XII: Chapter 2- Sexual reproduction in flowering plants Flashcards
In a flower, what is the proximal end o fthe filament attached to?
Thalamus or petal
How many wall layers surround the microsporangium of an anther? Name them.
4- Epidermis, endothecium, middle layers and tapetum
Which layers of microsporangium help in dehiscence of anther?
Epidermis, endothecium and middle layers
Which cells are also known as pollen mother cell?
Cells of sporogenous tissue
What represent the male gametophyte in angiosperms?
Pollen grain
What is the diameter of a typical pollen grain?
25-50 μm
What is the shape of generative cell of a pollen grain?
Spindle shaped
How long does the viability of pollen grains last in cereals?
30 minutes
What is the cavity of ovary called?
Locule
Where is the placenta located in a flower?
Inside locule
What are the megasporangia of flower?
Ovules
How many ovules are found per ovary in wheat?
One
What is the stalk through which the ovule in plants attaches to the placenta called?
Funicle
Which is the basal part of the ovule?
Chalaza
The female gametophyte of angiosperm is represented by
Embryo sac
Where is the megaspore mother cell present in an ovule?
In the micropylar region of nucellus
How many megaspore mother cells generally differentiate in an ovule?
One
What is meant by monosporic development?
Three of the four megaspores formed from megaspore mother cell in an ovule degenrate, and only one functional megaspore develops into female gametophyte. This is known as monosporic development.
The flowers of plants that never open are called
Cleistogamous flowers
How many plant genera show water pollination?
30
Where does the moth deposit its eggs in the Yucca plant?
In the locule of the ovary
Is castor monoecious or dioecious?
Monoecious
Pollen-pistil interaction refers to which event?
Events from deposition of pollen on the stigma to the entry of pollen tube into the ovule
At which end of the ovule does the embryo develop?
Micropylar end
Arrange the following in the order of development:
Heart-shaped embryo, proembryo, mature embryo, globular embryo
Proembryo
Globular embryo
Heart-shaped embryo
Mature embryo
Where is the root cap present in a dicot embryo?
Over the root tip
WHat is the root tip of dicot embryo called?
Radicle
What does the epicotyl of monocot embryo contain?
Shoot apex, leaf primordia, coleoptile
WHat is the fertilised ovule of plants called?
Seed
Is perisperm found in beet?
Yes
What is the percentage of moisture by mass of a dormant seed?
10-15%
The oldest recorded viable seed belongs to the plant
Lupinus arcticus
Apomixis is common in which plant family?
Asteraceae and families of grasses
What is amphimixis?
Sexual reproduction involving the fusion of two different gametes to form a zygote.
WHat is microsporophyll in angiosperms?
Stamen
Monothecous stamen is found in which family of plants?
Family Malvaceae
What do the inner walls of endothecium of microsporangium have?
α- cellulosic fibres
What do the radial walls of endothecium have?
Callose bands
How many layers are present in middle layers of microsporangium of plants?
1-3
What type of cells are present in middle layers of microsporangium of plants?
Parenchymatous cells
Which layer of microsporangium is ephemeral in nature?
Middle layers
Which wall layer is present in immature anther but not in mature anther?
Middle layers
What are the places where α- cellulosic fibres are absent in endothecium of microsporangium called?
Stomium
What is the significance of stomium?
These are the places where dehiscence of anther occurs
What is the significance of α- cellulosic fibres in endothecium of microsporangium ?
It makes the endothecium hygroscopic which leads to absorption of moisture and bursting of anther.
Which layer of microsporangium forms sporopollenin and pollen kit?
Tapetum
Which type of tapetum leads to the degeneration of middle layers because of absorption of all its food?
Amoeboid tapetum
Which type of tapetum formes proeubisch bodies?
Glandular tapetum
How are proeubisch bodies converted into eubisch bodies?
Proeubisch bodies are covered in sporopollenin to form eubisch bodies.
Where does the glandular tapetum release the eubisch bodies?
Inside the pollen chamber
Which substance attaches the microspores in a microspore tetrad together?
Callose
How does the callose layer of microspore tetrad dissolve?
By the callase enzyme secreted by tapetum
What type of microspore tetrad is found in monocots?
Tetrahedral
What type of microspore tetrad is found in most dicots?
Isobilateral
Name the different types of microspore tetrads?
Tetrahedral, isobilateral, decussate, t-shaped and linear
What is the exine of pollen grain made of?
Cutin and sporopollenin
Which layer of pollen grain forms the pollen tube?
Intine
What is the study of pollen grains called?
Palynology
What kind of development- ex-situ or in-situ is found in pollen grains?
In-situ development
[Pollen grains develop in pollen grains, that is in-situ]
What is the fertilisation in which pollen tube is formed called?
Siphonogamy
WHich plant has the longest pollen tube?
Maize
What is the pollen kit composed of?
Lipids and carotenoids
What is the colour of pollen kit?
Yellow
The generative cell of pollen grain has a large nucleus. True/false?
False
The vegetative cell has a large nucleus while the generative cell has a small nucleus.
Pollinium is found in which family of plants?
Asclepiadaceae (eg- calotropis)
When all the pollen grains join together as in calotropis, what is the structure formed called?
Pollinium/translator apparatus
Hay fever is caused by
Ambrosia
Largest pollen grains belong to the plant
Mirabilis jalapa
Smallest pollen grain is found in the plant
Myocystis
Longest pollen grain is found in
Zostera
Hilum fuses with the main body of ovule to form
Raphe
What type of cells are present in nucellus of ovule?
Parenchymatous
What forms funicle and integuments of ovule?
Chalaza
What is the proliferation of the integumentary cells at the micropylar region in castor called?
Caruncle
How many integuments are found in the ovule of Santalum?
Zero
How many integuments are found in gamopetalae?
One
How many integuments are found in sunflower?
One
How many integuments are found in polypetalae?
Two
How developed is the nucellus of gamopetalae?
Poorly developed (tenuninucellate)
How developed is the nucellus of polypetalae?
Well developed (crassinucellate)
How developed is the nucellus of most monocots?
Well developed (crassinucellate)
In which type of ovule does the micropyle, chalaza and funicle lie in a straight line?
Orthotropous
Which type of ovule is found in most gymnosperms (on the basis of orientation)?
Orthotropous
Which is the most primitive type of ovule on the basis of orientation?
Orthotropous
Which type of ovule is found in polygonum (on the basis of orientation)?
Orthotropous
Which type of ovule rotates by an angle of 180° and bends along the funicle?
Anatropous
In which type of ovule does the micropyle lie close to the hilum?
Anatropous
Which type of ovule (on the basis of orientation) is found in legumes?
Anatropous
Which type of ovule curves more or less at a right angle?
Campylotropous
Which type of ovule (on the basis of orientation) is found in brassica?
Campylotropous
Which type of ovule turns at a right angle along the funicle?
Hemianatropous
Which type of ovule (on the basis of orientation) is found in Ranunculus?
Hemianatropous
In which type of ovule is the curvature of the ovule extremely pronounced and the embryo sac also becomes curved?
Amphitropous
Which type of ovule (on the basis of orientation) is found in Mirabilis jalapa?
Amphitropous
Which type of ovule turns 360° along the funicle?
Circinotropous
Which type of ovule (on the basis of orientation) is found in Euphorbia?
Circinotropous
The nucellus of ovule develops from
Placenta
Which is the first cell of female gametophyte?
Functional megaspore
When do the polar nuclei form the secondary nucleus?
When the pollen tube touches the embryo sac
Filiform apparatus is present in antipodal cells. True/false?
True
But it is non functional
What type of embryo sac is found in oenothera?
4 celles and 4 nucleate
What are the cells found in embryo sac of oenothera?
Egg apparatus and 1 polar nucleus
What is monocliny?
Presence of both male and female sex organs in a flower
What is homogamy?
Maturation of male and female sex organs at the same time
Potato is dichogamous. True/false?
False.
Potato is homogamous.
What is dichogamy?
Maturation of male and female sex organs at different times.
What is protandry in flowers?
Maturation of male sex organ before female sex organ
What is prepotency?
On the stigma, pollen grains of other plants (of same species) mature faster than pollen grains same plant
What is herkogamy?
Mechanical device which prevents self pollination
What is heterostyly?
Vast difference between length of style of carpel and filament of anther.
What is pollination by bats called?
Chireptoerophily
What is pollination by snakes called?
Ophiophily
What type of pollination if found in Cannabis?
Anemophily
What type of pollination is found in potamogeton?
Anemophily
What type of pollination is found in coconut and dates?
Anemophily
What type of pollination is found in bamboo and sugarcane?
Anemophily
Is anemophily a directional process?
No
In which type of pollination, pollen grains have specific gravity lower than water?
Hydrophily
In which type of pollination is the size of flowers and number of nectar glands maximum?
Ornithophily
Adansonia is pollinated by
Bats
Polysiphony is found in which family of plants?
Family malvaceae and family cucurbitaceae
What type of movement is shown by pollen tube?
Chemotropic movement
Where does the pollen tube enter the embryo sac in Betula and walnut?
Chalaza
Where does the pollen tube enter the embryo sac in cucurbits?
Integuments
Where does the pollen tube release the nuclei in embryo sac?
Cytoplasm of central cell
When does the vegetative nucleus of pollen grain degenerate?
When the pollen tube touches the embryo sac
How many nuclei are involved in double fertlization?
5 (2 nuclei of pollen grain, 1 nucleus of egg cell, 2 pollen nuclei)
What is the ploidy of endosperm in gymnosperms?
Haploid
What does the funicle form after fertilization in plants?
Stalk of seed
Testa of seed is formed from
Outer integument
Tegment of seed is formed from
Inner integument
Who is the father of Indian (plant) embryology?
P. Maheshwari
What type of fission is the first division in embryogenesis in dicot plants?
Transverse fission
Which cells are formed as a result of transverse fission in zygote in dicots?
Small apical cell and large basal cell
What does the apical cell in the two celled stage of dicot plant embryogenesis form in future?
Hypocotyl, shoot apical meristem, and cotyledons
What does the basal cell in the two celled stage of dicot plant embryogenesis form in future?
Hypophysis and suspensor
What type of divisions take place in two celled stage to form eight celled stage in embryogenesis in dicots?
Two rounds of longitudinal division, and one round of transverse division
What does the hypophysis of dicot embryo form?
Root cap
What is the function of suspensor in dicot embryo?
Absorbs food from endosperm through haustorial cell and transfers it to the embryo
What do the epibasal cells in octant stage of dicot embryo form in future?
Cotyledons and plumule
What do the hypobasal cells in octant stage of dicot embryo form in future?
Radicle and hypocotyl
Towards which side of embryonal axis is the sclutellum situated in monocot embryo?
Lateral side
What does the epiblast represent in a monocot embryo?
Rudiments of second cotyledon
In which seeds are the cotyledons thin and papery?
Albuminous/endospermic seeds
Can perisperm develop in endospermic seeds?
No
What is the type of germination in which cotyledons are pushed out of the soil by fast growth of hypocotyl called?
Epigeal germination
What is the type of germination in which cotyledons remain in the soil by fast growth of epicotyl called?
Hypogeal germination
What type of germination (hypogeal or epigeal) is found in most monocots?
Hypogeal germination
What type of germination (hypogeal or epigeal) is found in castor?
Epigeal germination
What type of germination (hypogeal or epigeal) is found in beans?
Epigeal germination
Is polyembryony commonly found in gymnosperms or angiosperms?
Gymnosperms
What is pseudopolyembryony?
Many embryos are formed from more than one embryo sac in an ovule
What is true polyembryony?
Many embryos are formed from a single embryo sac.
What is the ploidy of oosphere?
Haploid
[oosphere= egg]
How many stamens are present in the flower of crotolaria?
10
