Question
What is endosperm of angiosperms ? Describe its types.###What is endosperm ? Explain various types of endosperms.
✓
Answer
Endosperm : As a result of double fertilization and triple fusion, a nutritive tissue formed within the embryo sac by division of endosperm nucleus is called endosperm. It is an essential tissue because it surrounds and nourishes the embryo in the seeds of angiosperms.
Various types of endosperm on the basis fo development :
(1) Nuclear Endosperm : It this type of endosperm nucleus divides to form many free nuclei. There is no will formation at the time of the division. The free nuclei formed, arranges towards the periphery in the cytoplasm. A large central various appears in the embryo sac the wall formation may start after sometimes from periphery towards the centre of the sac. Example: capsella, Euphorbia, Malva, Citrus, etc.
(2) Cellular Endosperm : In this type of endosperm the primary endosperm nucleus divides repeatedly followed by immediate wall formation, Therefore, endosperm becomes cellular from the very beginning Example : Adoxa, Balsam, Datura, etc.
(3) Helobial Endosperm : This type of endospermis of intermediate type between cellular and nuclear type. The first division of endosperm results in the formation two cells lawrger micropylar and smaller chalazal ends. As the subsequent division in the micropylar and begins to increase, the chalazed end starts of degenerate. Finally like that of nuclear endosperm, the multinucleate stage is followed by wall formation. Examples Asophodelus, Eremurus, etc.
Various types of endosperm on the basis fo development :
(1) Nuclear Endosperm : It this type of endosperm nucleus divides to form many free nuclei. There is no will formation at the time of the division. The free nuclei formed, arranges towards the periphery in the cytoplasm. A large central various appears in the embryo sac the wall formation may start after sometimes from periphery towards the centre of the sac. Example: capsella, Euphorbia, Malva, Citrus, etc.
(2) Cellular Endosperm : In this type of endosperm the primary endosperm nucleus divides repeatedly followed by immediate wall formation, Therefore, endosperm becomes cellular from the very beginning Example : Adoxa, Balsam, Datura, etc.
(3) Helobial Endosperm : This type of endospermis of intermediate type between cellular and nuclear type. The first division of endosperm results in the formation two cells lawrger micropylar and smaller chalazal ends. As the subsequent division in the micropylar and begins to increase, the chalazed end starts of degenerate. Finally like that of nuclear endosperm, the multinucleate stage is followed by wall formation. Examples Asophodelus, Eremurus, etc.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
a. Draw the embryo sac of a flowering plant and label the following:
i. Central cell
ii. Chalazal end
iii. Synergids
b. Name the cell and explain the process it undergoes to develop into an embryo sac.
c. Explain the development of endosperm in coconut.
i. Central cell
ii. Chalazal end
iii. Synergids
b. Name the cell and explain the process it undergoes to develop into an embryo sac.
c. Explain the development of endosperm in coconut.
What is called immunity? How many types are there? Describe innate immunity.
Explain with an example, where a gene, which carries a major disadvantage in homozygous state, confers an advantage in heterozygous condition.
Give a note on sexually transmitted diseases.
- Explain the role of regulatory gene, operator, promoter and structural genes in lac operon when E.coli is growing in a culture medium with the source of energy as lactose.
- Mention what would happen if lactose is withdrawn from the culture medium.
Describe the functions of the following:
Epididymis.
Epididymis.
Ramesh is a small scale farmer and holds 2.5 acres of land. He would like to increase the yield in his farm. Rahul, a student of MSc. (Agriculture) advised him to go to the agricultural department centre of his locality to get biofertilisers according to the variety of the crop. He also suggested Ramesh to stop the use of chemical fertilisers.
- Explain the term biofertilisers.
- Name the biofertiliser that is used mostly in paddy fields.
- What are the values shown by Rahul?
What is Down’s syndrome? Give its symptoms and cause. Why is it that the chances of having a child with Down’s syndrome increases if the age of the mother exceeds forty years?
What is population explosion? Discuss the various reason of population explosion.
Work out a monohybrid cross upto F, generation, between two pea plants and two Antirrhinum plants, both having contrasting traits with respect to colour of flower. Comment on the patterns of inheritance in the crosses carried above.