Sexual Reproduction of Flowering Plants Important Questions

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Very Short Answer Questions [1 Mark Questions]

Ques: What is the name of the closely assembled homogenous cells found inside the center of every microsporangium in the anther?

Ans: Sporogenous tissue

Ques: A plant came to India along with wheat that was imported from another nation and caused pollen allergy. Name the plant.

Ans: Parthenium

Ques: What is the reason behind the large number of pollen grains produced in Maize?

Ans: It happens so that pollination takes place as the pollens of Maize pollinate through the wind.

Ques: The compatible nature of pollen grain is determined by which part of gynoecium?

Ans: Stigma

Ques. Name the two component cells present in the egg apparatus in an embryo sac.

Ans: a) one egg or oosphere

b) two synergids

Ques: What is one common function performed by both, cotyledons and nucellus?

Ans: The common function produced by both, cotyledons and nucellus is nourishment.

Ques: Arrange the following in a correct sequence- make gamete, sporogenous tissue, microspore tetrad, pollen grains, and the potential pollen mother cell.

Ans: the correct sequence is as follows- Sporogenous tissue, potential pollen mother cell, microscope tetrad, pollen grain male.

Read More: Sexual Reproduction in Flowering Plants

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Short Answer Questions [2 Marks Questions]

Ques. The outer layer of a pollen grain is made up of a highly resistant substance. Identify that substance. When is that particular substance not present?

Ans: The outer layer of a pollen grain is called Sporopollenin. The substance is not present during germ pore.

Ques: The development of fruit in a plant happens through the ovary, however, in a few plants, this development of fruit happens through the thalamus.

1. Name both categories of fruits.
2. Give an example of each category

Ans:

1. The two categories of fruits are true fruits and false fruits
2. An example of true fruit is the mango and an example of false fruit is the apple.

Ques: Insects such as bees are considered dominant pollinating agents. Mention any four features of an insect-pollinated flower.

Ans: the four features of insect-pollinated flowers are as follows:

1. The size of the flowers is bigger
2. These flowers have colorful petals
3. These flowers have a fragrance to them
4. These flowers are rich in nectar

Ques: What is the difference between Geitonogamy and Xenogamy? Mention any two points.

Ans: The difference between Geitonogamy and Xenogamy are as follows:

Ques: Write one advantage and disadvantage of cleistogamy in flowering plants. 

Ans: One advantage of cleistogamy in flowering plants is that it maintains pure lines. The disadvantage is that it only sustains parental characters.

Ques: What does the term “inflorescence” mean?

Ans: Inflorescence is described as the arrangement and distribution of flowers on a peduncle. The peduncle is the axis of inflorescence. A flattened peduncle is known as a receptacle.

Ques: Define the following terms: ornithophily, chiropterophily, and malacophilous.

Ans: the definitions are as follows:

1. Ornithophily- It is the pollination that is carried out by small birds.
2. Chiropterophily- It is the pollination process performed by bats.
3. Malacophiluos- This pollination activity is performed by snails.

Read More: Sexual and Asexual Reproduction

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Long Answer Questions [3 Marks Questions]

Ques: What is the difference between microsporogenesis and megasporogenesis?

Ans: The differences between the two are as follows:

Ques: Describe the structure of the anatropous ovule. Also, draw a labeled diagram for the same.

Ans: A stalk is present in the anatropous ovule which is called the funicle and it is attached to the placenta. There is a connection between the funicle and the ovule which is termed helium. The ovule is enclosed by either one or more integuments and it has an aperture at the tip. The opening of the ovule is known as micropyle. To the exact opposite of the micropyle, lies the chalazal end which is the basal part of the ovule. Within the integuments containing a single embryo sac, there is a mass of cells called nucellus.

Ques: What are the advantages of sexual incompatibility?

Ans: The advantages of sexual incompatibility are as follows:

1. It inhibits self-pollination.
2. It makes the plant outbreeders, thus maintaining their vitality and vigor.
3. It allows for variation to occur as it provides adaptability to the changing environment.

Ques: Write about the structure of microsporangium. 

Ans: The microsporangium is circular and has four layers.

1. The outer layer is called the epidermis.
2. The second layer is known as endothecium. Within this layer, the cells develop thickening.
3. The middle layer is made up of 2 to 4 cells.
4. The innermost layer is termed tapetum. It is of large diploid and multinucleate cells.
5. There are four pollen sacs as well. Each of these pollen sacs has sporogenous tissue.

Read More: Asexual Reproduction In Plants

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Very Long Answer Questions [5 Marks Questions]

Ques: Describe the changes that take place in a flowering plant post-fertilization.

Ans: The following changes take place in a flowering plant post-fertilization:

1. Development of Endosperm: The usual method of the development of endosperm is of nuclear type. In this method, the triploid endosperm undergoes mitotic divisions without cytokinesis. Then, a structure of the cell wall occurs from the periphery and the endosperm stores food inside it.
2. Development of Embryo: The zygote is separated by the mitosis in a pro-embryo. Later, due to this development, there is a production of a globular and heart-shaped embryo. Then, this embryo finally becomes a horseshoe-shaped embryo that has either one or more than one cotyledon.

Ques: Answer the following questions: 

1. In a fertilized ovule, why are zygotes dominant for some time?
2. What is polyembryony? Give an example.
3. What is formed from the following parts of a fruit- ovary wall, outer integument, inner integument, zygote, primary endosperm, ovary, and nucellus?

Ans:

1. The reason why the zygote remains dominant for some time in a fertilized ovule is that the embryo gets developed after making the endosperm, Thus, the zygote is formed through the formation of endosperm and it does the function of supplying food to the developing embryo.
2. Polyembryony is when there is more than one embryo in a seed. For example, at times, more than one embryo gets formed within the embryo sac due to the splitting of an egg or by cleavage, endosperm, synergid, or antipodal.
3. The following things are formed from the following parts:

Ques: Answer the following questions: 

1. How is there more than one embryo in a seed of orange? Explain.
2. Are all these embryos genetically similar or one of a kind?

Ans:

1. When we squeeze an orange seed, we see many embryos because of polyembryony which is the formation of more than one embryo in a seed. The nuclear cells get formed into several embryos of varied sizes. This happens due to the formation of more than one egg in an embryo sac.
2. As there is no segregation of characters in such embryos, they are genetically similar.

Ques: What are the advantages of seeds to plant and to mankind?

Ans: Advantages of seeds to plants are–

1. Seeds have the ability to adapt better to new habitats after they are dispersed during seed germination.
2. Seeds store food inside them to provide enough nourishment to the seedlings.
3. The seed is hard; thus, it provides the utmost protection to the developing embryo.
4. As seeds are formed post-sexual reproduction, they lead to variations and genetic recombination.

Advantages of seed to mankind are– 

1. If they are stored and used properly, they provide us with food for a long span of time.
2. They are also extensively used to grow crops in favorable seasons.

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