one or two protective envelopes called __________.
- Integuments encircle the ________ except at the tip where a small opening called the _________ is organised .
- Opposite the micropylar end, is the ___________ representing the _____ part of the ovule .
- Ovule , funicle
- Hilum
- Ovule and funicle
- Integuments
- Nucellus , micropyle
- Chalazal end , basal
- Enclosed within the integuments is a mass of cells called the _______.
- Cells of the nucellus have abundant reserve ___________
- Located in the nucellus is the_________or female gametophyte.
- An ovule generally has a ______ embryo sac formed from a megaspore .
- Nucellus
- Food material
- Ovule
- Single
- The process of formation of megaspores from the megapore mother cell is called____________
- Ovules generally differentiate à single ______________in the micropylar region of the nucellus.
- Megasporogenesis
- Megaspore
Ovule is also called as ______.
Megasporangium
Arrangement of megaspore is linear or tetrad ?
Linear
- The MMC undergoes_______ division.
- Meiosis results in the production of ________Megaspore.
- In majority of flowering plants, only ______megaspore is functional while the other three _________.
- Meiotic
- Four
- One , degenerate
- Only the ___________ develops into the female gametophyte (embryo sac).
2.This method of embryo sac formation from a single megaspore is termed as ___________development.
- Functional megaspore .
- Monosporic
1.Embryo sac is also called as ______.
2. Ploidy of the cells of nucellus ?
- Female gamete
- 2n
1.The nucleus of the functional megapore divides ________ to form______ nuclei which move to the opposite poles, forming the ______________.
2. ______ ( number ) more sequential ( mitosis / meiosis ) ______ nuclear divisions result in the formation of the ____nucleate and later the ____nucleate stages of the embryo sac.
1.mitotically , 2 , 2 nucleate embryosac
2. 2 , mitotic , 4 , 8
- interest to note that these mitotic divisions are strictly __________, that is, nuclear divisions are not followed immediately by _______ formation.
- After the ____nucleate stage, _____are laid down leading to the organisation of the typical female gametophyte or embryo sac.
- Free nuclear , cell wall .
- 8 , cell walls .
- _____of the eight nuclei are surrounded by cell walls and organised into cells.
2.The remaining two nuclei, called _______ are situated below the ______ in the large _____ cell. - There is a characteristic distribution of the cells within the _______
- Three cells are grouped together at the micropylar end and constitute the ________.
5.The egg apparatus, in turn , consists of two ______ and one ______.
- Six
- Polar nuclei , egg apparatus , central
- Embryosac
- Egg apparatus
5.synergids , egg cell
- The _______ have special cellular thickenings at the micropylar tip called ___________which play an important role in
guiding the _________ into the _______. - Three cells are at the chalazal end are called the _________.
- Synergids , filiform apparatus , pollen tube , synergids.
- Antipodal cells
- The large central cell has _____ polar nuclei,
- Thus, a typical angiosperm embryo sac, at maturity is ____ celled and ____ nucleate .
- 2
- 7 celled , 8 nucleated .
- Male gamete -
- Female gamete -
- Both the gametes are motile or non motile ?
- Pollen grain
- Embryo sac
- Transfer of pollen grains (shed from the anther) to the stigma of a pistil is termed as __________.
- Depending on the source of __________ , pollination can be divided into _____ types.
- Pollination .
- Pollen , 3
- In this type, pollination is achieved within the ________flower. ( autogamy )
- Transfer of pollen grains from the ______ to the _____ of the same flower.
- In a normal flower which opens and
exposes the anthers and the stigma, complete autogamy is rather _______.
4.Autogamy in such flowers requires synchrony in ______ release and _______ receptivity .
- Same .
- Anther , stigma
- Rare .
- Pollen , stigma .
Some plants such as _______ , _________ and _______ produce ______ types of flowers . ( name or the flowers )
Viola , oxalis, commelina … 2
Chasmogamous and cleistogamous
- Similar flowers of other species with exposed anther and filament is a _______ type of flower .
- _______ flowers do not open at all .
- In such flowers the anther and stigma lie _____ to each other .
- Chasmogamous
- Cleistogamous
- Close
- ________ flowers are invariably Autogamous as there is no chance of cross pollination.
- Cleistogamous
Cleistogamous flowers produce assured _________ even in the absence of ________.
- Seed set , pollinating agent
Common name of viola
Common pansy
Transfer of pollen grains from the anther to the stigma of another flower of the same plant is called ______.
- Geitonogamy
- Geitonogamy is functionally ___________ involving pollinating agent .
- Genetically it is similar to ______ since the pollen grains come from the same plant .
- Cross pollination
- Autogamy
Transfer of pollen grains from anther to stigma of different plant is called _________.
Xenogamy
Type of pollination which brings genetically different types of pollen grains to the stigma ?
Xenogamy
