Sexual reproduction in flowers - class-XII
Description: sexual reproduction in flowers | |
Number of Questions: 91 | |
Created by: Muni Gupte | |
Tags: reproduction biology morphology of flowering plants and their function asexual and sexual reproduction in plants pollination botany plants: structure and function reproduction in flowering plants reproduction - the generating system sexual reproduction in flowering plants modes of reproduction reproduction in plants and animals morphology of flowering plants |
The nucellus of the ovule is:
-
haploid
-
diploid
-
triploid
-
polyploidy
In seed plants, Ovule is the part of the female reproductive organ. It consists of three parts; Integument ( forming its outer layer) Embryo sac ( female gametophyte) and a Nucellus that is the central and largest part of the ovule as a source of nutrients for the embryo and its ploidy is diploid i.e 2n
Nucellus is derived from the apical portion of the ovule primordium of the ovule primordium and function as a megasporangium i.e, the nucellus produces the megasporocyte, which will undergo meiosis to form megaspores that is the reason that nucellus of the ovule is diploid in nature.
So, the nucellus of ovule is diploid.
In Angiosperms, the common type of ovule is __________.
-
Anatropous
-
Orthotropous
-
Hemi anatropous
-
Campylotropous
Ovule represents
-
Microsporangium
-
Megasporangium
-
Gametophyte
-
Embryo.
Microsporangium | Pollen grains or male gamete |
---|---|
Megasporangium | Ovules or female gamete |
Gametophyte | Sexual phase in the life cycle of the plant |
Embryo | Part of a seed, which is formed after fertilization |
So, the correct answer is 'Megasporangium'
An angiospermic plant has to produce $88$ viable embryo sacs. How many meiotic divisions will be needed to produce equal number of female gametophytes by this plant?
-
$88$
-
$22$
-
$44$
-
$132$
The stalk of ovule is
-
Pedicel
-
Funiculus
-
Petiole
-
Rachiolo
The ovule of flowering plants are located inside the gynoecium and are connected to the placenta which is a parenchymatous tissue via a stalk-like structure called the funiculus.
The female reproductive system produces haploid (n) gametes called ............. or egg cell.
-
Ovum
-
Endosperm
-
Pollen grains
-
Synergids
A. Female gametes are also called eggs or ovum. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell.
Androphore is lightly differentiated in the flower of .................
-
$Rafflesia$
-
$Calycanthus$
-
$Salvia$
-
$Passiflora$
When in a flower, the internode between the corolla and the androecium is lengthened so as to raise the androecium high up in the air then that internode is called Androphore. It is an extension of the receptacle carrying the androecium and the gynoecium, typical of the caper family. In Passiflora, androphore is lightly differentiated.
When pollen tube enters through the base of a funiculus or the integument the phenomenon is known as
-
Porogamy
-
Chalazogamy
-
Mesogamy
-
Isogamy
When pollen tube enters through the micropyle, the phenomenon is known as porogamy. When pollen tube enters to the embryo sac through the tissue of the chalaza, the phenomenon is known as chalazogamy. When pollen tube enters through the base of a funiculus or the integument, the phenomenon is known as mesogamy. Isogamy is a form of sexual reproduction that involves fusion of gametes of similar size and structure.
Ovule is comparable to ............
-
Megasporangium
-
Microsporangium
-
Microsporophyll
-
Megasporophyll
Ovule means 'small egg'. In seed plants, the ovule is the surface that gives rise to and contains the female reproductive cells. It consists of three parts: the integuments form its outer layers, the nucellus and female gametophyte in its center. The female gametophyte specifically termed as megagametophyte is also called the embryo sac in angiosperms.
Nurse tissue of ovule is .............
-
Nucellus
-
Chalaza
-
Hilum
-
Micropyle
The mature ovule contains in its central part a region called the nucellus that in turn contains an embryo sac with eight nuclei, each with one set of chromosomes. The two nuclei near the centre are referred to as polar nuclei. In the pines, the female gametophyte develops within the tissues of the nucellus and acquires abundant food reserves. The proembryo forms after a period of free-nuclear division in the zygote, and the tier of cells above the basal four then elongates to form a suspensor which pushes the embryonic group deep into the gametophyte.
Select the correct match.
List I | List II | ||
---|---|---|---|
A | Endothecium | 1 | Nutritive layer |
B | Tapetum | 2 | Single flower |
C | Tulip | 3 | Floral organs are borne |
D | Receptacle | 4 | Middle layer of anther |
-
A- 4, B- 1, C- 2, D- 3
-
A- 1, B- 4, C- 3, D- 2
-
A- 3, B- 4, C-2, D- 1
-
A- 2, B- 3, C- 4, D- 1
Endothecium is defined as the lining of the inner cavity of the anther. It is present as a middle layer.
The cotyledon in monocot plant is one and
-
Lateral
-
Terminal
-
Basal
-
Vertical
The root cell of wheat plant has 42 chromosomes. What would be the number of chromosomes in the synergid cells?
-
7
-
14
-
21
-
28
The pollen tube ultimately enters an ovule through the micropyle and penetrates one of the sterile cells on either side of the egg ( synergids). These synergids begin to degenerate immediately after pollination.
Synergids are haploid in nature. Thus, if root cell has 2n = 42, synergids will have n = 21.
The point of attachment of funicle with chalazal end is called as
-
Placenta
-
Integument
-
Nucellus
-
Hilum
The hilum is the point of attachment of funicle with the chalazal end. It is the point where ovule attaches to the base. It is generally present as an eye of the seed as it is present as a scar.
Assertion : Most common type of ovule is anatropous.
Reason : Anatropous ovule is horse-shoe shaped.
-
Both assertion and reason are true and reason is a correct explanation of the assertion.
-
Both assertion and reason are true but reason is not a correct explanation of the assertion.
-
Assertion is true but Reason is false
-
Both Assertion and Reason are false
-
Assertion is false but Reason is true
The ovules where micropyle come to lie close to the funiculus due to unilateral growth of the ovule are called anatropous. This is the most common type of ovule in angiosperms where the curvature of the ovule also affects the nucellus so that the later becomes horse shoe-shaped. The ovule is called amphitropous.
Assertion: In hemianatropous ovule, the funicle lies parallel to body of ovule.
Reason: Here, body of ovule has rotated by $90^{o}$.
-
Both assertion and reason are true and reason is a correct explanation of the assertion.
-
Both assertion and reason are true but reason is not a correct explanation of the assertion.
-
Assertion is true but Reason is false
-
Both Assertion and Reason are false
-
Assertion is false but Reason is true
When funicle lies at right angle to body of ovule and micropyle, the ovule is called hemianatropous or body of ovule has rotated by $90^{o}$.
The megasporangium of the angiosperms on fertilization gives rise to
-
A fruit
-
Seed
-
An embryo
-
Cotyledons
The nucellus is a part of the inner structure of the ovule, forming a layer of diploid (sporophytic) cells inside the integuments. It is structurally and functionally equivalent to the megasporangium. In some plants, the diploid tissue of the nucellus gives rise to a seed through a mechanism of asexual reproduction called nucellar embryony.
Ovule is called
-
Megasporangium
-
Microsporangium
-
Integumented microsporangium
-
Integumented megasporagium
What would be the number of chromosomes in the cell of the aleurone layer in a plant species with 8 chromosomes in its synergids?
-
32
-
8
-
16
-
24
Synergid is one of two small, short-lived nuclei lying near the egg in the mature embryo sac of a flowering plant. The synergids are part of the egg apparatus and are thought to help the pollen nucleus reach the egg cell for fertilization.
A nutritive inner region of integument is?
-
Amphithecium
-
Endothecium
-
Endothelium
-
Endostomium
The point at which funiculus touches the ovule is
-
Chalaza
-
Hilum
-
Raphe
-
Endothelium
Out of linear tetrad which one is the functional megaspore
-
Micropylar
-
Any of the middle ones
-
Chalazal
-
Any of the four
Orthotropous ovules occur in
-
Pisum sativum
-
Solanum nigrum
-
Polygonum
-
Helianthus
A mass of parenchymatous tissue forming the bulk of ovule is
-
Obturator
-
Female gametophyte
-
Nucellus
-
Endosperm
Secondary nucleus formed by the fusion of two polar nuclei is also called
-
Vegetative nucleus
-
Definitive nucleus
-
Generative nucleus
-
Primary endosperm nucleus
The most common type of ovule is
-
Orthotropous
-
Hemitropous
-
Anatropous
-
Campylotropous
Name the type of ovule in which hilum, chalazal and micropyle come to lie nearby.
-
Campylotropous
-
Amphitropous
-
Both A and B
-
Hemitropous
• Campylotropous ovule- This type of ovule is similar to Anatropous ovule but the curvature is less than that of an anatropous ovule. Micropyle is near to the funiculus. Chalaza and micropyle lie in the straight line but hilum is at 90° to the micropyle.
Archesporium of ovule is
-
Single celled derived from nucellar epidermis
-
Single celled derived from nucellar hypodermis
-
Multicellular derived from nucellar epidermis
-
Multicellular derived from nucellar hypodermis
In the ovule or megasporangium, during the process of megasporogenesis, a hypodermal cell functions as a archesporium cell and becomes more prominent because of large size, denser cytoplasm and large nucleus. In tenuinucellate ovules, archesporial cell directly functions as megaspore mother cell while in crassinucellate ovules, archesporial cell divides periclinally to form an outer parietal cell and inner primary sporogenous cell that functions as megaspore mother cell.
Ovule is inverted with body fused to funicle, micropyle lying close to hilum and facing the placenta. It is?
-
Hemitropous
-
Orthotropous
-
Anatropous
-
Campylotropous
•Hemianatropous ovule- The body of ovule is turned through 90° and micropyle and chalaza lie in a straight line but funiculus is at right angle or 90° with both these two.
The body of ovule lies straight in continuation of funicle, with funicle chalazal and micropyle in straight line. The type of ovule is?
-
Anatropous
-
Orthotropus
-
Hemitropous
-
Amphitropous
Circinotropous ovule occurs in
-
Opuntia
-
Ranunculus
-
Polygonum
-
Cicer
Body of the ovule is straight but at right angles to the funicle. It is
-
Orthotropous
-
Campylotropous
-
Hemitropous
-
Amphitropous
•Orthotropous ovule is the simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza and funiculus lie in one vertical plane.
Which is diploid structure?
-
Pollen grains
-
Egg
-
Megaspore
-
MMC
The ovule of an angiospherem is technical equivalent to
-
Megaspore
-
Megasporangium
-
Megasporophyll
-
Megaspore mother cell
The placentas consists an enlarged basal portion which is called as ovary bearing one or more ovules also called as integumented megasporangium.
Match the columns and select the correct combination.
Column I | Column II | ||
---|---|---|---|
(a) | Ovule | 1. | Endosperm |
(b) | Funiculus | 2. | Aril |
(c) | Nucellus | 3. | Seed |
(d) | Polar nuclei | 4. | Perisperm |
-
a- 3, b- 2, c- 1, d- 4
-
a- 3, b- 2, c- 4, d- 1
-
a- 1, b- 2, c- 3, d- 4
-
a- 2, b- 3, c- 1, d- 4
Type of ovule present in Opuntia is
-
Amphitropous
-
Campylotropous
-
Circinotropous
-
Orthotropous
In ovule, cuticle is present over
-
Outer part of integument
-
Outer part of nucellus
-
Surface of both nucellus and integuments
-
None of the above
Which one produces callose for breaking plasmodesmal connections among microspore mother cell?
-
Microspore mother cells
-
Sporogenous cells
-
Tapetum
-
Middle layers
Match the columns and choose the correct combination.
I | II | ||
---|---|---|---|
1. | Funicle | a. | Small opening of ovule |
2. | Integument | b. | Stalk of ovule |
3. | Chalazal | c. | Protective envelopes of ovule |
4. | Hilum | d. | Junction part of ovule and stalk |
5. | Micropyle | e. | Basal part of ovule |
-
1- b, 2- c, 3- e, 4- d, 5- a
-
1- a, 2- c, 3- a, 4- d, 5- e
-
1- b, 2- c, 3- a, 4- d, 5- e
-
1- b, 2- d, 3- e, 4- a, 5- c
Ovules of Capsella and Pisum sativum are
-
Orthotropous
-
Anatropous
-
Amphitropous
-
Campylotropus
• Orthotropous ovule - The simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza, and funiculus lie in one vertical plane. Examples: all gymnosperms, Polygonum.
Tetrad of megaspores is generally
-
Tetrahedral
-
Linear
-
Decussate
-
Isobilateral
Ovule of Opuntia is
-
Campylotropus
-
Amphitropous
-
Circinotropous
-
Hemitropous
The placenta is attached to the developing seed near the
-
Testa
-
Hilum
-
Micropyle
-
Chalaza
The placenta is attached to the developing seed near hilum. It is the scar located nearthe edge where seed breaks from stalk of funiculus, i.e., connecting the seed with fruitwall and placenta.
Which of the following pairs of terms is a correct match?
-
Ovule-egg
-
Pollen grain-sperm
-
Seed-zygote
-
Embryo sac-female gametophyte
-
All of the above
Ovule- The ovule is the structure that gives rise to and contains the female reproductive cells. The ovule is located inside the portion of the flower called the gynoecium.
In ovule, functional megaspore develops into ______________.
-
Pollen mother cell-PMC
-
Megaspore mother cell-MMC
-
Embryosac
-
Both 2 and 3
From which part of the ovary do seeds and fruit develop?
-
Ovaries; Ovules
-
Ovules; Ovaries
-
Ovules; Stamens
-
Stamens; Ovaries
The ovule develops into seed and ovary develops into fruit and seeds are enclosed within the fruit. Both are result of fertilisation in angiosperm plant.
In ovule, endothelium is
-
Nucellus
-
Nucellus surrounding embryo sac
-
Tissue near chalaza
-
Inner part of integument
In 82% of angiosperm families, ovule is
-
Anatropous
-
Orthotropous
-
Amphitropous
-
Circinotropous
Choose the correct answers from the alternatives given.
The ovule is comparable to
-
megasporangium
-
microsporangium
-
megasporophyll
-
microsporophyll
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s), forming its outer layer(s), the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its centre.
Ovule in which funicle, chalaza and micropyle occur in one vertical plane is _________.
-
Anatropous
-
Orthotropous
-
Amphitropous
-
Campylotropous
Those ovules in which the funicle, chalaza and micropyle lie in one straight line are called orthotropous ovules. Example, Urticaceae.
Starting from the Innermost part, the correct sequence of parts in an ovule are.
-
Egg, nucellus, embryo sac, integument
-
Egg, embryo sac, nucellus, integument
-
Embryo sac, nucellus, integument, egg
-
Egg, integument, embryo sac, nucellus
Egg cell is inside the embryo sac in the ovule. The embryo sac is further enclosed by the parenchymatous tissue, nucellus, which provides nutrition to developing embryo. Nucellus is ultimately surrounded by integuments.
If spores have 10 chromosomes and 20 picogram DNA then what would be the chromosome number and DNA amount in spore mother cell at the end of S-phase in the life cycle of the same plant?
-
40 chromosomes and 80 pg DNA
-
20 chromosomes and 80 pg DNA
-
20 chromosomes and 40 pg DNA
-
40 chromosomes and 40 pg DNA
State whether the following statements are true or false.
Ovules are classified on the basis of the position of micropyle with respect to funicle.
-
True
-
False
In seed plants, the ovule ("small egg") is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s) form its outer layer(s), the nucellus (or remnant of the megasporangium), and female gametophyte (formed from haploid megaspore) in its centre. Mature ovules i.e. megasporangia in angiosperms are mainly of five types. The principle of classification is based on the position of the micropyle, chalaza and hilum with regard to one another and also to the placenta.
Following meiosis in ovules, how many megaspores are formed?
-
Two
-
Four
-
Six
-
Eight
The ovule is the structure that gives rise to and contains the female reproductive cells. The megaspore is produced inside the nucleus of the ovule. During megasporogenesis, the megasporocyte or megaspore mother cell, undergoes meiosis to produce initially four haploid cells (the megaspores). After megasporogenesis, the megaspore develops into the female gametophyte (the embryo sac) in a process called megasporogenesis
The part of the flower that contains ovules is
-
Carpel
-
Stamen
-
Petal
-
Sepal
The carpel is one of the leaflike, seed-bearing structures that constitute the innermost whorl of a flower. The seeds of flowering plants are enclosed inside an ovary which contains ovule. The ovary is part of a flower's female reproductive structure called a carpel. A flower can have one or more carpels. If there are many carpels, they can be separate or fused together. Together, all the carpels are called a gynoecium, or a pistil.
What is the function of filiform apparatus in an angiospermic embryo sac?
-
Brings about opening of the pollen tube
-
Guides the pollen tube into a synergid
-
Prevents entry of more than one pollen tube into a synergid
-
None of these
The synergid cell wall forming an extremely thick structure at the micropylar end is called the filiform apparatus. It bears several finger-like projections into the structure of synergid cytoplasm. The function of filiform apparatus is to guide entry of pollen tube and release of sperm cells.
-
Integument
-
Exine
-
Endostomium
-
Cuticle
A non-nutritive structure is
-
Tapetum
-
Endosperm
-
Integument
-
Palisade parenchyma
Study of fruit is known as
-
Pomology
-
Palynology
-
Dendrology
-
Anthology
Pomology (from Latin pomum (fruit) + logy) is a branch of botany that studies and cultivates fruit.
Development of seed from an unfertilised egg is called as
-
Vivipary
-
Parthenocarpy
-
Apomixis
-
Apospory
After fertilization____develops into seed and___into fruit.
-
Endosperm and Ovary
-
Ovary and ovule
-
Embryo sac and ovary
-
Ovule and ovary
Plant fertilization is a process in which a male gamete, pollen, is transferred to the female reproductive organ to fuse with an ovule, as a part of the sexual reproduction. After fertilization, the ovule develops into a seed and the ovary develops into the fruit.
How many generation and genotypic cells are present in angiosperm seeds.
-
Three and two respectively
-
One and two respectively
-
Two and three respectively
-
One and three respectively
Identify the incorrect statement.
-
Drupe develops from monocarpellary inferior ovary with stony endocarp
-
Phyllode is analogous to cladophyll
-
Supporting roots arise from lower nodes in maize
-
Axillary buds are modified into woody, pointed structures in Citrus
Seed coat is formed by
-
Integument
-
Nucellus
-
Fruit wall
-
None of the above
Integument is an envelope of one or more layers, each of two or more cell layers, covering the ovule, leaving only a pore, the micropyle, through which the pollen tube can enter. It may develop into the testa or seed coat. Seed coat is the outer protective covering of a seed.
The structures develops into the seed once fertilization has occurred is
-
Integument
-
Cotyledon
-
Ovule
-
Ovary
-
Endosperm
The event of double fertilization and subsequent growth and development results in the development of ovule into the seed. Each seed contains a young plant embryo and nutritive tissue (the endosperm), both of which are surrounded by a protective seed coat (derived from integument). Monocots have persistent endosperm that serves as amain source of food in the mature seed. Eudicots endosperm nourishes the developing embryo and subsequently stores food in its cotyledons. During development of seed from an ovule following fertilization, the ovary wall surrounding it enlarges and develops into a fruit wall while ovary makes fruit. Thus, the correct answer is D
The structures that develops into the fruit once fertilization has occurred is
-
Integument
-
Cotyledon
-
Ovule
-
Ovary
-
Endosperm
The event of double fertilization and subsequent growth and development results in the development of ovule into the seed. Each seed contains a young plant embryo and nutritive tissue (the endosperm), both of which are surrounded by a protective seed coat (derived from integument). Monocots have persistent endosperm that serves as a main source of food in the mature seed. Eudicots endosperm nourishes the developing embryo and subsequently stores food in its cotyledons. During development of seed from an ovule following fertilization, the ovary wall surrounding it enlarges and develops into a fruit wall while ovary makes fruit. Thus, the correct answer is D
The endosperm tissue in plants
-
Differentiates to form root structures
-
Provides nutrients to the plant embryo
-
Gives rise to male gametes that make up pollen
-
Makes up the photosynthetic cells inside the leaves
-
Forms the tissues that transport water and nutrients
The endosperm is the tissue produced inside the seeds of the flowering plants by triple fusion of two central nuclei and one male nuclei in embryo sac. This tissue surrounds the embryo and provides nutrition to it in the form of starch while in some seeds these are completely absorbed by the time they mature, in others, the endosperm is present till the seeds germinate.
The monocotyledonous seed consists of one large and shield shaped cotyledon known as
-
Aleurone layer
-
Scutellum
-
Coleoptile
-
Hilum
-
Coleorhiza
The scutellum is referred to the eqivalence of a thin cotyledon in monocots. It is very thin with high surface area, and serves to absorb nutrients from the endosperm during germination.
Study of seeds is a part of
-
Pomology
-
Morphology
-
Vegetative morphology
-
Reproductive morphology
Study of seed is part of reproductive morphology because during study of seed, we observe the processes occuring after the sexual reproduction of plants and its growing into a plant.
The correct option is 'Reproductive morphology'.
Which one is the national fruit of India?
-
Mango
-
Banana
-
Orange
-
Cashewnut
National fruit of India is Mango (Mangifera indica).
The remnants of nucellus present in the seed constitute
-
Endosperm
-
Endocarp
-
Perisperm
-
Aril
The nucellus is generally used up during the development of embryo but in some cases it remains outside the endosperm in the form of a thin layer, called perisperm.
Seed of black pepper is
-
Endospermic
-
Exalbuminous
-
Acotyledonous
-
Perispermic
A. Endospermic seed- Reserve food material present in endosperm.
Ovule integument gets transformed into
-
Seed
-
Seed coat
-
Fruit wall
-
Cotyledons
Identify the wrong statement regarding post fertilization development.
-
Ovary wall develops into pericarp.
-
Outer integument of ovule develops into tegmen.
-
Ovule develops into seed.
-
Ovary develops into fruit.
Pericarp of fruit develops from
-
Wall of ovary
-
Nucellus
-
Funicle
-
Seed coat
The outer most layer of the fleshy fruits is called as pericarp developed from the ovary wall of the flower and surrounds the seeds. Fruits are the mature ovaries of one or more flowers.
A seed is formed from
-
Ovule
-
Embryo
-
Embryo sac
-
Ovary
In Pea, wrinkling of seeds is due to nonformation of starch because of the absence of enzyme
-
Amylase
-
Invertase
-
Branching enzyme
-
Diastase.
In pea, the gene which controls starch synthesis also controls the shape of the seed.
In the pea plant with wrinkled seeds, this gene is not involved in the synthesis of starch due to the absence of enzyme starch synthase. It is a branched enzyme.
So, the correct option is ‘Branching enzyme’.
How many meiosis are required for the formation of 100 grains of wheat.
-
100
-
200
-
150
-
125
Choose the correct answers from the alternatives given.
After fertilization, fruit is derived from
-
endosperm
-
ovule
-
ovary
-
microsporophyll
Fruits are produced only by flowering plants (angiosperms). Following pollination of the flower, the fertilized ovules develop into seeds while the surrounding ovary wall forms the fruit tissue, or pericarp.
Which of the following parts of the flower develops to become a fruit?
-
Stigma
-
Style
-
Ovary
-
Stamen
A seed contains
-
A seed coat
-
An embryo
-
Stored food
-
All of these
A seed is an embryonic plant enclosed in a protective outer covering. Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule. Seed has endosperm that stores food to provide nutrition to the embryo. The formation of the seed is part of the process of reproduction in seed plants
In the plant part having two generations is
-
embryo
-
unfertilized ovule
-
germinated pollen grain
-
seed
Plant part having two ages, one inside the other is seed. Seed is a develop ovule comprising of the embryonic plant along with the putaway nourishment material.
Active form of phytochrome for seed germination is
-
P$ _{r}$-form
-
P$ _{fr}$-form
-
Both of A and B
-
None of the above
The main photoreceptor for photoperiodism and many other light-initiated plant responses is phytochrome, a family of about five blue-green pigment proteins, each of which is coded for by a different gene. Phytochrome is involved in the light requirement that some seeds have for germination. Seeds with a light requirement must be exposed to light containing red wavelengths. Exposure to red light converts $P _r$ to $P _{fr}$ and germination occurs. When $P _{fr}$ absorbs far-red light it is converted back to $P _r$. Hence, red light makes $P _{fr}$, far-red light makes $P _r$. In plants at least $P _{fr}$ is the physiologically active or "signalling" state.
Choose the correct answers from the alternatives given.
.After fertilization the seed coats develop from
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integuments
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chalaza
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nucellus
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embryo sac
Seeds are the product of the ripened ovule, after fertilization by pollen and some growth within the mother plant. The embryo is developed from the zygote and the seed coat from the integuments of the ovule.
Which of the following structures is unique to the seed of a monocot?
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Coleoptiles
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Radicle
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Seed coat
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Endosperm
The ovary ripens to form fruit.
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True
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False
As the ovules develop into seeds, the ovary begins to ripen and the ovary wall becomes fleshy and forms a hard outer covering to protect the fruit. Fruit is also called as ripened ovary. So the given statement is true.
Testa of seed is produced from
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ovary wall
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hilum
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outer integument of ovule
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funicle
A seed develops from an ovule after fertilisation. It consists of a tough coat called testa enclosing an embryo which is made up of plumule, radicle or cotyledons. It is produced from an outer integument of the ovule.
Pollen grains of flower pollinated by wind or insects are not ............
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Rough and sticky
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Large and showy
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Rough and dry
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Smooth and dry
Pollen grains to be carried by wind as well as by insects will not be heavy in weight or showy. This is because it causes the wind as well as insects tough to perform pollination. They prefer light weight as well as winged ones.
Wind pollinated plants differ from insect pollinated plants in having ....
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Small petals and sticky pollen
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Small coloured petals and heavy pollen
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Coloured petals and large pollen
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No petals and light pollen
Wind pollinated plants will have light weight pollens which are mostly winged and are thus easy to be carried away by wind. Whereas the plants where the pollinating agents are insects, the petals will be bright and scented so that the insects get attracted to it and acts as pollinator.
A very close relationship between flower and pollinating agent is best exhibited by
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Yucca
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Avena
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Salmalia
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Pisum
A very close relationship between flower and pollinating agent is best exhibited by Yucca as there is a mutually rewarding relationship between Yucca plant and species of moth. They cannot complete their life cycle without each other. The moth lays egg in the locules of the ovary. The larva uses some of the seeds as food. In turn, the flowers are pollinated by the moth.
In Salvia the pollination is affected by
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Water
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Air
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Animals
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Insects
Nectar is produced in saliva to lure pollinators such as insects and the process of pollination continues from one flower to the other flower and so on.