Sexual Reproduction in Flowering Plants
Exam Duration: 45 Mins Total Questions : 30
The sequence of the four wall layers of micro sporangium from outside is
- (a)
endothecium \(\rightarrow \) epidermis\(\rightarrow \) middle layers \(\rightarrow \)tapetum
- (b)
epidermis\(\rightarrow \)endothecium \(\rightarrow \) middle layers \(\rightarrow \)tapetum
- (c)
epidermis\(\rightarrow \)middle layers \(\rightarrow \)endothecium \(\rightarrow \)tapetum
- (d)
tapetum \(\rightarrow \)middle layers \(\rightarrow \)epidermis\(\rightarrow \) endothecium
Which one is referred to as megasporangium?
- (a)
Ovary
- (b)
Ovules
- (c)
Locules
- (d)
Thalamus
Consider the following statements
i. Ovule remains attached to the placenta by means of a stalk called funicle
ii.The point of attachment of the body of the ovule with funicle is known as hilum
iii.Nucellus are parenchymatous tissues
- (a)
i & ii correct
- (b)
ii & iii correct
- (c)
i & iii correct
- (d)
i,ii& iii correct
Match the following
Column 1 | Column 2 |
(1) Porogamy | a. Casuarina |
(2) Chalazogamy | b. Cucurbita |
(3) Mesogamy | c. Cross pollination |
(4) Allogamy | d. Lily |
- (a)
1 d: 2c : 3 b : 4 a
- (b)
1 d: 2 a : 3b : 4 c
- (c)
1 d: 2 c : 3 a : 4 b
- (d)
1 d : 2 c : 3 a : 4 b
Polyembryony is observed in
- (a)
Apple
- (b)
Guava
- (c)
Strawberry
- (d)
Mango
Isogamous condition with non flagellated condition is found in
- (a)
Chlamydomonas
- (b)
Spirogyra
- (c)
Volvox
- (d)
Focus
Coconut water from a tender coconut is
- (a)
Free nuclear endosperm
- (b)
Inner most layers of the seed coat
- (c)
Degenerated nucellus
- (d)
Immature embryo
Which one is wrong statement?
- (a)
Mucor has biflagellate zoospore
- (b)
Haploid endosperm is typical feature of endosperms
- (c)
Brown algae have chlorophyll a and c and fucoxanthin
- (d)
Archegonia are found in bryophyte and gymnosperms
The ovule of an angiosperm is technically equivalent to
- (a)
megasporangium
- (b)
megasporophyll
- (c)
megaspore mother cell
- (d)
megaspore
Filiform apparatus is characteristic feature of
- (a)
generative cell
- (b)
nucellar embryo
- (c)
aleurone cell
- (d)
synergids
Filiform apparatus are finger-like projections present at the micropylar end of synergids of embryo sac.
Embryo sac occurs in
- (a)
embryo
- (b)
axis part of embryo
- (c)
ovule
- (d)
endosperm
Embryo sac occurs in ovule. Megaspore mother cell is developed inside the nucellus of the ovule and by a meiotic division it forms four megaspores, out of which three degenerate. The functional megaspore divides mitotically to form embryo sac.
An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is
- (a)
hemitropous
- (b)
campylotropous
- (c)
anatropous
- (d)
orthotropous
In hemitropous type, the ovule becomes curved and nucellus and embryo sac lie at right angles to the funicle, e.g. Ranunculaceae and Primulaceae.
Fertilisation involving carrying of male gametes by pollen tube is
- (a)
porogamy
- (b)
siphonogamy
- (c)
chalazogamy
- (d)
syngonogamy
In angiosperms, the male gametes are carried by the pollen tube and such type of fertilisation or fusion of male and female gametes or syngamy is called siphonogamy. It was discovered by Strasburger (1884).
Science of cultivation, breeding, marketing and arrangement of flowers is called
- (a)
arboriculture
- (b)
floriculture
- (c)
horticulture
- (d)
anthology.
A dithecous anther consists of (i) microsporangia,(ii) in each lobe.
- (a)
(i) (ii) four two - (b)
(i) (ii) two one - (c)
(i) (ii) two two - (d)
(i) (ii) four one
stamen or male reproductive organ of a flower is made up of two parts- a stalk-like filament and a knob like terminal anther. Each anther has two lobes which are attached at the back by a sterile band called connective. When both the anther lobes are present, the stamen is called bithecous (or dithecous). A dithecous anther is tetrasporangiate having four microsporangia. Each lobe has two microsporangia separated by a strip of sterile tissue. When a single anther lobe is present, the stamen is termed as monothecous.
Heterostyly as a contrivance for cross-pollination is found in
- (a)
Pennisetum
- (b)
Impatiens
- (c)
Primula vulgaris
- (d)
Oenothera
Heterostyly is the presence of 2-3 types of flower with different heights of styles and stamens. In diheterostyly (dimorphic heterostyly), there are two types of flower, pin eyed (long style and short stamens) and thrum eyed (short style and long stamens), e.g., Primula vulgaris (primrose), jasmine.
Select the correct order of endosperm types.
- (a)
Cellular, helobial, free nuclear
- (b)
Cellular, free nuclear, helobial
- (c)
Helobial, free nuclear, cellular
- (d)
Free nuclear, cellular, helobial
In free nuclear endosperm, the primary endosperm nucleus divides repeatedly without wall formation to produce a large number of free nuclei, e.g., maize,sunflower, Capsella, ete. In cellular endosperm every division of the primary endosperm nucleus is followed by cytokinesis. Therefore, endosperm becomes cellular from the very beginning, e.g., Balsam, Datura, Petunia. Helobial endosperm occurs in order Helobiales of monocots. The endosperm is of intermediate type between cellular and nuclear types e.g., Asphodelus.
The true embryo develops as a result of fusion of
- (a)
two polar nuclei of embryo sac
- (b)
egg cell and male gamete
- (c)
synergid and male gamete
- (d)
male gamete and antipodals.
In double fertilisation out of the two male gametes one fuses with egg or oosphere to perform generative fertilisation. Generative fertilisation is also called syngamy or true fertilisation. It gives rise to a diploid zygote or oospore.
Persistent nucellus is called as ________ and is found in_______.
- (a)
perisperm, black pepper
- (b)
perisperm, groundnut
- (c)
endosperm, black pepper
- (d)
endosperm, ground nut
In some seeds, remains of nucellus persist. This residual nucellus which persists in the seed is called perisperm, e.g., black pepper, coffee, castor, cardamum, Nymphaea.
Refer to the given figure and identify the parts labelled P, Q, R and S.
- (a)
P Q R S Seed Thalamus Mesocarp Endocarp - (b)
P Q R S Thalamus Seed Endocarp Mesocarp - (c)
P Q R S Seed Thalamus Endocarp Mesocarp - (d)
P Q R S Pericarp Seed Mesocarp Endocarp
The given figure is of false fruit of apple. Here P, Q, R and S are thalamus, seed, endocarp and mesocarp, respectively.
This is an example of a very old viable seed excavated from Arctic Tundra. The seed germinated and flowered after an estimated record of 10,000 years of dormancy. It is
- (a)
Victoria
- (b)
Lupinus arcticus
- (c)
Phoenix dactylifera
- (d)
Strobilanthus kunthiana
There are several records of very old yet viable seeds. The oldest one is of a lupine (Lupinus arcticus), excavated from Arctic Tundra. Seeds of Lupinus arcticus, atleast 10,000 years old were found in lemming burrows deeply buried in permanently frozen silt of Pleistocene age in unglaciated central Yuzon. They readily germinated in the laboratory and have since grown into normal healthy plants.
In case of polyembryony, if an embryo develops from the synergid and another from the nucellus, then the synergid embryo is (i) and nucellar embryo is (ii).
- (a)
(i) (ii) triploid haploid - (b)
(i) (ii) diploid haploid - (c)
(i) (ii) haploid diploid - (d)
(i) (ii) diploid triploid
In a fertilised embryo sac, the haploid, diploid and triploid structures are
- (a)
synergid, zygote and primary endosperm nucleus
- (b)
synergid, antipodal and polar nuclei
- (c)
antipodal, synergid and primary endosperm nucleus
- (d)
synergid, polar nuclei and zygote.
Synergids are a pair of haploid cells present at the micropylar end of embryo sac and constitute egg apparatus along with haploid egg.
Zygote is a diploid structure formed by fusion of male and female gametes whereas primary endosperm nucleus is triploid, formed by fusion of one male gamete with the secondary nucleus.
The phenomenon observed in some plants wherein parts of the sexual apparatus is used for forming embryos without fertilisation is called
- (a)
parthenocarpy
- (b)
apomixis
- (c)
vegetative propagation
- (d)
sexual reproduction
Apomixis is the term given to any phenomenon that leads to formation of embryo wherein parts of the sexual apparatus are used, but without fertilisation. Fertilisation is also absent in vegetative propagation, but parts of sexual apparatus are not involved. An example of apomixis is Citrus.
Assertion : In a microsporangium, the tapetal cells possess little cytoplasm and generally have a single prominent nucleus.
Reason : During microsporogenesis, the microspore mother cells (MMCs) undergo mitotic divisions to produce haploid microspore tetrads.
- (a)
If both assertion and reason are true and reason is the correct explanation of assertion.
- (b)
If both assertion and reason are true but reason is not the correct explanation of assertion.
- (c)
If assertion is true but reason is false.
- (d)
If both assertion and reason are false.
Tapetum is the innermost wall layer of a microsporangium. It nourishes the developing pollen grains. The tapetal cells enlarge radially and become filled with dense protoplasmic contents as well as nutrients. Tapetal cells are generally multinucleate or their nucleus becomes polyploid due to endoploidy. Microsporogenesis refers to the process of formation of haploid microspores (or pollen grains) from a microspore mother cell (MMC) or pollen mother cell (PMC) through meiosis (and not mitosis).
What is the function of filiform apparatus in an angiospermic embryo sac?
- (a)
Brings about opening of the pollen tube
- (b)
Guides the pollen tube into a synergid
- (c)
Prevents entry of more than one pollen tube into a synergid
- (d)
None of these
In castor, proliferation of the outer integumentary cells at micropylar region
- (a)
Lacks hygroscopic ability
- (b)
Attract ants and helps in mumecophily
- (c)
Is called epiblast
- (d)
Stores sugary substances
Pick out wrong Statement.
- (a)
Double fertilization is unique to angiosperms
- (b)
Sequoia, a gymnosperm, is one of the tallest tree
- (c)
Exine has apertures where sporopollenin is present
- (d)
Exine of pollen grains is made up sporopollenin
Plants with ovaries having only one or a few ovules are generally pollinated by
- (a)
Bees
- (b)
Butterflies
- (c)
Birds
- (d)
Wind
In angiosperms , functional megaspore develops into
- (a)
Endosperm
- (b)
Pollen sac
- (c)
Embryo sac
- (d)
Ovule