Sexual Reproduction in Flowering Plants BIOLOGY - Sexual Reproduction in Flowering Plants

Self-pollination is fully ensured if:

Pollen grains are produced in-

The gynoecium in a flower is-

Fruit of coconut is:

In drupe of coconut, the mesocarp is:

The Zygote divides to form a ____________ which implant in uterus.

Differentiate between:
Hypocotyl and epicotyl.

Perisperm and pericarp.

Coleoptile and coleorrhiza.

Integument and testa.

Give an example of a plant which came into India as a contaminant and is a cause of pollen allergy.

What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?

Arrange the following terms in the correct developmental sequence:
Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gametes.

Mention two strategies evolved to prevent self-pollination in flowers.

Name the parts of an angiosperm flower in which development of male and female gametophyte take place.

Why is apple called a false fruit? Which part(s) of the flower forms the fruit?

What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.

What is apomixis and what is its importance?

What is meant by emasculation? When and why does a plant breeder employ this technique?

Explain the role of tapetum in the formation pollen-grain wall.

What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.

With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.

A flower of brinjal plant following the process of sexual reproduction produces 360 viable seeds.
Answer the following questions giving reasons:
How many ovules are minimally involved?

What is geitonogamy? Give an example. How does geitonogamy differ from xenogamy in plants?

For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Placenta is tissue present inside the ovary.
Reason: Placenta bears ovules.

For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Most of entomophilous pollination is done by bees.
Reason: Bee-pollinated flowers are highly coloured.

For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Cross pollination is the only means of pollination in unisexual flowers.
Reason: Self-sterility is the only way to prevent self-pollination in bisexual flowers.

For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Self-sterility inhibits self-pollination.
Reason: Dichogamy is the condition in which only self-pollination occurs.

For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Assertion: Perisperm is protective covering of seed and helps in dispersal and nutrition.
Reason: Pericarp is covering of fruit which is non-functional.

Read the following and answer any four questions from (i) to (v) given below:
In angiosperms, the pollen grains are being transferred from the anther to the stigma and is termed pollination. This phenomenon was first discovered by Camerarius (1694) in the end of seventeenth century. Pollen grains are immobile. They cannot reach the stigma by themselves. An external agent is required for this. The pollination is mainly of two types-self pollination and cross pollination. The diagram given below shows two plants of the same species showing different types of pollination.

1. What is transferred between the plants in the process indicated by arrow P?

1. Ova.
2. Pollen.
3. Nutrients.
4. Seeds.

2. Which of the following statements is correct regarding processes P, Q and R?

1. Processes P, Q and R introduce genetic variability in the offspring of sexually reproducing plants X and Y.
2. Wind serves as agent for process Q if plants X and Y belong to Genus Salvia.
3. Flowers of plants X and Y need to produce odour and nectar for completion of processes P and Q if they are entomophilous.
4. If plants X and Y belong to Genus Cannabis, then their flowers need to produce sticky and heavy pollens in very small amount for accomplishment of process Q.

3. Identify the processes P, Q and R.

S. No	P	Q	R
(a)	Geitonogamy	Xenogamy	Autogamy
(b)	Allogamy	Chasmogamy	Cleistogamy
(c)	Autogamy	Geitonogamy	Xenogamy
(d)	Geitonogamy	Allogamy	Autogamy

4. In Catliarantl1us, the growth of style brings the stigma in contact of ripe anthers present on the mouth of corolla tube. This is an example of:

1. Homogamy.
2. Cleistogamy.
3. Geitonogamy.
4. Xenogamy.

5. Which of the given processes represents a type of pollination that would result in greater adaptability of the particular species to potential environmental changes?

1. P.
2. Q.
3. R.
4. All of these.

Read the following and answer any four questions from (i) to (v) given below:

A typical angiospermic ovule is a small structure attached to the placenta by means of a stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Each ovule has one or two protective envelopes called integuments. Integuments encircle the nucellus except at the tip where a small opening called the micropyle is formed. Mature ovules are classified on the basis of funiculus. It can be orthotropous, anadromous, hernitropous, campylotropous, etc.

1. The body of the ovule consists of a mass of parenchymatous cells called:

1. Integuments.
2. Nucellus.
3. Hilum.
4. Funiculus.

2. Refer to the given figure and select the correct statement regarding it.

1. This type of ovule is found in cactus.
2. The micropyle comes to lie close to the funiculus due to unilateral growth of ovule.
3. It is most common type of ovule found in the members of Chenopodiaceae.
4. It is half inverted ovule.

3. Identify the parts labelled as A, B, C and D in the given figure and select the correct option.

S. No	A	B	C	D
(a)	Chalaza	Female gametophyte	Embryo sac	Micropyle
(b)	Chalaza	NuceIIus	Embryo sac	Micropyle
(c)	Micropyle	Egg	Embryo sac	Chalaza
(d)	Micropyle	Nucellus	Embryo sac	Chalaza

4. Mature ovules are classified on the basis of funiculus. If micropyle lie close to the funiculus, the ovule is termed as:

1. Orthotropous.
2. Anatropous.
3. Hemitropous.
4. Campylotropous.

5. In Asphodel us, ovule is:

1. Unitegmic.
2. Tritegmic.
3. Bitegmic.
4. Ategmic.

Read the following and answer any four questions from (i) to (v) given below:
Cross pollination is the transfer of pollen grains from the anther of a one flower to the stigma of a genetically different flower. It is performed with the help of an external agency which may be abiotic (e.g., wind, water) or biotic (e.g., insects, birds, bats, snails). The diagram shows the carpel of an insect pollinated flower.

1. What is the most likely reason for non germination of pollen grain Z?

1. Pollen grains X and Y were brought to the stigma earlier, therefore, their germination inhibited the germination of pollen grain Z.
2. Pollen grain Z was brought to the flower by wind, while pollen grains X and Y were brought to the flower by insect.
3. Pollen grain Z lacks protrusions that allow it to adhere properly onto the stigma surface.
4. Pollen grain Z comes from a flower of an incompatible species.

2. Which of the following best describes the function of the pollen tube?

1. It acts as a conduit to transport male gametes from the anther to the ovule.
2. It acts as a conduit to transport male gametes from the stigma to the ovule.
3. It contains key nutrients that serve to nourish the newly-formed zygote.
4. It digests the tissues of the stigma, style, and ovary.

3. Pollination of a flower in which the pollen is carried by an insect is called:

1. Anemophily.
2. Ornithophily.
3. Entomophily.
4. Malacophil.

4. Refer to the given characteristics of some flowers.

1. The stamens hang out of the flower, exposing the anthers to the wind.
2. The pollen grains are tiny and light.
3. The flower has a sweet scent.
4. The flower petals are brightly colored.

5. Pollenkitt is generally found in:

1. Anemophilous flowers.
2. Entomophilous flowers.
3. Ornithophilous flowers.
4. Malacophilous flowers.

Read the following and answer any four questions from (i) to (v) given below:
The pollen grains or microspores are the male reproductive bodies of a flower and are contained in the pollen sac or microsporangia. Each pollen grain consists of a single microscopic cell, possessing two coats: the exine and the in tine. The exine of a pollen grain is made of chemically stable material. Because of this, pollen grains are often very well preserved for thousands of years in soil and sediments.

1. One of the most resistant biological material present in the exine of pollen grain is:

1. Pectocellulose.
2. Sporopollenin.
3. Suberin.
4. Cellulose.

2. The exine possesses one or more thin places known as:

1. Raphe.
2. Germ pores.
3. Hilum.
4. Endothecium.

3. What is the function of germ pore?

1. Emergence of radicle.
2. Absorption of water for seed germination.
3. Initiation of pollen tube.
4. All of these.

4. What is the key advantage to the plant for having such strong pollen grain walls?

1. It protects the vital genetic material in the pollen grain.
2. It allows pollen to serve as a valuable fossil record for the study of ancient plants.
3. It prevents the pollen tube from growing out before the pollen grain reaches the stigma of a compatible species.
4. It gives weight to the pollen grain, allowing it to cling better to the body surfaces of insect pollinators.

5. The number of germ pores in dicots and monocots respectively are:

1. One and three.
2. Three and two.
3. Two and three.
4. Three and one.

Read the following and answer any four questions from (i) to (v) given below:
Many adaptations are found in flowers to achieve certain kind of pollination. The pollination achieved by insects is known as entomophily. The given diagram shows the cross-section of an anther of an insect pollinated flower.

1. Which of the following is/ are the function(s) of structure Y?

1. To carry waste products away from the anther.
2. To supply oxygen to the cells of the anther.
3. To transport food and mineral salts to the anther.
4. To supply water to the anther.

1. Conly.
2. C and D only.
3. A, B and D only.
4. A, B, C and D.

2. Which of the following most accurately describes the structures found in compartment X?

1. They contain two haploid nuclei resulting from meiosis.
2. They contain two haploid nuclei resulting from mitosis.
3. They contain two haploid male gametes, resulting from mitosis.
4. They contain a vegetative nucleus and pollen tube nucleus.

3. Which of the following is a distinctive characteristic of insect-pollinated flower?

1. All of them have nectar guides on their flowers.
2. They produce sugary fruit.
3. Their pollen grains tend to have rough surfaces.
4. They produce abundant quantities of pollen to make up for pollen grains that might be removed by the wind.

4. Which of the following are likely characteristics of the structures found in X and stamens of this plant?

S. No	Structure of X	Stamens
(a)	Abundant and light	Pendulous
(b)	Rough surfaces	Non-pendulous
(c)	Light and sticky	Pendulous
(d)	Coarse and sticky	Protrude outside the flower

5. Spiny or sticky pollen grains and large, attractively coloured flowers are associated with:

1. Hydrophily.
2. Entomophily.
3. Ornithophily.
4. Anemophily.