Operculum - seed appendages, Biology

Assignment Help:

Operculum - Seed Appendages

The term operculum is applied to a plug-like structure formed in the micropylar portion of the seed by proliferation of cells at the tip of the inner integument or the nucellus. An operculum has been observed in seeds of many monocotyledonous families, such as the Commelinaceae, Musaceae, Lemnaceae and Zingiberaceae, and a few dicotyledonous families like Bignoniaceae and Nymphaeaceae.

In Lemna paucicostata, cells at the tip of the inner integument undergo a remarkable expansion after fertilization and form a dome-shaped, stopper- like operculum. Cells of the operculum are thick-walled and contain an orange-red substance. During germination of the embryo the operculum becomes detached from rest of the seed and facilitates emergence of the embryo.


Related Discussions:- Operculum - seed appendages

Effects on materials - air pollutants, Effects on Materials - Air pollutant...

Effects on Materials - Air pollutants Most air pollutants are reactive chemicals, so they react with most of the substances around. You may recall from your chemistry lessons

Different sources of infection, Different sources of infection: There a...

Different sources of infection: There are many sources of infection such as reservoirs, carrier organisms and lifeless objects. Reservoirs : A habitat where the disease cau

What volume of 1.20 m naoh solution must we add, You have 875 mL of a 0.37 ...

You have 875 mL of a 0.37 M acetic acid solution. What volume (V) of 1.20 M NaOH solution must you add in order to prepare an acetate buffer of pH = 4.36? (The pKa of acetic acid i

Photosynthetically active radiation, Photosynthetically Active Radiation ...

Photosynthetically Active Radiation This is usually in direct proportion with the incident solar radiation, you know that tropic$ are probably the best illuminated part of the

Hydrology, Hydrology Background: Hydrology is the study of the move...

Hydrology Background: Hydrology is the study of the movement and distribution of water resources. This is an important field of study in a dry climate like Utah. Although c

Preparation of dilutions - standard or total plate counts, Define Preparati...

Define Preparation of Dilutions - Standard or Total Plate Counts? 1. Serial dilution of homogenized sample in an appropriate diluent. Preparation of dilutions - Decimal dilu

What are the venous of the valves system, Q. What are the venous of the val...

Q. What are the venous of the valves system? What is their function? The valves of the venous system are structures inside the veins that permit blood to flow only in the norma

State the term - neuropsychological examination, State the term - Neuropsyc...

State the term - Neuropsychological Examination For a neuropsychological examination a battery of tests administered should include, at a minimum: Intelligence Tests

Prophase, Prophase This is the first and longest phase of mitosis .At i...

Prophase This is the first and longest phase of mitosis .At its beginning  all  10 nm segments   of chromatids (= chromonemata)  of the  duplicated  chromatin fibres of interph

Explain the proteins stabilize emulsions, Explain The proteins stabilize em...

Explain The proteins stabilize emulsions The proteins stabilize emulsions and contribute  physical  and rheological properties,  like thickness,  viscosity, elasticity   and  r

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd