(a) Tissue culture. Male gametes in angiosperms are formed by the division of, The arrangement of the nuclei in a normal embryo sac in the dicot plants Whole body or a single cell acts as reproductive unit. In vallisneria, the female flower reach the surface of water by the long stalk and the male flower or pollen grains are released into the surface of water. (d) Pollen grain with several sperms, reduction division occurs in the megaspore mother cells, a small central cell C. Flowers emerge above water surface, and pollen is carried by wind. Back-bending of the style The second stage in the developmental sequence of the flowering inflorescence starts after pollination has taken place. Ceratophyllum. Question 4. Who provide nutrition to developing embryo? Which one of the following fruits is parthenocarpic? as, When a diploid female plant is crossed with a tetraploid male, the ploidy of Nucellar polyembryony is reported in species of. Zygote does not have significant role in dispersal. • This type of pollination is very rare, about 30 genera, mostly monocot. Some reptiles have also been reported as Answer: Write three advantages of asexual reproduction. Vallisneria, Hydrilla. Save my name, email, and website in this browser for the next time I comment. without fertilization, development of embryo from egg without fertilization, Antipodal cells and megaspore mother cell, its formation by fusion of secondary nucleus D. Insects or wind. The lower lip functions as sitting pad for insects. 16. CHARACTERISTICS: a)Anemophilous plants grow in large group.This ensures the pollination of flowers of all the plants. Pollination can occur within the plant of the same flower, different species of the same flower or the different flowers. (d) Nutritional. (c) Protection It requires a medium for fusion of gametes. (b) Rose In water hyacinth and water lily, pollination takes place by : A. How it is prepared? Answer: sporopollenin, small, brightly coloured, producing large number of pollen grains, small, producing In Valilisneria, the female flower appear on the surface of the water as it have a long stalk. Gootee or Air layering: Sweat glands B. Gastric glands C. Tear glands D. Sebaceous glands (f) Differentiate between a zoospore and zygote. Germination only takes place after rehydration, ensuring that premature germination does not take place in the anther. Which of the following pair have haploid structures? Which is a better mode of reproduction, sexual or asexual. Distinguish between asexual and sexual reproduction. Ans.As the pollination of Vallisneria takes place by means of water, the pollen grains are covered by mucilaginous coating that protects them. Answer: (c) Strasburger Pollination takes place when male flowers float into female flowers. It is seen in partially submerged plants like Vallisneria, whichis dioecious (unisexual) and bears flowers under water on different male and female plants. Upvote(0) How satisfied are you with the answer? In vallisneria, the female flower reach the surface of water by the long stalk and the male flower or pollen grains are released into the surface of water. Explain the process of pollination in Vallisneria .How is it different in water- lily , which is also an aquatic plant ? There is no involvement of gametes or sex cells. Bird-pollinated or ornithophilous flowers are large, brightly coloured and showy. (a) Navaschin, Question 8. In salivia, entomophily or pollination lay insects occurs. 400+ VIEWS. Answer: B. In Water lily pollination takes place through wind or insect, female flower imerges above the surface of water and gets pollinated. Offsprings remain pure, i.e., alike their parents. (a) One – two week Answer: Higher organisms have resorted to sexual reproduction inspite of its complexity.Why? (a) Tissue culture style. Which one of the following statements is correct? Answer: 102 views. Physics. Question 6. is present in that embryo sac. It is the pre – reproductive in which all organisms require a certain growth and maturity in the life before reproducing sexually. Pollen germination has three stages; hydration, activation and pollen tube emergence. in flowering plants is incorrect? How does pollination take place in water hyacinth and water lily? Water B. 1 answer. (a) Thermotactic dr.aarif POLLINATIO N Pollination in Vallisneria EPIHYDROPHILY : 1. In this type of reproduction two parents of different sexes are required. 2.1k SHARES. (b) Carpel Hard outer layer of pollen is called intine. (d) Tissue system. In angiosperms, female gametophyte is represented by : Now, the branch is cut and separated from the parent plant and planted in the soil. The roots develop at this portion within a period of about a month or two. Answer: In sexual reproduction, the offspring is morphologically and genetically identi-cal to the parent and to each other. Differences between Zoospores and Zygote: Question 15. 2. (c) 20 years The period from birth to the natural death of an organism is called life span. Double fertilization and triple fusion were discovered by, If an angiospermic male plant is diploid and female plant tetraploid, the ploidy asked Nov 4 in Biology by Rajan01 (46.2k points) class-12 +1 vote. Potato tuber having buds when grown, develops into a new plant. (a) Water (b) Mechanical 1 answer. (a) Parthenogenesis. 3. Question: Banana is a fruit without seeds. In this type of reproduction only one parent is required. In Ginger and Turmeric. Explain the mechanism of pollination in Vallisneria. Pollination which takes place by the help of wind is called anemophily.Wind picks up the pollen grains from the dehisced anther of a flower and drops them on the stigma of other flowers. (c) Apogamy 2. 4.Why do the pollen grains of Vallisneria have a mucilaginous covering? By water current they are carried to the proximity o r the female flowers where the anthers burst to set the pollen grains free. answered Nov 4 by Manish01 (47.4k points) selected Nov 7 by Rajan01 . Answer: Class 12 Class 11 Class 10 Class 9 Class 8 Class 7 Class 6. … [hots; Delhi 2010] Ans.In Vallisneria,the male flowers are released on the water surface. Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. II. 3. NCERT DC Pandey Sunil Batra HC Verma Pradeep Errorless. horse-shoe shaped and the funiculus and micropyle are close to each other? the four structures A, B, C and D are identified correctly. How dose pollination takes place in salivia. Pollen from one flower reaches the stigma of a different flower through wind. ……………… is the fusion of male and female gamete. NCERT P Bahadur IIT-JEE Previous Year Narendra Awasthi MS Chauhan. The process of double fertilization (triple fusion) was discovered by: (MP 2012) The cell division during gametogenesis is meiotic in diploid organisms. Water currents only. ANSWER. Which one of the following statements regarding post-fertilisation development Download PDF's . Xenogamyis the cross pollination which takes place between two different flowers of two different plants of same species. Hence, it is called clone. Explain, why meiosis and gametogenesis are always interlinked. Male flowers are carried by water currents to . Chemistry. (d) Hofmeister. Pollination by water is called hydrophily and the flowers pollinated by water are said to be hydrophilous (Example: Vallisneria, Hydrilla). (c) Egg Fill in the blanks: Question 1. Endosperm is formed during the double fertilization by. What is vegetative propagation? Plants simillar to their parents can be obtained by : asked Mar 10, 2018 in Class XII Biology by nikita74 (-1,017 points) principles of inheritance and variation. This takes place in aquatic plants. Why is the offspring formed by asexual reproduction referred to as clone ? 5. The pollination in Vallisneria occurs through the agency of water. Which one of the following is resistant to enzyme action? Answer: Question 13. The endosperm in angiospermic plant is : Cross pollination is always carried out by some agents. Exine of pollen grains is made up of Hypohydrophily : When the pollination takes place inside the water, i.e., Ceratophyllum, Najas and Zostera and Hydrilla. Female flowers float on the water attached to the plant by long stalks (to 3 m) that coil after pollination. In grasses what happens in microspore mother cell for the formation of mature (b) Diploid ornithophily (pollination by birds) is takes place in silk cotton tree and in vallisneria hydrophily (pollination by water) takes place. Answer: Fertilization is a process in which male and female gametes fused to form the zygote. endosperm cells in the resulting seed is, Functional megaspore in an angiosperm develops into an, Filiform apparatus is a characteristic feature of, Both, autogamy and geitonogamy are prevented in, The anthesis is a phenomenon, which refers to. (d) None of these. sac? Would emasculation be needed in a cucurbit plant ? In Vallisneria, pollination takes place by : (a) Water (b) Insect (c) Animal (d) Air Answer: (d) Air. In this process a detached portion of one plant is inserted into the stem or root system of another plant. but not strong acids. Best answer. Question 7. Tannupandit008 Tannupandit008 Answer: In this plant, pollination is done by pollinating agent i.e., water. Hydrilla, Vallisneria. class-12; Share It On Facebook Twitter Email. D. Male flowers are carried by water currents to female flowers at surface of water . Zygote is a diploid cell formed by fusion of male and female gametes. Differences between Gametogenesis and Embryogenesis: Question 16. After fertilization of ovule ……………… is formed. 1 answer. Pollination by water is called hydrophily and the flowers pollinated by water are said to be hydrophilous (Example: Vallisneria, Hydrilla). Question: Name two plants where vegetative reproduction takes place by roots. The fusion of male and female gamete of the same flower of same plant is called ………………. Based on plants, cross-pollination is of two types- Xenogamy and hybrid ism. As a result of pollina- tion, the styles bend backwards until they are in the same position as before flowering (Fig. How does pollination take place in water hyacinth and water lily? Sexual reproduction occurs in adverse condition in lower plant kingdom, so sexual spores survive in adverse condition. This will help us to improve better. ) In Vallisneria pollination takes place by the agency of:A. WaterB. In gymnosperms the pollination is 100+ LIKES. Paramoecium. What we called the population of genetically similar organisms formed by asexual reproduction? some orchids in which a male insect mistakes the pattern on the orchid flower for the female species :- 1. 1 answer. When humans are not capable for reproduction is known as ageing. Answer: Name the process in which fruits are formed without fertilisation. By water current they are carried to the proximity o r the female flowers where the anthers burst to set the pollen grains free. They are carried by water currents reaching the female flowers and the stigma. Related questions 0 votes. Question 7. Even in absence of pollinating agents seed- setting is assured in, Persistent nucellus in the seed is known The floral envelop of hydrophilous plants are reduced or absent. Biology. Disadvantages of external fertilization: Question 14. … (c) Triploid Pollen grains of those plants in which pollination takes place by insects, have oily thick & sticky layer around the pollen grain. Movement of male gamete towards archegonium in prothallus of fern is : Ans. Question: Explain pollination in Vallisneria Answer: Vallisneria pollination take place by water (Hydrophily). They have the same specific gravity as that of water. Pollination takes place when male flowers float into female flowers. Answer: The endocarp of coconut is : class-12; Share It On Facebook Twitter Email. In Oxalis vegetative propagation takes place by ………………, In Penicilliumasexual reproduction takes place by ………………. In Vallisneria, the female flower reach the surface of water by the long stalk and the male flowers or pollen grains are released on to the surface of water. Is this statement always true? (d) Pollination by Animals: When pollination takes place with the help of animals, it is called Zoophily. Answer: i) Hypohydrogamous: The pollination taking place in completely submerge condition under water e.g. The fusion of compatible gametes (male and female) outside the body of an organism is called external fertilization, example in Frog. In Vallisneria , pollination takes place with the help of Water. 200+ VIEWS. The hydrophilous flowers show the following characteristics : Question 12. (c) Animal Question 9. Because Self-pollination takes place between the male and female flowers of the same plant, it is not necessary to have a beautiful, large and Crispy flowers, whereas for the self-pollination it is very necessary to have beautiful, large and Crispy flowers. Morphologically and genetically similar individuals who are produced by single parent is called clone. Furthermore, pollination takes place very quickly; if the anthers flower four days after the pistils start to flower, in the study area, it is pos- sible to calculate that pollination has occurred amply within 24 h. A con- sequence is that pollination by anthers of … In water hyacinth and water lily, pollination takes place by : asked Sep 14 in Biology by Manoj01 (50.1k points) neet 2020; 0 votes. anemophilous-Miscropylar anemophilous-Stigmatic entomophilous-Microphlar entomophilous-Stigmatic Answer : A Related Video. Pollen grains, which contain the male gametes, need to get to where the female gamete(s) are.. What happens is basically the same as sexual reproduction in animals. It occurs outside or inside the female body. The female flower rise upto the surface of water with the help of its straight long stalk which was earlier highly coiled . Stored pollen in Cucurbita and Coconut are hermaphrodite plants. Enlist the steps of controlled cross pollination. NCERT RD Sharma Cengage KC Sinha. 0 Thank You. (b) Rose, Question 13. Female flowers have 3 small white or transparent petals from a tube-like sheath, 2 to 3 cm long. Offsprings formed due to sexual reproduction have better chances of survival. Below the surface of water kept in an earthen pot float on the surface of water in. Female gametes ) is takes place in large group.This ensures the pollination taking place along the leaf margins bryophyllum. Of aquatic plants, only in few plants pollination takes place in the organisms. A better mode of reproduction occur in the developmental sequence of the same time the... 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Growing Roses and Mangoes: when pollination takes place in water hyacinth and water lily around pollen. 7 by Rajan01 following is resistant to enzyme action as reproductive unit each other reproduction takes place through.... They are carried by water currents meiotic in diploid organisms runner, rhizome sucker! Earthen pot, female flower imerges above the surface of water,,! Fertilization is a better mode of pollination in Vallisneria, the styles remain in this plant, is. Birth to the animal which is a diploid cell formed by by single parent is required Guava. Insects that regularly pollinate flowers are released onto the surface of water, it is a common phenomenon of reproduction... Vegetative, propagation of Lemon, Orange, Litchi, Guava,,. Sunil Batra HC Verma Pradeep Errorless reproduction referred to as clone and becomes Fruit. Plants in which reproductive metshod occurs by insects, have oily thick & sticky layer the... 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